Current date: 2026-10-15

Setting default datestamp limit: 0

Datestamp limit: 2026-10-15 (0 days ago)

Created/updated limit: 2026-10-08 (7 days ago)

Suggested sets: physics, physics:astro-ph, physics:gr-qc, physics:physics

Setting default set: physics

OAI-PMH request: http://export.arxiv.org/oai2?verb=ListRecords&from=2026-10-15&until=2026-10-15&set=physics&metadataPrefix=arXiv

Scoring abstracts

Number of records retrieved: 873

Keyword score statistics

score 9 -- 1 abstracts

score 8 -- 2 abstracts

score 7 -- 3 abstracts

score 6 -- 3 abstracts

score 5 -- 6 abstracts

score 4 -- 6 abstracts

score 3 -- 7 abstracts

score 2 -- 24 abstracts

in total -- 52 abstracts

Articles that appeared on 2026-10-15

[abstract 1 / 52] Wow! (score: 9)
arXiv:2610.20065 [pdf, ps, other]

Title: Optical constraints on intranight variability in TeV HBLs from a two-year Asiago Schmidt monitoring campaign

Authors: Domenico Impiombato, Giacomo Bonnoli, Elisa Prandini, Luca Zampieri, Irene Albanese,

Comments: 18 pages, 3 figures, 4 tables

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We present a two-year homogeneous optical monitoring campaign of three TeV-emitting high-SYNCHROTRON-peaked BL Lac objects, 1ES 1959+650, H 1426+428, and PG 1553+113, carried out with the Asiago Schmidt 67/92 cm telescope. TeV BLAZARs are key targets in high-energy astrophysics, relevant for RELATIVISTIC JET physics, particle acceleration, multiwavelength variability studies, and, in selected cases, multimessenger programmes. In this context, dense optical monitoring provides a low-energy SYNCHROTRON tracer of JET activity over temporal baselines that are difficult to cover continuously with high-energy facilities. The dataset consists of more than 17,000 R- and I-band photometric measurements obtained over 957 source-filter observing sessions between 2024 February 1 and 2026 January 31, for a total monitoring time of about 420 h. We applied a uniform differential-photometry and classical F-test framework based on two independent comparison-star pairs. Robust IDV is detected only in H 1426+428, with 15 out of 43 analysed sessions classified as variable in the R band and 5 out of 40 in the I band. No significant IDV is detected in 1ES 1959+650 or PG 1553+113 within the adopted statistical framework. For H 1426+428, the corresponding duration-weighted duty cycles, computed using only variable sessions with a measured local characteristic timescale, are 28.0% in the R band and 7.0% in the I band. The inferred local extrapolated doubling/halving timescales are of the order of 5-15 min in the observer frame. These results indicate that rapid optical SYNCHROTRON variability in TeV HBLs is intermittent and state-dependent. They also show that robotic small- and medium-aperture optical facilities can provide valuable long-term support for high-energy monitoring programmes by supplying dense, uniform, and repeatable optical coverage.

[abstract 2 / 52] Wow! (score: 8)
arXiv:2610.20495 [pdf, ps, other]

Title: A Parsec-Scale Transient High-Frequency-Peaked Radio Source in the Very Large Array Sky Survey Brightening and Fading over a Decadal Timescale

Authors: Yuyang Chen, B. M. Gaensler, Maria R. Drout, Dillon Z. Dong, Emmanuel Momjian, Tracy Clarke, Wendy Peters, Emil Polisensky, Ariel D. Amaral, Katie Auchettl, Ylva Götberg, Kovi Rose, Peter Senchyna,

Comments: 35 pages (21 pages excluding the appendix and references), 11 figures, 3 tables. Accepted for publication in ApJ

Subjects: astro-ph.HE astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

A subset of ACTIVE GALACTIC NUCLEi (AGN) manifests as compact radio sources with peaked radio spectra, commonly referred to as peaked-spectrum (PS) sources. Generally, PS sources are interpreted as young radio JETs, but the early evolution of the JET is rarely observed and not fully understood. Here, we present VT J182357-234511 (VT J1823-2345), a radio transient in the Very Large Array Sky Survey (VLASS) that resembles a PS source. Notable properties of VT J1823-2345 include: (i) brightening by a factor of 3 between 1996 and 2021 at 1.4 GHz, (ii) peaked spectra with high frequency peaks at $ν_{\mathrm{p,obs}}\gtrsim6\,\mathrm{GHz}$, (iii) a peaked 3 GHz light curve that has been fading since 2023, (iv) a resolved Gaussian (major-axis) size of 0.4 mas in 2024, and (v) a linear POLARIZATION fraction $p_{\mathrm{L}}\simeq0.73\%$ at 8.8 GHz with an extreme Faraday rotation measure $\mathrm{RM_{\mathrm{obs}}} \sim +12,000\,\mathrm{rad}\,\mathrm{m}^{-2}$. On the sky, VT J1823-2345 coincides with a SUPERNOVA remnant and an F-type star, but no background galaxy is seen. Based on the multi-wavelength properties, we disfavor Galactic transients, explosive extragalactic transients, and BLAZAR variability as plausible explanations. We argue that VT J1823-2345 is consistent with a "short-lived" parsec-scale PS source with a decades-old JET that does not grow into a large-scale RADIO GALAXy. From comparing the full VLASS light curves, we speculate that VT J1823-2345 is similar to many VLASS nuclear transients reported in the literature, which may represent an emerging class of transient radio JETs, perhaps related to episodic AGN activity or JETted tidal disruption events.

[abstract 3 / 52] Wow! (score: 8)
arXiv:2610.20580 [pdf, ps, other]

Title: GRB 181201A: Spectropolarimetric Constraints on Prompt Emission and Magnetic Field Structure

Authors: Dhruv S. Bal, Nikita S. Khatiya, Philippe Laurent, Diego Götz, Dieter H. Hartmann, Ramandeep Gill,

Comments: 17 pages, 6 figures (Figure 3: interactive plot), 4 tables, Accepted for publication in the Astrophysical Journal

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Gamma-ray bursts (GRBs) have served as testbeds for high-energy astrophysical phenomena since their discovery over 50 years ago. GRB detections reveal diverse properties across events, complicating efforts to constrain their emission mechanisms, MAGNETic fields, JET structures, and compositions. Spectropolarimetry is a powerful tool utilized to disentangle these properties. INTEGRAL/IBIS has previously detected three polarized GRBs 041219A ($65\pm 26$%), 061122 ($>$33%) and 140206A ($>$28%). We present the time-integrated and time-resolved analyses of the fourth-polarized GRB 181201A. This GRB exhibits high POLARIZATION ($81.5^{+17.2}_{-15.7}$%) over three time bins with the highest signal-to-noise ratio, and the POLARIZATION angle (PA) shows a modest temporal evolution. The photon index does not cross the SYNCHROTRON line-of-death and shows a hard-to-soft evolution. A high degree of POLARIZATION (PD) tends to disfavor a photospheric emission model, as previous studies indicate that this model yields PD $<$ 20%. A modest evolution in the PA points towards a non-axisymmetric JET with a multi-patch emission. Our results indicate that under standard SYNCHROTRON conditions, the MAGNETic field is coherent but lacks global structure. Moreover, the field has multiple patches, but only one or a few dominate due to high degrees of POLARIZATION, which overlap with the intrinsic maximum of SYNCHROTRON emission within 3$σ$ errors. The high PD is also indicative of the Compton Drag scenario, but only under certain conditions, such as viewing the RELATIVISTIC JET near its edge. However, given our error bars and the scope for improvement in our pipeline, we cannot strongly favor either scenario; both may remain viable.

[abstract 4 / 52] Wow! (score: 7)
arXiv:2603.26882 [pdf, ps, other]

Title: Identifying heating processes in simulations with an entropy-based scheme: A single JET episode in a galaxy cluster

Authors: Moun Meenakshi, Rainer Weinberger, Christoph Pfrommer, Thomas Berlok,

Comments: Accepted in A&A. Main text: 17 pages,12 figures

Subjects: astro-ph.HE astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Understanding heating processes in galaxy clusters is essential for predicting the regulation of radiative cooling and STAR FORMATION, and for clarifying the mechanisms underlying ACTIVE GALACTIC NUCLEus (AGN) feedback in cool-core clusters. We investigate the processes through which AGN JETs deposit heat into the intracluster medium (ICM) by tracking passive entropy scalars in MAGNETo-hydrodynamic (MHD) simulations. This enables us to systematically disentangle the contributions from different heating channels. We successfully validate this method with several idealized tests, including turbulent heating, heating by anisotropic Braginskii viscosity, dissipative and adiabatic heating by shocks using in-situ shock-detection methods, and COSMIC RAY (CR) heating through the excitations and damping of Alfvén waves. Using this methodology, we simulate single-epoch outbursts of high-power JETs with varying densities in a cluster environment. Light JETs produce wider bubbles, displacing a larger fraction of the gas in the cluster's core, whereas comparatively denser JETs propagate more efficiently to larger distances without significantly disturbing the central region. During early evolution, shock heating of the ICM prevails irrespective of JET density. At later times, light JETs primarily heat the ICM through turbulently induced heating (which includes dissipation of vortices emerging from a turbulent cascade and mixing gas of different temperatures) and compressible dissipation of sound waves and very weak shocks, while denser JETs continue to dissipate most of their energy via shocks. Particularly, turbulently induced heating by solenoidal-shear motions prevails inside the cocoon, whereas shocks and acoustic compressions dominate outside. In light JETs, the forward shock weakens rapidly, whereas dense JETs can sustain strong bow shocks to large distances.

[abstract 5 / 52] Wow! (score: 7)
arXiv:2610.18972 [pdf, ps, other]

Title: The Second Catalog of Low-Energy FERMI-LAT Sources

Authors: LAT Collaboration,

Comments: Accepted for publication in ApJ Supplements. Contact authors: Lea Marcotulli, Scott Joffre, Christopher Karwin, Benoit Lott, Dario Gasparrini. The full catalog is available at the FSSC: https://fermi.gsfc.nasa.gov/ssc/data/access/lat/2FLE/

Subjects: astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

We used 14 years of FERMI-Large Area Telescope (LAT) data to derive a catalog of sources detected between 20 MeV and 200 MeV. For each source we provide localization, spectral, and association information. The Second Catalog of Low-Energy FERMI-LAT sources (2FLE) contains 450 sources detected at $TS>25$, with median energy flux of $F_{20-200 \, \text{MeV}} = 1.9\times10^{-11}$ erg cm$^{-2}$ s$^{-1}$. Using a Bayesian and likelihood-ratio method, we associate 377 2FLE sources with a known counterpart. Of the 325 objects associated with extragalactic sources, the dominant source class represented in the 2FLE are flat-spectrum radio QUASARs (FSRQ). Additionally, 52 sources are associated with Galactic sources. Three associated sources have not been previously detected in any $γ$-ray catalog and represent new $γ$-ray sources of known origin. We find that 387 2FLE sources have a positional cross-match with the 4FGL-DR4 sources. For the sources with a 4FGL counterpart, we compare the spectrum of the 2FLE source to the 4FGL spectral energy distributions. Of the 73 2FLE sources without multi-wavelength associations, 13 have a 4FGL counterpart that lacks classification, while 60 are newly discovered $γ$-ray sources. Among these 60 sources, 51 are found at high latitudes ($|b|>10^{\circ}$), and 38 are detected at $>10σ$. Additionally, we find that out of the 450 2FLE sources 45 are TeV emitters, and 6 are spatially coincident with a 1LHAASO source. The 2FLE helps us pave the way for reducing the ``MeV gap", and provides the most sensitive catalog between 20-200 MeV to date.

[abstract 6 / 52] Wow! (score: 7)
arXiv:2610.20163 [pdf, ps, other]

Title: Search for High-Energy Neutrinos from Infrared Flares

Authors: R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, J. M. Alameddine, S. Ali, N. M. Amin, K. Andeen, C. Arg{ü}elles, S. Athanasiadou, S. N. Axani, R. Babu, X. Bai, A. Balagopal V., S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, S. Benkel, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, E. Blaufuss, L. Bloom, S. Blot, F. Bontempo, J. Y. Book Motzkin, C. Boscolo Meneguolo, S. B{ö}ser, O. Botner, J. Braun, B. Brinson, Z. Brisson-Tsavoussis, L. Brusa, R. T. Burley, D. Butterfield, K. Carloni, J. Carpio, N. Chau, Y. C. Chen, Z. Chen, D. Chirkin, S. Choi, A. Chubarov, B. A. Clark, D. A. Coloma Borja, A. Connolly, J. M. Conrad, D. F. Cowen, C. De Clercq, J. J. DeLaunay, D. Delgado, T. Delmeulle, S. Deng, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, J. C. D{\'ı}az-V{é}lez, S. DiKerby, T. Ding, M. Dittmer, A. Domi, L. Draper, L. Dueser, D. Durnford, K. Dutta, M. A. DuVernois, T. Ehrhardt, L. Eidenschink, A. Eimer, C. Eldridge, P. Eller, E. Ellinger, D. Els{ä}sser, R. Engel, H. Erpenbeck, W. Esmail, S. Eulig, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. Fattorini, A. R. Fazely, A. Fedynitch, N. Feigl, C. Finley, D. Fox, A. Franckowiak, S. Fukami, P. F{ü}rst, J. Gallagher, A. Garcia, M. Garcia, E. Genton, L. Gerhardt, A. Ghadimi, C. Glaser, T. Gl{ü}senkamp, J. G. Gonzalez, S. Goswami, A. Granados, D. Grant, S. J. Gray, S. Griffin, S. Griswold, K. M. Groth, D. Guevel, C. G{ü}nther, P. Gutjahr, C. Ha, A. Hallgren, F. Halzen, M. Handt, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, J. H{ä}ußler, K. Helbing, J. Hellrung, B. Henke, L. Hennig, F. Henningsen, L. Heuermann, R. Hewett, N. Heyer, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, R. Hmaid, K. D. Hoffman, A. Hollnagel, D. Hooper, S. Hori, K. Hoshina, M. Hostert, W. Hou, M. Hrywniak, T. Huber, K. Hultqvist, K. Hymon, A. Ishihara, W. Iwakiri, M. Jacquart, S. Jain, O. Janik, M. Jansson, M. Jin, N. Kamp, D. Kang, W. Kang, A. Kappes, L. Kardum, T. Karg, A. Karle, A. Katil, M. Kauer, J. L. Kelley, B. Kern, M. Khanal, A. Khatee Zathul, A. Kheirandish, T. Kim, H. Kimku, F. Kirchner, J. Kiryluk, C. Klein, S. R. Klein, Y. Kobayashi, S. Koch, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. K{ö}pke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kowalski, A. Kravka, N. Krieger, T. Krishnan, K. Kruiswijk, E. Krupczak, E. Kun, N. Kurahashi, C. Lagunas Gualda, L. Lallement Arnaud, M. J. Larson, F. Lauber, J. P. Lazar, K. Leonard DeHolton, A. Leszczy{ń}ska, C. Li, J. Liao, C. Lin, Q. R. Liu, Y. T. Liu, M. Liubarska, C. Love, L. Lu, F. Lucarelli, W. Luszczak, Y. Lyu, M. Macdonald, F. Machingal, E. Magnus, Y. Makino, E. Manao, S. Mancina, A. Mand, I. C. Mari{ş}, S. Marka, Z. Marka, I. Martinez-Soler, R. Maruyama, J. Mauro, F. Mayhew, F. McNally, K. Meagher, A. Medina, M. Meier, Y. Merckx, L. Merten, J. M. Mitchell, S. Mondal, T. Montaruli, R. W. Moore, Y. Morii, A. Mosbrugger, D. Mousadi, E. Moyaux, T. Mukherjee, M. Nakos, U. Naumann, R. Neshat, L. Neste, M. Neumann, M. U. Nisa, K. Noda, A. Noell, A. Novikov, A. Obertacke, V. O'Dell, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, B. Owens, V. Palusova, H. Pandya, A. Parenti, C. Parisel, N. Park, V. Parrish, E. N. Paudel, L. Paul, C. P{é}rez de los Heros, T. Pernice, T. C. Petersen, J. Peterson, S. Pick, M. Plum, A. Pont{é}n, V. Poojyam, B. Pries, R. Procter-Murphy, G. T. Przybylski, L. Pyras, C. Raab, J. Rack-Helleis, N. Rad, M. Ravn, K. Rawlins, Z. Rechav, A. Rehman, R. Reimann, I. Reistroffer, E. Resconi, C. D. Rho, W. Rhode, L. Ricca, B. Riedel, A. Rifaie, E. J. Roberts, S. Rodan, M. Rongen, A. Rosted, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, A. Sandrock, G. Sanger-Johnson, M. Santander, S. Sarkar, M. Scarnera, M. Schaufel, H. Schieler, S. Schindler, L. Schlickmann, B. Schl{ü}ter, F. Schl{ü}ter, N. Schmeisser, T. Schmidt, F. Schmitt, A. Scholz, F. G. Schr{ö}der, S. Schwirn, S. Sclafani, D. Seckel, L. Seen, M. Seikh, S. Seunarine, P. A. Sevle Myhr, R. Shah, S. Shah, A. Sharma, S. Shefali, N. Shimizu, M. Shin, R. Singh, B. Skrzypek, R. Snihur, J. Soedingrekso, D. Soldin, P. Soldin, G. Sommani, D. Song, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, T. Stezelberger, T. St{ü}rwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, A. Terliuk, A. Thakuri, P. Thelen, M. Thiesmeyer, W. G. Thompson, J. Thwaites, W. Tian, S. Tilav, K. Tollefson, J. A. Torres, S. Toscano, D. Tosi, K. Upshaw, A. Vaidyanathan, N. Valtonen-Mattila, J. Valverde, J. Vandenbroucke, T. Van Eeden, N. van Eijndhoven, L. Van Rootselaar, J. van Santen, J. Vara, F. Varsi, M. Velazquez, M. Venugopal, M. Vereecken, S. Vergara Carrasco, S. Verpoest, A. Vijai, J. Villarreal, C. Walck, A. Wang, E. H. S. Warrick, C. Weaver, P. Weigel, A. Weindl, J. Weldert, A. Y. Wen, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, L. Witthaus, J. Woodward, G. Wrede, X. W. Xu, J. P. Yanez, Y. Yao, E. Yildizci, S. Yoshida, F. Yu, S. Yu, T. Yuan, S. Yun-C{á}rcamo, A. Zander Jurowitzki, A. Zegarelli, S. Zhang, Z. Zhang, P. Zhelnin, P. Zilberman, C. Zilleruelo Ca{ñ}as, M. Zimmermann,

Comments: 10 pages, 3 figures, To be submitted to Astronomy & Astrophysics

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

IceCube has detected a diffuse flux of high-energy astrophysical neutrinos. While its astrophysical origin is unknown, a significant neutrino emission has been observed from the gamma-ray BLAZAR TXS 0506+056 and the Seyfert galaxy NGC 1068. This suggests accretion by supermassive BLACK HOLEs as one of the candidate mechanisms of the diffuse neutrino flux. Indeed, external studies that made use of IceCube data identified candidate sources, including AT2019dsg, likely a stellar tidal disruption event (TDE), and AT2019fdr, associated with an ACTIVE GALACTIC NUCLEus (AGN). An additional study using an optically detected sample of 63 accretion flares revealed another candidate as a potential high-energy neutrino counterpart: AT2019aalc. All of these candidate transients exhibit strong dust echoes, characterized by delayed infrared (IR) emission relative to the initial optical outburst. We look for correlations between the most comprehensive catalog of infrared flares and 10 years of IceCube archival data. We perform a time-dependent stacking analysis testing 393 sources in the Northern Sky against 10 years of through-going tracks. No significant neutrino emission is observed, and we derive upper limits to constrain neutrino emission from this catalog. These limits are subsequently extrapolated to a population-level study. We find that the contribution of IR flares to the IceCube diffuse neutrino flux at 100 TeV is below 2.7% for a spectral index of 2.5.

[abstract 7 / 52] Yes (score: 6)
arXiv:2608.09395 [pdf, ps, other]

Title: Hyperaccreting Magnetised Neutron Stars inside Rotating Massive Envelopes: Low-Power Jets and Precursor Flares

Authors: Patrick Chi-Kit Cheong, Christopher L. Fryer, David Radice,

Comments: Accepted to PRD

Subjects: astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

The engulfment of a neutron star (NS) by a massive companion initiates a highly dynamic common-envelope (CE) evolution phase. As the NS spirals into the dense stellar core, it is subjected to hypercritical accretion rates that threaten to rapidly collapse the NS into a BLACK HOLE (BH). However, if the infalling envelope possesses sufficient angular momentum and MAGNETic fields, the NS might survive longer and launch feedback-driving JETs. To investigate this, we perform fully coupled, axisymmetric General Relativistic Magnetohydrodynamic (GRMHD) simulations of hyperaccreting NSs, featuring energy-integrated two-moment neutrino transport and a 13-isotope nuclear reaction network. We systematically vary the envelope rotation profile and the MAGNETic field strength of the NS surface ($B_{\rm surf} \sim 5 \times 10^{10} - 5 \times 10^{13}$~G). In non-MAGNETised models, we find that envelope rotation naturally forms a centrifugal barrier and a geometrically thick accretion disk, which suppresses the mass accretion rate and lowers the neutrino luminosity; conversely, the intrinsic spin of the NS has a negligible global impact. In MAGNETised models, the differential rotation of the accretion flow vigorously amplifies the toroidal MAGNETic field via the $Ω$-effect, driving the expansion of MAGNETic towers. Crucially, for strong initial surface MAGNETic fields ($B_{\rm surf} \gtrsim 2.3 \times 10^{13}$~G), the intense MAGNETic pressure could completely halt the accretion flow at the NS surface and evacuates a low-density polar funnel. We conclude that while this highly MAGNETised NS engine successfully delays prompt BH formation and may launch low-power precursor JETs (with powers up to ${\sim} 10^{46}~{\rm erg/s}$) capable of generating observable X-ray flares, it lacks the energy budget to unbind the massive envelope, potentially setting the stage for a subsequent BH-driven explosion.

[abstract 8 / 52] Yes (score: 6)
arXiv:2610.20015 [pdf, ps, other]

Title: Stationary Resistive MHD Solutions Near an Isolated Three-Dimensional Magnetic Null

Authors: Kuljeet Singh Saddal, Dieter H. Nickeler, Rodrigo Meneses Pacheco, Michaela Kraus,

Comments: 22 pages, 6 figures, Accepted for publication in ApJ

Subjects: astro-ph.SR astro-ph.HE physics.plasm-ph physics.space-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Magnetic null points define the MAGNETic field topology in stellar coronae, planetary MAGNETospheres, and astrospheres, and are commonly associated with MAGNETic RECONNECTion. We investigate the local structure of stationary three-dimensional (3D) resistive, incompressible MAGNETohydrodynamic (MHD) flows in the vicinity of an isolated MAGNETic null and an isolated velocity stagnation point, assuming that the two nulls are colocated. The governing MHD equations are solved self-consistently using a first-order local expansion of the MAGNETic and velocity fields about the null. For any given MAGNETic-null configuration, the equations admit a two-parameter family of stationary solutions, comprising multiple solution branches with distinct velocity topologies. Along these families, the velocity-null polarity can change at bifurcation points where the flow becomes effectively 2.5D. A single MAGNETic null can therefore support positive-radial, negative-radial, and spiral stagnation flows, with qualitatively different inflow, outflow, and rotational properties. The associated pressure and resistivity distributions are likewise determined self-consistently and vary across the solution family, demonstrating that they are coupled to the flow topology rather than prescribed independently. The generic solutions do not require the velocity and MAGNETic separatrices to coincide, allowing plasma to cross the MAGNETic fan separatrix and providing a local RECONNECTive flow. These results demonstrate that, in the presence of nonuniform resistivity, the MAGNETic topology alone does not uniquely determine the associated stationary flow, pressure, or resistivity structure around a 3D MAGNETic null, revealing the nonlinear feedback between all macroscopic variables and resistivity. The constant-resistivity field-aligned and spiral field-crossing solutions identified previously are recovered as special cases.

[abstract 9 / 52] Yes (score: 6)
arXiv:2610.20056 [pdf, ps, other]

Title: Flares and flux ropes: an entangled story

Authors: Rony Keppens, Yang Guo, Wenzhi Ruan,

Comments: 11 figures, 33 pages, originally submitted version to Annual Review of Astronomy and Astrophysics (revised and reviewed version is being processed)

Subjects: astro-ph.SR astro-ph.HE physics.plasm-ph physics.space-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Solar flares serve as standard candles for all MAGNETic-RECONNECTion-based energy releases, and their consequences into the heliosphere can be modeled from first principles. This review presents the latest developments in modeling solar flares and their associated flux rope expulsions with state-of-the-art multidimensional MAGNETohydrodynamic (MHD) descriptions. Observationally established ingredients beyond a single-fluid, thermal plasma evolution have been incorporated to varying degrees, and we highlight self-consistent efforts realized in "standard flare" setups.

[abstract 10 / 52] Yes (score: 5)
arXiv:2609.01471 [pdf, ps, other]

Title: A Magnetothermodynamic Theory of Energy Transport In Collisionless Plasmas

Authors: Dominic Payne,

Comments:

Subjects: physics.plasm-ph physics.space-ph

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

Presented here is an exploratory conceptual framework with the aim of describing electroMAGNETic and thermal energy transport and transfer in collisionless plasmas in a coherent way, starting from an arrow-of-time perspective. That is, arguments about the transport of energy are fundamentally based on the idea that systems tend to fill the phase space available to them. First, we describe electric fields, MAGNETic fields, and plasma particles as interacting subsystems that are thermodynamically linked in specific ways. Second, we discuss the importance of the stochastic electric field in the transport of plasma particles down energy density gradients until the energy flux contributions from so-called electrothermodynamic (ETD) interactions become sufficiently uniform. Third, the logic of ETD transport is extended to a MAGNETized system invoking 2 types of MAGNETothermodyamic (MTD) transport: 1) transport of electroMAGNETic energy through stochastic Poynting flux and 2) plasma energy transport through stochastic drift energy fluxes associated with local ExB drift motion. The magnitudes of the ETD and MTD mechanisms are tied to local characteristic scales of the electric field fluctuations and critical scales are derived beyond which ETD mechanisms dominate MTD mechanisms. Finally, we discuss the interplay between electrothermodynamic and MAGNETothermodynamic equilibria (ETE and MTE), dynamics in the small critical scale (MTD) limit, and the potential relevance of this type of description to the problem of RECONNECTion onset and scale coupling.

[abstract 11 / 52] Yes (score: 5)
arXiv:2610.17248 [pdf, ps, other]

Title: Scaling Up: A Global Optical/X-ray Correlation For Reprocessing Across Black Hole Masses

Authors: Changhyun Cho, David M. Russell, Aaryan Sharma, Payaswini Saikia, Maria Cristina Baglio, Kevin Alabarta, Sandeep K. Rout, Yi-Jung Yang, Eleonora Caruso, Mokhine Motsoaledi, Meriana Allah, Ian M. McHardy,

Comments: 31 pages, 4 figures, 2 tables. Submitted to ApJ

Subjects: astro-ph.HE astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

This study extends the optical/X-ray correlation from BLACK HOLE low-mass X-ray binaries (XRBs) to ACTIVE GALACTIC NUCLEi (AGN), bridging scales from stellar-mass to supermassive BLACK HOLEs (SMBHs). In XRBs, optical emission predominantly originates from the thermal reprocessing of high-energy photons on the surface of the geometrically thin, optically thick accretion disk. The reprocessed optical luminosity follows a power-law relation of the form $L_{V} \propto L_{X}^β a$, with $β\sim 0.5$, where $L_X$ is the X-ray luminosity and the orbital separation $a$ serves as a proxy for the disk size. To test the universality of this relationship across all mass scales, we analyzed quasi-simultaneous X-ray and optical flux data from a sample of XRBs and AGN that have estimates of the radius of the optically emitting disk. To bridge the structural differences between these populations, we utilized the characteristic optical/X-ray time lag derived from reverberation mapping as a physical proxy for the reprocessing radius. Our analysis reveals a tight, global correlation across all BLACK HOLE masses, described by $\log L_V = 0.48\log L_X + 0.96\log a_R + 6.5$ with a scatter of $\sim 0.20$ dex, where $a_R$ is the reprocessing radius derived from the lag. Incorporating a geometric correction for the disk inclination angle ($\cos i$) slightly reduces this scatter to $0.18$ dex. These results suggest that X-ray reprocessing is scale-invariant across accretion disks, from stellar-mass BLACK HOLEs to SMBHs. This scaling relation provides new constraints for models of X-ray emission regions in accreting BLACK HOLEs.

[abstract 12 / 52] Yes (score: 5)
arXiv:2610.19126 [pdf, ps, other]

Title: Are Broad Mg II Galaxies Fading AGN?

Authors: Stephanie M. LaMassa, Michael Eracleous, Jessie Runnoe, Benny Trakhtenbrot, Gisella de Rosa,

Comments: ApJ accepted. 32 pages, 23 figures. In the Appendix, we present the results of a PyQSOFit investigation where we vary the number of Monte Carlo samples for error estimation to assess the impact on measurement precision, measurement accuracy, and computing time. The results can serve as a guide for planning the error analysis when decomposing hundreds to thousands of spectra with PyQSOFit

Subjects: astro-ph.GA

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

We analyzed a sample of 494 galaxies from the Sloan Digital Sky Survey (SDSS) I-IV that have unusual properties. They display broadened Mg II $λ$2798 line emission, as would be expected of Type 1 ACTIVE GALACTIC NUCLEi (AGN). However, they have weak or absent broad Balmer lines though broadened Balmer lines often accompany broadened ultraviolet lines in Type 1 AGN spectra. We performed a spectral decomposition of these "broad Mg II galaxies'' to assess whether they can be considered fading AGN. The Balmer lines are more responsive to changes in the AGN continuum than the Mg II line. As the AGN power source fades, broad H$β$ and then H$α$ will weaken and eventually disappear, leaving broad Mg II as a signpost of a more active past. In support of this interpretation, we found that broad Mg II galaxies have weaker AGN luminosities and lower accretion rates (parameterized by the Eddington ratio) than typical Type 1 QUASARs from SDSS. The Eddington ratio of broad Mg II galaxies are similar to dim-state changing-look AGN, with an average value $\lesssim$1\%, which is the threshold at which the inner region of a geometrically thin accretion disk is thought to evaporate and be replaced by a geometrically thick radiatively inefficient accretion flow in stellar-mass BLACK HOLEs. Broad Mg II galaxies may represent the penultimate stage in a changing-look AGN sequence prior to the complete disappearance of all broad lines.

[abstract 13 / 52] Yes (score: 5)
arXiv:2610.19317 [pdf, ps, other]

Title: Deep X-ray View of a Distant Protocluster Anchored by a Quasar at $z=6.63$: No Evidence for Enhanced X-ray AGN Activity

Authors: Shouyi Wang, Feige Wang, Jinyi Yang, Bin Luo, Xiangyu Jin, Fan Zou, Jaclyn B. Champagne, Xiaohui Fan, Elaina Malczewski, Fabio Vito, Xue-Bing Wu, Eduardo Bañados, Fuyan Bian, Thomas Connor, Tiago Costa, Anna-Christina Eilers, Emanuele Paolo Farina, Joseph F. Hennawi, Hyunsung D. Jun, Jiang-Tao Li, Chiara Mazzucchelli, Klaudia Protušová, Fabian Walter, Zhibo Yu, Minghao Yue,

Comments: 32 pages, 12 figures. Accepted for publication in ApJ. The X-ray source catalog and merged images are available at https://zenodo.org/records/21945827

Subjects: astro-ph.GA astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

Whether dense environments accelerate SMBH growth during cosmic reionization remains uncertain because X-ray constraints on $z>6$ protoclusters are rare. We analyze $\sim865$ ks of Chandra observations of J0910-0414 QUASAR field, a massive protocluster at $z=6.63$. We construct a catalog of 251 X-ray sources and search for AGN among 21 spectroscopically confirmed members, excluding the central QUASAR. This is the first systematic X-ray AGN census in a $z>6$ protocluster; none of the members is individually detected. Stacking all members ($\sim17$ Ms total exposure) yields no significant signal and limits the average rest-frame 2-10 keV luminosity to $\langle L_{\rm 2-10~keV}\rangle\leq9.54\times10^{42}~\rm erg~s^{-1}$. The null result gives a central 90% Jeffreys upper bound of $f_{\rm AGN}<0.09$. After accounting for the spatially varying sensitivity, the field Compton-thin X-ray luminosity function predicts $N_{\rm exp,field}=0.0356$ AGN in the surveyed volume. Assuming the overdensity profile of AGNs in this protocluster is the same as that of galaxies determined by Wang et al. (2024), the expected AGN count becomes $N_{\rm exp}=0.131$. Zero detections then imply a one-sided 90% upper limit of $η_{\rm rel}<17.5$ on any additional X-ray AGN enhancement beyond that associated with the galaxy overdensity. Although $η_{\rm rel}<17.5$ permits more than an order-of-magnitude enhancement, the data show no significant excess of X-ray-detectable AGN in J0910-0414 protocluster. The present X-ray data may miss heavily obscured, intrinsically X-ray-weak, or intermittently accreting SMBHs; the non-detection therefore does not rule out AGNs among the member galaxies.

[abstract 14 / 52] Yes (score: 5)
arXiv:2610.19348 [pdf, ps, other]

Title: Magnetic Reconnection Governs the Entire Lifecycle of Solar Eruptive Magnetic Flux Rope

Authors: Xinkai Bian, Chaowei Jiang, Qingjun Liu, Xueshang Feng, Pingbing Zuo, Yi Wang,

Comments: 15 pages, 7 figures

Subjects: astro-ph.SR physics.plasm-ph physics.space-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

While MAGNETic flux ropes (MFRs) are widely accepted to exist prior to many solar eruptions, the physical mechanism responsible for triggering and subsequently driving their eruptions remains debated. Classical models commonly attribute eruption onset to ideal MAGNETohydrodynamic instabilities, particularly the torus instability, while MAGNETic RECONNECTion is often regarded as a secondary process. Using high-resolution three-dimensional MHD simulations, we investigate the eruption of an MFR that forms self-consistently through flux cancellation driven by converging motions and photospheric diffusion following an initial shearing phase. The pre-eruption MFR rises quasi-statically and reaches a height where the decay index exceeds the classical torus instability threshold, yet the system continues to evolve quasi-statically without eruption. Instead, eruption begins only when the current sheet beneath the MFR becomes sufficiently thin for MAGNETic RECONNECTion to set in. Increasing numerical resolution systematically delays the eruption onset, whereas the decay index at eruption onset remains nearly unchanged, demonstrating that the onset is governed by RECONNECTion rather than torus instability. During the eruption, MAGNETic RECONNECTion continuously converts surrounding sheared arcades into newly RECONNECTed twisted flux that merges with the pre-eruption MFR and continuously to build the erupting MFR. A component-resolved analysis of the Lorentz force work further shows that the newly RECONNECTion flux contributes predominantly to the main acceleration phase. These results demonstrate that MAGNETic RECONNECTion plays a central role throughout the entire lifecycle of the eruptive MFR: it builds the MFR, directly triggers its eruption, and provides the dominant driving of the eruption.

[abstract 15 / 52] Yes (score: 5)
arXiv:2610.20546 [pdf, ps, other]

Title: Dynamics of a switchback-like MAGNETic deflection induced by a propagating coronal JET

Authors: Jade Touresse, Etienne Pariat, Clara Froment, Peter F. Wyper,

Comments: 18 pages, 10 figures, accepted for publication in Astronomy and Astrophysics

Subjects: astro-ph.SR

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Parker Solar Probe (PSP) revealed the ubiquity of switchbacks (SBs), sharp, localised MAGNETic deflections in the nascent solar wind, renewing interest in their origin. One proposed mechanism involves solar JETs: collimated, impulsive features driven by MAGNETic RECONNECTion that launch Alfvénic torsional wavefronts into the heliosphere. We test whether realistic spacecraft sampling of a propagating solar JET produces in-situ signatures consistent with PSP observations. We also examine the 3D MAGNETic topology of the resulting structures and how deflection amplitudes evolve with the ambient plasma environment. We perform a 3D MAGNETohydrodynamic simulation of a solar JET in the ambient solar wind, embedding a virtual spacecraft trajectory based on PSP's actual 22nd-perihelion orbit to generate synthetic measurements. The simulation reproduces SB-like signatures with durations and profiles consistent with PSP observations, confirming earlier results from simplified trajectories. We visualise the fully 3D MAGNETic topology of a JET-driven SB region, identifying two field-line families: one with a single deflection and another with two sequential deflections along the same field line. Both are outward-propagating Alfvénic structures. Deflection amplitudes depend strongly on background plasma $β$, increasing substantially in low-$β$ regions and evolving more moderately where $β\sim 1$. These results show that solar JETs can produce Alfvénic, SB-like structures along realistic spacecraft trajectories. Their topology is inherently 3D and structurally diverse, and their evolution depends on ambient plasma $β$. Complete MAGNETic reversals would require longer residence times in low-$β$ environments. Our findings support a solar origin for a fraction of SBs and constrain interpretations of their underlying MAGNETic structure.

[abstract 16 / 52] Yes (score: 4)
arXiv:2604.01196 [pdf, ps, other]

Title: Delayed Radio Flares in Neutrino-associated Blazars: The Case of TXS 0506+056

Authors: S. I. Stathopoulos, C. Yuan, G. Vasilopoulos, F. Testagrossa, D. Karavola, M. Petropoulou, W. Winter,

Comments: Revised version incorporating referee comments, accepted for publication in ApJL

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Radio flares have been postulated to be associated with the production of astrophysical neutrinos. For example, TXS 0506+056 exhibits a 2-3 yr delay between the 2017 IceCube-170922A/gamma-ray flare and a GHz radio maximum. We quantitatively test if the delayed radio flare originates from the same compact region where neutrinos and gamma-rays are produced as it expands downstream and SYNCHROTRON self-absorption (SSA) is reduced. Starting from the 2017 flare blob parameters, we model the expanding production region and its evolving radio emission with LeHaMoC in a fully time-dependent framework, and compare our 1.2-22 GHz light curves to RATAN-600 data. We study different scenarios with increasing levels of sophistication, including continuous injection and energy re-dissipation on pc scales. While a simple expanding blob scenario fails to reproduce the radio data, a downstream dissipation episode of particles in the optically thin regime, followed by JET deceleration, successfully describes the radio evolution. The radio flare is powered by leptonic SYNCHROTRON emission and is largely insensitive to the proton population relevant for neutrino production, implying that the delayed radio flare mainly probes downstream dissipation and beaming in certain JET configurations instead of being a direct radiative counterpart of the compact neutrino-production zone.

[abstract 17 / 52] Yes (score: 4)
arXiv:2608.18287 [pdf, ps, other]

Title: Continuum Variability in AGN: Evidence for Systematically Suppressed Fluctuations in the BAL Population

Authors: A. Aliaga, P. Arévalo, M. L. Martínez-Aldama, W. Zuo, B. Muñoz-Bravo,

Comments: Accepted for publication in A&A

Subjects: astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We aim to compare the flux variability of Broad Absorption Line QUASARs (BAL) to non-BAL QUASARs, controlling for BLACK HOLE parameters to inform models concerning the generation of the BAL phenomenon. Using SDSS DR16 and ZTF $g$- and $r$-band light curves, we select QUASARs with $1.57 \leq z \leq 2.00$ and $18.5 \leq rmag \leq 19.8$. This redshift range ensures that the $g$-band covers the C IV emission line (and trough in BALs) while the $r$-band probes continuum variability, and allows BLACK HOLE mass (MBH) estimates via Mg II. We quantify variability using excess variance and damped random walk (DRW) parameters ($σ_{\mathrm{DRW}}$, $τ_{\mathrm{DRW}}$). We also compared the DRW metrics in bins of MBH and Eddington ratio (REdd) to isolate the influence of the BAL phenomenon in objects with the same physical properties. Excess variance and $σ_{\mathrm{DRW}}$ are consistently smaller for BALs, confirming lower long-term variability, while the $g$-band exhibits higher variability than the $r$-band across both populations. These differences persist in fixed bins of MBH and REdd, indicating that the suppressed variability in BALs is not simply driven by differences in these properties between BAL and non-BAL samples. These results show that BAL QUASARs are systematically less variable than non-BAL QUASARs in both bands, confirming that this suppression is an intrinsic feature of the continuum rather than an effect of emission or absorption line contamination. The samples could be made to agree if BAL MBH values were systematically overestimated by a factor $\gtrsim 4$, implying a significantly higher REdd. Alternatively, the lower variability in BALs can be related to their lower X-ray luminosities, or to significant nuclear obscuration, if the inner part of the accretion disc were more obscured in BALs and more variable than the rest of the disc.

[abstract 18 / 52] Yes (score: 4)
arXiv:2610.19877 [pdf, ps, other]

Title: Linear Polarization of Synchrotron Radiation from Very-small-pitch-angle Electrons

Authors: Meng Nie, Jirong Mao,

Comments: 23 pages, 12 figures. Accepted for publication in ApJ

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

For SYNCHROTRON radiation with pitch angle $α\ll 1/γ$ where $γ$ is the electron Lorentz factor, referred to as very-small-pitch-angle SYNCHROTRON radiation, the POLARIZATION properties differ significantly from those of conventional SYNCHROTRON radiation ($α\gg 1/γ$). In this work, we investigate the linear POLARIZATION characteristics of very-small-pitch-angle SYNCHROTRON radiation from RELATIVISTIC thermal and nonthermal electrons. We calculate the linear POLARIZATION by applying power-law and Maxwellian electron energy distributions. Moreover, some SYNCHROTRON sources exhibit a hybrid distribution of nonthermal and thermal electrons, and we also calculate the POLARIZATION degree for a hybrid electron energy distribution. The calculations are performed in the radio, optical, X-ray, and $γ$-ray bands. Our results show that the linear POLARIZATION degree of very-small-pitch-angle SYNCHROTRON radiation is generally lower than that of conventional SYNCHROTRON radiation. Very-small-pitch-angle SYNCHROTRON radiation from both nonthermal and thermal electrons can produce significant linear POLARIZATION. However, the POLARIZATION exhibits diverse behaviors across different physical parameters. The general scenario provided in this work can be considered for the application to all kinds of SYNCHROTRON sources, as we suggest that the very-small-pitch-angle case is crucial for the study of SYNCHROTRON POLARIZATION.

[abstract 19 / 52] Yes (score: 4)
arXiv:2610.19879 [pdf, ps, other]

Title: Black Hole Binary Mergers in Galactic Nuclei: Combined Effects of Secular Dynamics and Stellar Flybys

Authors: Hao Wang, Bin Liu, Johan Samsing,

Comments: 18 pages, 5 figures, accepted for publication in ApJ

Subjects: astro-ph.HE astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Galactic nuclei, with the central supermassive BLACK HOLEs (SMBHs) and surrounding dense star clusters, serve as natural laboratories for studying gravitational dynamics in extreme gravitational environments. In this work, we model the long term evolution of BLACK HOLE binaries (BHBs) in these environments by incorporating the tidal influence of the central SMBH, the potential of the nuclear star cluster, SMBH induced RELATIVISTIC precession, and stochastic perturbations from stellar flybys. Our numerical simulations show that the long term evolution of BHBs is predominantly governed by the SMBH-driven ZLK mechanism. However, once stellar flybys are included, they can modify both the binary angular momentum and energy. The cumulative effect of repeated flyby encounters substantially reshapes the long term dynamical evolution, eventually leading systems toward either merger or disruption. Based on a population synthesis study, we find that this combined secular and non-secular channel produces a merger rate of approximately $\mathcal{R}\simeq16\mathrm{Gpc^{-3}yr^{-1}}$, which is significantly higher than the rates predicted by dynamical channels that neglect stellar flybys. Furthermore, we predict that a non-negligible fraction of merging systems would retain detectable eccentricities at low frequencies around 5 Hz, thus providing a distinctive observational signature for next generation ground based GW detectors. Our results demonstrate that the stochastic perturbations from the surrounding environment are essential for modeling BHB evolution in galactic nuclei, and that this channel may contribute a major fraction of observed mergers.

[abstract 20 / 52] Yes (score: 4)
arXiv:2610.20276 [pdf, ps, other]

Title: Search for Compact Binary Coalescences with Sub-solar Mass Components in Data from the Second Part of LIGO-Virgo-KAGRA's Fourth Observing Run

Authors: The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, A. G. Abac, A. Abe, I. Abouelfettouh, F. Acernese, K. Ackley, A. Adam, S. Adhicary, D. Adhikari, R. X. Adhikari, V. K. Adkins, S. Afroz, A. Agapito, D. Agarwal, M. Agathos, N. Aggarwal, S. Aggarwal, O. D. Aguiar, I. -L. Ahrend, L. Aiello, A. Ain, P. Ajith, T. Akutsu, L. Albers, W. Ali, S. Al-Kershi, C. Allan, C. Allene, A. Allocca, S. Al-Shammari, J. A. Alvarez, S. Alvarez-Lopez, W. Amar, O. Amarasinghe, A. Amato, F. Amicucci, C. Amra, A. B. Anand, C. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, M. Andia, M. Ando, F. Andrade-Oliveira, M. Andrés-Carcasona, J. L. Andrey, T. Andrić, J. Anglin, J. Anna, J. M. Antelis, S. Antier, T. Aoki, M. Aoumi, E. Z. Appavuravther, E. A. Appelt, S. Appert, S. K. Apple, K. Arai, A. Araya, M. C. Araya, M. Arca Sedda, F. Arciprete, J. S. Areeda, N. Aritomi, F. Armato, S. Armstrong, N. Arnaud, M. Arogeti, S. M. Aronson, G. Ashton, Y. Aso, L. Asprea, M. Assiduo, S. Assis de Souza Melo, S. M. Aston, P. Astone, P. S. Aswathi, F. Attadio, F. Aubin, K. AultONeal, G. Avallone, N. Avdeev, E. A. Avila, S. Babak, C. Badger, S. Bae, S. Bagnasco, S. Baimukhametova, L. Baiotti, T. Baka, K. A. Baker, T. Baker, G. Balbi, G. Baldi, N. Baldicchi, M. Ball, G. Ballardin, M. Ballelli, S. W. Ballmer, S. Banagiri, B. Banerjee, D. Bankar, T. M. Baptiste, P. Baral, M. Baratti, J. C. Barayoga, K. Baric, B. C. Barish, D. Barker, D. Barman, N. Barman, F. Barone, B. Barr, M. Barrios, L. Barsotti, M. Barsuglia, D. Barta, M. A. Barton, I. Bartos, A. Basalaev, R. Bassiri, A. Basti, M. Bawaj, J. C. Bayley, A. C. Baylor, P. A. Baynard, M. Bazzan, V. M. Bedakihale, F. Beirnaert, M. Bejger, A. S. Bell, C. Bellani, D. S. Bellie, D. Beltran-Martinez, E. Benedetti, W. Benoit, I. Bentara, M. Ben Yaala, S. Bera, F. Bergamin, B. K. Berger, M. Beroiz, C. P. L. Berry, I. Berry, D. Bersanetti, T. Bertheas, A. Bertolini, J. Betzwieser, D. Beveridge, N. Bevins, J. Bezerra-Sobrinho, R. Bhandare, R. Bhatt, A. Bhattacharjee, D. Bhattacharjee, S. Bhattacharyya, S. Bhaumik, V. Biancalana, F. Bianchi, I. A. Bilenko, M. Bilicki, G. Billingsley, A. Binetti, S. Bini, S. Biot, O. Birnholtz, S. Biscoveanu, A. Bisht, M. Bitossi, M. -A. Bizouard, S. Blaber, J. Black, J. K. Blackburn, L. A. Blagg, C. D. Blair, D. G. Blair, M. Bloch, N. Bode, N. Boettner, P. Bogdan, G. Boileau, M. Boldrini, G. N. Bolingbroke, L. D. Bonavena, V. A. Bonhomme, E. Bonilla, M. S. Bonilla, A. Bonino, R. Bonnand, A. Borchers, N. Borghi, V. Boschi, S. Bose, V. Bossilkov, Y. Bothra, A. Boudon, T. D. Boybeyi, M. Boyle, A. Bozzi, C. Bradaschia, M. J. Brady, P. R. Brady, A. Branch, M. Branchesi, T. Briant, A. Brillet, M. Brinkmann, P. Brockill, E. Brockmueller, A. F. Brooks, D. D. Brown, M. L. Brozzetti, S. Brunett, G. Bruno, R. Bruntz, J. Bryant, Y. Bu, F. Bucci, A. Buchicchio, A. Buggiani, O. Bulashenko, T. Bulik, H. J. Bulten, A. Buonanno, K. Burtnyk, R. Buscicchio, N. Busdon, D. Buskulic, R. L. Byer, R. Cabrita, V. A. Cáceres-Barbosa, L. Cadonati, G. Cagnoli, C. Cahillane, A. Calafat, J. Calderón Bustillo, J. D. Callaghan, T. A. Callister, E. Calloni, S. R. Callos, K. Cannon, V. Cantory, H. Cao, L. A. Capistran, E. Capocasa, G. Capoccia, E. Capote, C. Capuano, G. Capurri, F. Carbognani, K. J. Cardona-Martínez, M. Carlassara, M. Carpinelli, G. Carrillo, G. Carullo, A. Casallas-Lagos, J. Casanueva Diaz, C. Casentini, S. Caudill, M. Cavaglià, R. Cavalieri, A. Ceja, G. Cella, P. Cerdá-Durán, N. Chabbra, W. Chaibi, A. Chakraborty, P. Chakraborty, S. Chakraborty, S. Chalathadka Subrahmanya, C. Chan, J. C. L. Chan, M. Chan, C. -Y. Chang, K. Chang, S. Chao, P. Charlton, E. Chassande-Mottin, C. Chatterjee, Debarati Chatterjee, Deep Chatterjee, M. Chaturvedi, S. Chaty, A. Chen, A. H. -Y. Chen, D. Chen, H. Chen, H. Y. Chen, S. Chen, Yanbei Chen, Yiwen Chen, G. Cheng, H. P. Cheng, P. Chessa, T. Cheunchitra, H. T. Cheung, S. Y. Cheung, F. Chiadini, G. Chiarini, A. Chiba, A. Chincarini, D. Chintala, A. Chiummo, A. Chopra, C. Chou, S. Choudhary, N. Christensen, Y. K. Chu, S. S. Y. Chua, G. Ciani, P. Ciecielag, M. Cieślar, M. Cifaldi, B. Cirok, F. Clara, J. A. Clark, T. A. Clarke, A. Claveus, M. R. Claypool, S. Clesse, F. Cleva, S. M. Clyne, E. Coccia, E. Codazzo, P. -F. Cohadon, D. E. Cohen, E. Colangeli, O. Cole, M. Colleoni, C. G. Collette, J. Collins, S. Colloms, A. Colombo, G. Compère, C. M. Compton, G. Connolly, L. Conti, T. R. Corbitt, I. Cordero-Carrión, S. Corezzi, N. J. Cornish, A. Corsi, S. Cortese, L. A. Corubolo, L. Cotnoir, R. Cottingham, J. A. Cotturone, M. W. Coughlin, P. Couvares, R. Coyne, A. Cozzumbo, J. D. E. Creighton, T. D. Creighton, S. Crook, R. Crouch, J. Csizmazia, K. Csukás, T. J. Cullen, A. Cumming, E. Cuoco, M. Cusinato, R. R. Cuzinatto, L. V. da Conceição, T. Dal Canton, S. Dall'Osso, S. Dal Pra, G. Dálya, Y. Dang, B. D'Angelo, S. Danilishin, O. Danner, S. D'Antonio, K. Danzmann, K. E. Darroch, L. P. Dartez, R. Das, S. Das, A. Dasgupta, V. Dattilo, A. Daumas, I. Dave, A. Davenport, T. F. Davies, D. Davis, M. C. Davis, P. Davis, E. J. Daw, M. Dax, J. De Bolle, E. deBruin, M. Deenadayalan, J. Degallaix, U. Deka, M. De Laurentis, C. J. Delgado Mendez, F. De Lillo, S. Della Torre, W. Del Pozzo, O. M. del Rio, A. Demagny, F. De Marco, G. Demasi, F. De Matteis, C. de Melo, N. Demos, T. Dent, A. Depasse, N. DePergola, R. De Pietri, R. De Rosa, C. De Rossi, E. K. Derrick, M. Desai, D. DeSantis, S. Deshmukh, V. Deshmukh, R. De Simone, S. Determan, S. Dhage, A. Dhani, R. Dhatri, R. Dhurkunde, R. Diab, C. Diaz, M. C. Díaz, F. Diaz Guerra, M. Di Cesare, M. A. Dicorato, T. Dietrich, C. Di Fronzo, M. Di Giovanni, D. Diksha, J. Ding, S. Di Pace, I. Di Palma, D. Di Piero, F. Di Renzo, Divyajyoti, A. Dmitriev, J. P. Docherty, Z. Doctor, N. Doerksen, E. Dohmen, A. Doke, A. Domiciano De Souza, L. D'Onofrio, F. Donovan, K. L. Dooley, S. Doravari, O. Dorosh, F. Dosopoulou, M. Drago, J. C. Driggers, M. Dubois, R. S. Dumbreck, U. Dupletsa, D. D'Urso, P. Dutta Roy, H. Duval, S. Dwivedi, S. E. Dwyer, C. Eassa, M. Eberhardt, M. Ebersold, M. Ebiri, G. Eddolls, A. Effler, J. Eichholz, H. Einsle, M. Eisenmann, M. Emma, K. Endo, R. Enficiaud, V. Ernst, L. Errico, R. Espinosa, M. Esposito, R. C. Essick, H. Estellés, T. Etzel, M. Evans, T. Evstafyeva, J. M. Ezquiaga, F. Fabrizi, V. Fafone, S. Fairhurst, X. Fan, A. M. Farah, B. Farr, W. M. Farr, M. Favata, M. Fays, M. Fazio, J. Feicht, M. M. Fejer, J. -N. Feldhusen, E. Fenyvesi, A. Feo, J. Fernandes, T. Fernandes, G. Fernández Rodríguez, D. Fernando, S. Ferraiuolo, T. A. Ferreira, M. Ferrer-Martinez, F. Fidecaro, P. Figura, I. Fiori, M. Fishbach, R. P. Fisher, S. K. Fitzgerald, V. Fiumara, R. Flaminio, B. Flanagan, S. M. Fleischer, L. S. Fleming, F. Flocco, E. Floden, H. Fong, J. A. Font, F. Fontinele-Nunes, C. Foo, B. Fornal, P. W. F. Forsyth, A. Fragkos, N. Franchini, A. Franco-Ordovas, F. Frappez, F. Frasconi, J. P. Freed, Z. Frei, A. Freise, O. Freitas, R. Frey, W. Frischhertz, P. Fritschel, V. V. Frolov, M. Fuentes-Garcia, R. Fujii, T. Fujimori, Y. Fujiwara, P. Fulda, M. Fyffe, B. U. Gadre, J. R. Gair, S. Galaudage, V. Galdi, M. Galimberti, A. Gamboa, S. Gamoji, A. Ganguly, B. Garaventa, P. García Abia, J. García-Bellido, C. García-Quirós, J. W. Gardner, S. Garg, J. Gargiulo, X. Garrido, A. Garron, F. Garufi, P. A. Garver, C. Gasbarra, F. Gautier, V. Gayathri, T. Gayer, G. Gemme, A. Gennai, V. Gennari, J. George, R. George, O. Gerberding, L. Gergely, A. Ghinassi, Archisman Ghosh, Sayantan Ghosh, Shaon Ghosh, Shrobana Ghosh, Suprovo Ghosh, Tathagata Ghosh, J. A. Giaime, K. D. Giardina, D. R. Gibson, C. Gier, F. Gittins, J. Glanzer, F. Glotin, E. Glowacki, J. Godfrey, R. V. Godley, O. Godwin, A. S. Goettel, E. Goetz, J. Golomb, S. Gomez Lopez, G. González, P. Goodarzi, S. R. Goode, A. Goodwin-Jones, M. Gosselin, S. M. Goss-Grubbs, C. Gostiaux, R. Gouaty, D. W. Gould, D. Goupilliere, K. Govorkova, A. Grado, V. Graham, A. E. Granados, M. Granata, V. Granata, S. Gras, P. Grassia, C. Gray, R. Gray, G. Greco, A. C. Green, L. Green, S. R. Green, A. M. Gretarsson, E. M. Gretarsson, D. Griffith, C. Grimaud, H. Grote, S. Grunewald, A. G. Guerrero, G. M. Guidi, T. Guidry, H. K. Gulati, F. Gulminelli, H. Guo, W. Guo, Y. Guo, A. Gupta, I. Gupta, N. C. Gupta, S. K. Gupta, V. Gupta, N. Gupte, N. Guttman, F. Guzman, M. Haberland, S. Haino, E. D. Hall, E. Z. Hamilton, G. Hammond, W. -B. Han, M. Haney, J. Hanks, C. Hanna, M. D. Hannam, O. A. Hannuksela, H. Hansen, J. Hanson, R. Harada, A. R. Hardison, S. Harikumar, K. Haris, I. Harley-Trochimczyk, J. Harms, G. M. Harry, I. W. Harry, M. T. Hartman, B. Haskell, C. -J. Haster, K. Haughian, H. Hayakawa, K. Hayama, J. Hedberg, A. Heffernan, D. Hegde, M. C. Heintze, J. Heinzel, H. Heitmann, F. Hellman, A. F. Helmling-Cornell, G. Hemming, O. Henderson-Sapir, M. Hendry, I. S. Heng, M. H. Hennig, C. Henshaw, A. Heranval, M. Heurs, A. L. Hewitt, J. Heynen, J. Heyns, S. Hido, S. Hild, M. Hill, S. Hill, Y. Himemoto, C. Hirose, D. Hofman, N. A. Holland, K. Holley-Bockelmann, I. J. Hollows, D. E. Holz, L. Honet, K. M. Hoops, M. E. Hoque, D. J. Horton-Bailey, J. Hough, S. Hourihane, N. T. Howard, E. J. Howell, C. G. Hoy, P. Hsi, H. -Y. Hsieh, C. Hsiung, S. -H. Hsu, W. -F. Hsu, H. Y. Huang, Y. Huang, A. D. Huddart, B. Hughey, D. C. Y. Hui, S. Husa, L. Iampieri, G. A. Iandolo, M. Ianni, Y. Ichinose, K. Ide, R. Iden, A. Ierardi, S. Ikeda, H. Imafuku, K. Imai, G. Inguglia, Y. Inoue, P. Iosif, J. Irwin, K. Ishida, R. Ishikawa, T. Ishikawa, H. Ishino, M. Isi, K. S. Isleif, Y. Itoh, S. Iwaguchi, M. M. Iwaya, B. R. Iyer, C. Jacquet, T. Jacquot, S. J. Jadhav, S. P. Jadhav, K. Jain, A. L. James, K. Jani, S. Jani, J. Janquart, N. N. Janthalur, S. Jaraba, P. Jaranowski, R. Jaume, W. Javed, M. Jensen, W. Jia, J. Jiang, H. -B. Jin, S. -J. Jin, G. R. Johns, N. A. Johnson, M. C. Johnston, R. Johnston, N. Johny, D. H. Jones, D. I. Jones, R. Jones, P. Joshi, S. K. Joshi, G. Joubert, J. Ju, L. Ju, I. L. Juarez-Reyes, K. Jung, H. B. Kabagoz, B. Kacskovics, T. Kajita, I. Kaku, V. Kalogera, M. Kalomenopoulos, M. Kamiizumi, N. Kanda, S. Kandhasamy, G. Kang, J. B. Kanner, S. J. Kapadia, D. P. Kapasi, A. Karia, A. S. Karia, R. Kashyap, M. Kasprzack, H. Kato, T. Kato, E. Katsavounidis, W. Katzman, R. Kaushik, K. Kawabe, S. Kawamura, D. Keitel, S. A. Kemper, L. J. Kemperman, J. Kennington, R. Kesharwani, J. S. Key, R. Khadela, S. S. Khadkikar, F. Y. Khalili, C. Khamar, F. Khan, M. Khursheed, N. M. Khusid, W. Kiendrebeogo, C. Kim, G. Kim, J. C. Kim, K. Kim, M. H. Kim, S. Kim, Y. -M. Kim, C. Kimball, K. Kimes, M. Kinnear, J. S. Kissel, S. Klimenko, A. M. Knee, N. Knust, K. Kobayashi, S. M. Koehlenbeck, K. Kohri, K. Kokeyama, S. Koley, P. Kolitsidou, A. E. Koloniari, K. Komori, K. Kompanets, A. K. H. Kong, A. Kontos, K. Kopczuk, L. M. Koponen, M. Korobko, X. Kou, N. Kouvatsos, T. Koyama, D. B. Kozak, E. Kraja, S. L. Kranzhoff, V. Kringel, N. V. Krishnendu, S. Kroker, A. Królak, K. Kruska, J. Kubisz, K. Kubota, G. Kuehn, D. Kukla, A. Kulur Ramamohan, Achal Kumar, Anil Kumar, Dhruv Kumar, Praveen Kumar, Prayush Kumar, Rahul Kumar, Rakesh Kumar, Ravi Kumar, Sumit Kumar, J. Kume, K. Kuns, N. Kuntimaddi, S. Kuroyanagi, K. Kwak, K. Kwan, S. Kwon, G. Lacaille, D. Laghi, A. H. Laity, N. Lajili, A. Lakhal, E. Lalande, M. Lalleman, S. Lalvani, M. Landry, R. N. Lang, A. Lange, J. A. Lange, R. Langgin, B. Lantz, I. La Rosa, O. Laske, P. D. Lasky, L. Lavezzi, J. Lawrence, M. Laxen, A. Lazzarini, C. Lazzaro, P. Leaci, L. Leali, Y. K. Lecoeuche, H. W. Lee, J. Lee, K. Lee, R. -K. Lee, R. Lee, Sungho Lee, Sunjae Lee, W. Lee, Y. Lee, F. Legger, I. N. Legred, J. Lehmann, L. Lehner, M. Le Jean, A. Lema{î}tre, R. Lemrani Alaoui, M. Lenti, M. Leonardi, M. Lequime, M. Lesovsky, N. Letendre, M. Lethuillier, Y. Levin, S. Lexmond, K. Leyde, A. K. Y. Li, K. L. Li, T. G. F. Li, X. Li, Y. Li, Z. Li, Q. Liang, C-Y. Lin, E. T. Lin, F. Lin, L. C. -C. Lin, Y. -C. Lin, C. Lindsay, S. D. Linker, A. Liu, F. Liu, G. C. Liu, Jian Liu, S. Liu, F. Llamas Villarreal, J. Llobera-Querol, R. K. L. Lo, J. -P. Locquet, S. C. G. Loggins, L. T. London, A. Longo, M. Lopez Portilla, A. Lorenzo-Medina, V. Loriette, M. Lormand, M. Lorusso, G. Losurdo, T. P. Lott, J. D. Lough, H. A. Loughlin, C. O. Lousto, N. K. Y. Low, N. Lu, H. Lück, O. Lukina, D. Lumaca, A. P. Lundgren, L. Lunghini, A. W. Lussier, L. -T. Ma, X. Ma, M. Ma'arif, S. MacBride, K. Machida, D. M. Macleod, I. A. O. MacMillan, A. Macquet, S. S. Madekar, S. Maenaut, S. S. Magare, R. M. Magee, E. Maggio, M. Magnozzi, P. Mahapatra, M. Mahesh, S. Majhi, E. Majorana, C. N. Makarem, E. Makelele, N. Malagon, D. Malakar, J. A. Malaquias-Reis, U. Mali, S. Maliakal, A. Malik, L. Mallick, A. -K. Malz, N. Man, M. Mancarella, V. Mandic, V. Mangano, Z. Mangi, B. Mannix, G. L. Mansell, M. Manske, M. Mantovani, M. Mapelli, S. Marchetti, F. Marion, J. Mark, A. S. Markosyan, J. Markus, E. Maros, S. Marsat, F. Martelli, I. W. Martin, R. M. Martin, B. B. Martinez, M. Martinez, V. Martinez, A. Martini, Juan Carlos Martins, Julio C. Martins, D. V. Martynov, E. J. Marx, L. Massaro, A. Masserot, M. Masso-Reid, T. Masters, S. Mastrogiovanni, G. Mastropasqua, M. Matiushechkina, A. Matte-Landry, L. Maurin, N. Mavalvala, N. Maxwell, A. McCann, G. McCarrol, R. McCarthy, D. E. McClelland, S. McCormick, L. McCuller, L. I. McDermott, C. McElhenny, G. I. McGhee, K. B. M. McGowan, J. McIver, A. McLeod, I. McMahon, T. McRae, R. McTeague, K. McWhirter, D. Meacher, B. N. Meagher, R. Mechum, L. G. Medeiros, R. M. Mehta, A. Melatos, C. S. Menoni, R. A. Mercer, L. Mereni, K. Merfeld, E. L. Merilh, J. R. Mérou, C. Messick, M. Meyer-Conde, F. Meylahn, H. Miao, C. Michel, Y. Michimura, H. Middleton, D. P. Mihaylov, S. J. Miller, M. Millhouse, E. Milotti, V. Milotti, E. Minakaki, Y. Minenkov, Ll. M. Mir, L. Mirasola, C. -A. Miritescu, A. Mishra, C. Mishra, T. Mishra, A. Mitchell, J. G. Mitchell, O. Mitchem, S. Mitra, V. P. Mitrofanov, K. Mitsuhashi, R. Mittleman, O. Miyakawa, S. Miyoki, G. Mo, L. Mobilia, S. R. P. Mohapatra, M. Molina-Ruiz, M. Mondin, M. Montani, G. Montefusco, C. J. Moore, D. Moraru, A. More, S. More, C. Moreno, E. A. Moreno, G. Moreno, A. Moreso Serra, C. Morgan, S. Morisaki, S. Moriwaki, Y. Moriwaki, G. Morras, A. Moscatello, M. Mould, B. Mours, C. M. Mow-Lowry, L. Muccillo, F. Muciaccia, Arunava Mukherjee, D. Mukherjee, Samanwaya Mukherjee, Soma Mukherjee, Subroto Mukherjee, Suvodip Mukherjee, N. Mukund, A. Mullavey, C. L. Mungioli, Y. Murakami, M. Murakoshi, P. G. Murray, D. Nabari, S. Nadji, A. Nagar, N. Nagarajan, K. Nakagaki, A. Nakamura, K. Nakamura, H. Nakano, M. Nakano, D. Nanadoumgar-Lacroze, D. Nandi, V. Napolano, S. U. Naqvi, P. Narayan, A. Nardecchia, I. Nardecchia, T. Narikawa, H. Narola, L. Naticchioni, R. K. Nayak, J. Neeson, L. Negri, A. Nela, C. Nelle, A. Nelson, T. J. N. Nelson, A. Nemmani, A. Neunzert, M. Newell, S. Ng, T. C. K. Ng, L. -A. T. Nguyen, T. T. Nguyen, L. Nguyen Quynh, A. B. Nielsen, Y. Nishino, A. Nishizawa, S. Nissanke, W. Niu, F. Nocera, J. Noller, M. Norman, M. Norris, C. North, J. Novak, G. Nurbek, L. K. Nuttall, K. Obayashi, J. Oberling, C. E. Ochoa, C. O'Connor, J. O'Dell, E. Oelker, M. Oertel, G. Oganesyan, J. J. Oh, T. O'Hanlon, M. Ohashi, F. Ohme, Y. Okabe, I. Oke, R. Oliveira, R. Omer, N. O'Neill, M. Onishi, K. Oohara, P. Ophardt, R. J. Oram, B. O'Reilly, R. O'Shaughnessy, S. Oshino, J. Ostrovska, A. Osumi, I. Ota, G. Othman, M. Otsuka, D. J. Ottaway, A. Ouzriat, H. Overmier, B. J. Owen, A. E. Pace, M. A. Page, A. Pai, S. Pal, M. A. Palaia, M. Pálfi, C. Palomba, H. Pan, J. Pan, K. -C. Pan, P. K. Panda, Shiksha Pandey, Swadha Pandey, P. T. H. Pang, F. Pannarale, B. C. Pant, F. H. Panther, M. Panzeri, F. Paoletti, A. Paoli, A. Paolone, A. Papadopoulos, E. E. Papalexakis, L. Papalini, G. Papigkiotis, A. Paquis, A. Parisi, B. -J. Park, Jihwan Park, Junegyu Park, W. Parker, G. Pascale, D. Pascucci, A. Pasqualetti, L. Passenger, D. Passuello, O. Patane, A. V. Patel, L. Pathak, A. Patra, B. Patricelli, B. G. Patterson, K. Paul, S. Paul, E. Payne, T. Pearce, M. Pedraza, A. Pele, F. E. Peña Arellano, X. Peng, Y. Peng, S. Penn, A. Perreca, J. Perret, D. Pesios, S. Petracca, C. Petrillo, H. P. Pfeiffer, H. Pham, K. A. Pham, K. S. Phukon, H. Phurailatpam, L. Piccari, O. J. Piccinni, M. Pichot, A. Pied, M. Piendibene, F. Piergiovanni, L. Pierini, G. Pierra, V. Pierro, M. Pillas, B. Pillon, L. Pinard, I. M. Pinto, M. Pinto, B. J. Piotrzkowski, M. Pirello, A. Pisarski, M. D. Pitkin, E. Placidi, M. L. Planas, C. Plunkett, R. Poggiani, E. Polini, M. Polo, J. Pomper, L. Pompili, J. Poon, E. Porcelli, A. S. Porter, E. K. Porter, C. Posnansky, J. Powell, G. S. Prabhu, M. Pracchia, A. K. Prajapati, K. Prasai, R. Prasanna, P. Prasia, G. Pratten, G. Principe, G. A. Prodi, P. Prosperi, P. Prosposito, A. Puecher, J. Pullin, M. Punturo, P. Puppo, M. Pürrer, H. Qi, M. Qiao, J. Qin, G. Quéméner, V. Quetschke, P. J. Quinonez, R. Rading, I. Rainho, S. Raja, C. Rajan, B. Rajbhandari, M. R. Raj Sah, K. E. Ramirez, F. A. Ramis Vidal, M. Ramos Arevalo, A. Ramos-Buades, S. Ranjan, M. Ranjbar, K. Ransom, P. Rapagnani, B. Ratto, A. Ravichandran, A. Ray, V. Raymond, M. Razzano, J. Read, J. Redepenning, J. Regan, T. Regimbau, T. Reichardt, S. Reid, C. Reissel, D. H. Reitze, A. I. Renzini, B. Revenu, A. Revilla-Peña, F. Ricci, M. Ricci, A. Ricciardone, J. Rice, J. W. Richardson, M. L. Richardson, K. Riles, H. K. Riley, A. Riminucci, F. Robinet, M. Robinson, A. Rocchi, J. Rodriguez, R. Rodriguez Lopez, L. Rolland, J. G. Rollins, A. E. Romano, R. Romano, A. Romero-Rodríguez, I. M. Romero-Shaw, J. H. Romie, S. Ronchini, T. J. Roocke, T. J. Rosauer, C. A. Rose, D. Rosińska, M. P. Ross, M. Rossello-Sastre, S. Rowan, K. Rowlands, S. K. Roy, S. Roy, T. RoyChowdhury, D. Rozza, P. Ruggi, G. H. Ruiz, E. Ruiz Morales, K. Ruiz-Rocha, V. Russ, S. M. S, S. Sachdev, T. Sadecki, F. Safai Tehrani, P. Saffarieh, S. Safi-Harb, S. Saha, T. Sainrat, S. Sajith Menon, K. Sakai, Y. Sakai, M. Sakellariadou, S. Sakon, F. Salces-Carcoba, L. Salconi, M. Saleem, F. Salemi, M. Sallé, M. Salomé, S. U. Salunkhe, S. Salvador, A. Salvarese, A. Samajdar, P. M. Samir, A. Sanchez, E. J. Sanchez, J. Sanchez, D. Sanchez-Cid, N. Sanchis-Gual, J. R. Sanders, E. M. Sänger, F. Santoliquido, E. Sapkin, F. Sarandrea, T. R. Saravanan, P. Sarkar, A. Sasli, P. Sassi, B. Sassolas, O. Sauter, R. L. Savage, T. Savicheva, T. Sawada, H. L. Sawant, D. Schaetzl, M. Scheel, A. Schiebelbein, M. G. Schiworski, K. Schluterman, P. Schmidt, R. Schnabel, M. Schneewind, R. M. S. Schofield, M. Schoor, K. Schouteden, B. W. Schulte, M. Schulz, B. F. Schutz, E. Schwartz, M. Scialpi, J. Scott, S. M. Scott, R. M. Sedas, T. C. Seetharamu, M. Seglar-Arroyo, Y. Sekiguchi, D. Sellers, N. Sembo, E. G. Seo, J. W. Seo, G. Seong, V. Sequino, M. Serra, C. K. Sethi, A. Sevrin, T. Shaffer, U. S. Shah, M. A. Shaikh, L. Shao, J. Sharkey, A. Sharma, A. K. Sharma, Preeti Sharma, Priyanka Sharma, Sushant Sharma-Chaudhary, P. Shawhan, T. Shen, Z. -H. Shi, K. Shimode, H. Shinkai, S. Shirke, D. H. Shoemaker, D. M. Shoemaker, R. W. Short, S. ShyamSundar, H. Siegel, V. Sierra, D. Sigg, L. Silenzi, P. J. S. Silva, L. Silvestri, M. Simmonds, L. P. Singer, A. Singh, D. Singh, M. K. Singh, N. Singh, S. Singh, M. R. Sinha, P. Sinha, A. M. Sintes, V. Skliris, B. J. J. Slagmolen, T. J. Slaven-Blair, J. Smetana, D. A. Smith, J. R. Smith, J. Smith, L. Smith, W. J. Smith, S. Soares de Albuquerque Filho, M. Soares-Santos, K. Somiya, I. Song, Q. Song, S. Soni, V. Sordini, F. Sorrentino, H. Sotani, N. E. Sovitzky, F. Spada, V. Spagnuolo, A. P. Spencer, M. Spera, P. Spinicelli, A. K. Srivastava, F. Stachurski, V. V. Stanford, A. Stanton, D. A. Steer, N. Steinle, J. Steinlechner, S. Steinlechner, C. Stephens, N. Stergioulas, M. StPierre, J. Stremiz, M. D. Strong, A. Strunk, M. Suchenek, S. Sudhagar, R. Sugimoto, L. Suleiman, K. D. Sullivan, J. Sun, L. Sun, S. Sunil, J. Suresh, P. J. Sutton, K. Suzuki, M. Suzuki, A. Svizzeretto, B. L. Swinkels, A. Syx, M. J. Szczepańczyk, M. Tacca, M. Tagliazucchi, H. Tagoshi, S. C. Tait, H. Takaba, K. Takada, H. Takahashi, R. Takahashi, A. Takamori, S. Takano, H. Takeda, I. Takimoto Schmiegelow, C. Talbot, M. Tamaki, N. Tamanini, D. Tanabe, K. Tanaka, S. J. Tanaka, S. Tanioka, D. B. Tanner, W. Tanner, L. Tao, R. D. Tapia, E. N. Tapia San Martín, A. Taruya, J. D. Tasson, J. G. Tau, A. Tejera, J. G. Temple, Y. Teng, H. Themann, A. Theodoropoulos, M. P. Thirugnanasambandam, L. M. Thomas, M. Thomas, P. Thomas, J. E. Thompson, S. R. Thondapu, E. Thrane, J. Tissino, A. Tiwari, Pawan Tiwari, Praveer Tiwari, S. Tiwari, V. Tiwari, M. R. Todd, E. Tofani, M. Toffano, A. M. Toivonen, K. Toland, T. Tomaru, V. Tommasini, H. Tong, C. I. Torrie, I. Tosta e Melo, E. Tournefier, A. Trapananti, R. Travaglini, F. Travasso, G. Traylor, L. Traylor, M. Trevor, M. C. Tringali, A. Tripathee, G. Troian, A. Trovato, L. Trozzo, R. J. Trudeau, T. Tsang, S. Tsuchida, K. Tsuji, L. Tsukada, A. Tuci, M. Turconi, C. Turski, H. Ubach, A. S. Ubhi, N. Uchikata, T. Uchiyama, R. P. Udall, T. Uehara, V. Undheim, V. Upadhyaya, L. E. Uronen, T. Ushiba, M. Vacatello, H. Vahlbruch, G. Vajente, J. Valencia, M. Valentini, E. Vallejo-Pagès, S. A. Vallejo-Peña, S. Vallero, M. van Dael, E. Van den Bossche, J. F. J. van den Brand, C. Van Den Broeck, M. van der Kolk, M. van der Sluys, A. Van de Walle, J. van Dongen, K. Vandra, M. VanDyke, H. van Haevermaet, J. V. van Heijningen, P. Van Hove, J. Vanier, J. Vanosky, N. van Remortel, M. Vardaro, A. F. Vargas, V. Varma, A. Vecchio, G. Vedovato, J. Veitch, P. J. Veitch, S. Venikoudis, P. Verdier, M. Vereecken, D. Verkindt, B. Verma, S. Verma, Y. Verma, S. M. Vermeulen, F. Vetrano, A. Veutro, A. Viceré, S. Vidyant, A. D. Viets, A. Vijaykumar, A. Vilkha, N. Villanueva Espinosa, E. T. Vincent, J. -Y. Vinet, S. Viret, S. Vitale, A. Vives, L. Vizmeg, B. Vizzone, H. Vocca, D. Voigt, E. R. G. von Reis, J. S. A. von Wrangel, W. E. Vossius, L. Vujeva, S. P. Vyatchanin, J. Wack, L. E. Wade, M. Wade, K. J. Wagner, L. Wallace, R. -Z. Wan, H. Wang, P. Wang, W. H. Wang, Y. F. Wang, Z. Wang, R. L. Ward, J. Warner, M. Was, T. Washimi, N. Y. Washington, D. Watarai, B. Weaver, S. A. Webster, N. L. Weickhardt, M. Weinert, A. J. Weinstein, R. Weiss, L. Wen, K. Wette, C. Wheeler, J. T. Whelan, B. F. Whiting, E. G. Wickens, D. Wilken, B. M. Williams, D. Williams, M. J. Williams, N. S. Williams, J. L. Willis, B. Willke, M. Wils, L. Wimmer, C. W. Winborn, A. Wingfield, J. Winterflood, C. C. Wipf, G. Woan, N. E. Wolfe, H. T. Wong, I. C. F. Wong, T. Wouters, J. L. Wright, M. Wright, B. Wu, C. Wu, D. S. Wu, H. Wu, K. Wu, T. Wu, Z. Wu, E. Wuchner, D. M. Wysocki, V. A. Xu, Y. Xu, N. Yadav, H. Yamamoto, K. Yamamoto, T. S. Yamamoto, T. Yamamoto, R. Yamazaki, T. Yan, H. Yang, K. Z. Yang, Y. Yang, Z. Yarbrough, J. Yébana Carrilero, A. B. Yelikar, X. Yin, J. Yokoyama, T. Yokozawa, M. Yoshihara, S. Yuan, H. Yuzurihara, M. Zanatta, M. Zanolin, M. Zeeshan, T. Zelenova, J. -P. Zendri, M. Zeoli, M. Zerrad, M. Zevin, H. Zhang, J. Zhang, L. Zhang, N. Zhang, R. Zhang, T. Zhang, C. Zhao, J. Zhao, Yue Zhao, Yuhang Zhao, L. -M. Zheng, Y. Zheng, L. Zhizhong, H. Zhong, H. Zhou, H. O. Zhu, X. -J. Zhu, Z. -H. Zhu, Z. Zhu, D. Z. Zieba, A. B. Zimmerman, L. Zimmermann, M. E. Zucker,

Comments:

Subjects: gr-qc

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We report on a gravitational wave search for compact binary coalescences with secondary mass between 0.2 M and 1 M and primary mass between 0.2 M and 10 M, restricting the component mass ratio to lie between 0.1 and 1. The analysis uses data collected by the LIGO and Virgo detectors between 2024 April 10 15:00:00 and 2025 January 28 17:00:00, the second part of the fourth observing run of the LIGO-Virgo-KAGRA Collaboration. Results from two out of three search pipelines show outlier candidates, but not at a sufficient level of significance to provide evidence for detection. We report the combined sensitivity of the current searches over the first and second parts of the observing run to the target sub-solar mass (SSM) BLACK HOLE (BH) population, as well as to neutron star (NS) binaries with one or more sub-solar component. We place upper limits on the merger rate of SSM BHs, ranging from $50 {\rm Gpc}^{-3} {\rm yr}^{-1}$ to~$5000 {\rm Gpc}^{-3} {\rm yr}^{-1}$ (90% confidence) for different component mass combinations. We use the merger rate limits to constrain two illustrative DARK MATTER (DM) scenarios that can form SSM compact objects: primordial BHs, and dark BHs forming in a dissipative DM model. Our search limits the fraction of DM in primordial BHs, assuming a monochromatic mass distribution, to be $\leq$ (0.018-0.032) at 1 M, and $\leq$ (0.10-0.18) at 0.35 M for early-forming binaries; or to be less than 1 at masses above (0.62-0.74) M for late-forming binaries. For the dissipative model, we constrain the fraction of DM for a range of minimum dark BLACK HOLE masses below $1\,M$ to be as low as (1.0-1.1) x $10^{-5}$; we also exclude minimum masses above (0.62-0.74) M, if dark BHs constitute all of the DM. For binary NSs that include sub-solar mass components, assuming a simple, fixed population model we find a merger rate upper limit of $249 {\rm Gpc}^{-3} {\rm yr}^{-1}$.

[abstract 21 / 52] Yes (score: 4)
arXiv:2610.20557 [pdf, ps, other]

Title: Binary-lens amplification of starlight: from magnification flares to quasi-periodic tracking of orbital evolution

Authors: Hanxi Wang, Bence Kocsis, Miguel Zumalacárregui,

Comments: 30 pages, 23 figures, submitted to MNRAS

Subjects: astro-ph.GA astro-ph.CO gr-qc

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Supermassive BLACK HOLE binaries (SMBHB) are expected at the center of galaxies as a result of galaxy mergers. The dynamics and evolution of SMBHBs shed light on the evolution and formation of galaxies, the gravitational wave background and the nature of gravity. Many methods have been proposed to identify sub-parsec SMBHBs via the detection of gravitational waves or the modulation of the emission from the surrounding gaseous environment. In a previous study, we proposed a new method of identifying SMBHBs in non-ACTIVE GALACTIC NUCLEi via gravitational lensing. The caustics, i.e. the source positions with a divergent magnification, exhibit a complex extended geometry which rotates with the binary period. Each caustic-crossing produces an extreme magnification by up to a factor of $10^{6}$. In this work, we generalize the previous study and describe the rich phenomenology of binary-lens amplification of starlight (BLAST). We explore the electroMAGNETic transients produced when accounting for the relative proper motion of the source, either a single or a binary star, the eccentricity and precession of the SMBHB, and the relative inclination. Systems where a star rapidly drifts across the caustic produce a single- or double-peaked flare. In the opposite limit, a star with no relative proper motion produces quasi-periodic lensed starlight (QPLS), i.e., repeated peaks that track the system's orbital evolution. We determine the expected magnification and peak duration in different circumstances, and calculate the magnification curves and their Fourier transforms. This study may help construct search pipelines to identify SMBHBs in electroMAGNETic time-domain surveys.

[abstract 22 / 52] (score: 3)
arXiv:2606.03984 [pdf, ps, other]

Title: Diocotron Modes in Pulsar Magnetospheres: Charge Diffusion and Implications for Radio Emission Variability

Authors: Matthew Goodbred, Anatoly Spitkovsky,

Comments: 18 pages, 8 figures

Subjects: astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

The diocotron instability is a non-axisymmetric plasma instability that should occur generically in the differentially rotating equatorial plane of pulsar MAGNETospheres. We present a series of 3D particle-in-cell (PIC) simulations of the diocotron instability in aligned and oblique pulsars. The instability grows on timescales of the rotation period and develops a strong, stable $m=1$ mode, corresponding to a rotating, dipolar charge asymmetry in the equatorial disk. Stochastic fluctuations in the diocotron mode amplitude and pattern speed drive cross-field diffusion that can rapidly transport charges through the closed zone toward the light cylinder. In the nonlinear stage, the $m=1$ mode produces electric field perturbations which can modulate the polar cap potential drop and the emission beam angle, with possible connections to pulsar variability such as nulling, periodic amplitude modulation, and drifting subpulses.

[abstract 23 / 52] (score: 3)
arXiv:2610.18964 [pdf, ps, other]

Title: EMRIs in Kerr Spacetime: The Role of Inclination Diffusion

Authors: Yael Alush, Nicholas C. Stone, Scott A. Hughes,

Comments: 21 pages, 14 figures, 1 table. Comments are welcome

Subjects: astro-ph.GA astro-ph.HE gr-qc

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

Extreme mass ratio inspirals (EMRIs) are expected to be a major source of gravitational waves (GWs) for the future {\it Laser Interferometer Space Antenna} ({\it LISA}). An EMRI occurs when a compact object, driven by the emission of gravitational radiation, slowly inspirals into a massive BLACK HOLE (MBH). The classical formation channel involves repeated two-body interactions within dense nuclear star clusters. However, both EMRI event rates and the expected distribution of their orbital parameters remain highly uncertain. A major source of this uncertainty is the poorly constrained ratio between gradually inspiraling EMRIs and direct plunges, which do not produce detectable GWs. While most studies of astrophysical EMRI production focus on the Schwarzschild limit, previous work examining the Kerr metric found that the spin of the central MBH can significantly affect the EMRI-to-plunge ratio. This enhancement depends sensitively on orbital inclination, yet earlier studies held inclination fixed. In this work, we develop the mathematical framework describing inclination evolution driven by two-body encounters evolving along Kerr geodesics. By implementing 3D diffusion into Monte Carlo simulations, we show that initially prograde orbits may evolve into retrograde states, thereby converting potential EMRIs into plunges or vice versa. We estimate the EMRI-to-plunge ratio and find that substantial MBH spin enhances the EMRI rate by a factor of $\sim 2.5$. Additionally, even for a non-spinning MBH, modeling the orbits as RELATIVISTIC geodesics rather than Newtonian trajectories increases the number of EMRIs by a similar factor of $\sim 2.5$. The distribution of Kerr EMRI inclinations has a substantial prograde bias that may aid in identifying the subset of loss cone EMRIs within large future EMRI samples.

[abstract 24 / 52] (score: 3)
arXiv:2610.18984 [pdf, ps, other]

Title: Strong-Field Gravitational-Wave Lensing from Ray-Traced Arrival-Time Surfaces

Authors: Luka Vujeva, João S. Santos, Brian C. Seymour,

Comments: 14 pages, 4 figures, 0 hats. Comments are welcome

Subjects: gr-qc astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

The diffraction integral formalism has been greatly successful in describing gravitational wave lensing effects in scenarios where the wavelength of the signal is comparable to the characteristic length scale of the lens, known as the wave optics regime. However, the assumptions required to construct its integrand break down as the source approaches the strong gravity region of a BLACK HOLE lens. In particular, we are interested in the lensed signal from a binary (the source) near a massive BLACK HOLE (the lens). We present a new formalism for obtaining low frequency corrections to sources being lensed in the strong field regime of gravity by leveraging the fact that null geodesics obey the Hamilton--Jacobi equations. In doing so, we are able to construct a time delay surface without relying on the thin lens approximation, and solve the diffraction integral for the resulting surface directly. For a stationary source at $10M$, deep in the strong field regime, when comparing the results with a RELATIVISTIC wave scattering model, we find $6.5\%$ and $0.3\%$ agreement in the peak amplification and first diffractive fringe, respectively. Furthermore, we find a $< 1\%$ agreement with the amplitude of the point mass lens with a source at $10^4 M$ in the weak field, but noticeable dephasing between the peaks of the amplification function at higher frequencies. This work allows for clean interpolation between otherwise separate regimes, valid for sources from $\sim 6M \to \infty$. It provides a transparent, physically motivated framework for computing beyond-geometric optics lensing effects in the strong field regime.

[abstract 25 / 52] (score: 3)
arXiv:2610.19319 [pdf, ps, other]

Title: Hot Molecular Hydrogen in Galaxies at Redshift ~ 0.2-1.5 Revealed by JWST

Authors: Jie Chen, Linhua Jiang, Shuqi Fu, Zijian Zhang, Danyang Jiang, Jing Wang, Ran Wang, Darshan Kakkad,

Comments: 20 pages, 17 figures. Submitted to ApJ

Subjects: astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Molecular hydrogen (H$_2$) is the fundamental component of the molecular gas reservoir that fuels STAR FORMATION and BLACK HOLE growth. While prominent hot H$_2$ emission ($\gtrsim 1000$ K) has been explored in nearby galaxies, its excitation mechanisms at higher redshifts remain poorly constrained. We present a systematic study of hot molecular gas traced via ro-vibrational H$_2$ emitters at z~0.2-1.5 using JWST slitless spectroscopy. Exploiting JWST's great sensitivity to near-infrared H$_2$ ro-vibrational transitions such as H$_2$ 1-0 S(1), we build a sample of 144 H$_2$-luminous galaxies and characterize their multi-wavelength properties. About 96.5% and 80% of these galaxies are detected in the radio and far-infrared (FIR) bands, respectively, and their hot H$_2$ emission strongly correlates with the radio and FIR radiation. Based on radio excess, X-ray emission, and optical diagnostics, 62 sources (43%) exhibit significant AGN activity. The H$_2$ line luminosities of the sample show a sublinear dependence on radio luminosity, while the relation between the H$_2$ luminosities and total infrared luminosities is approximately linear after excluding the radio-excess sources. These scaling relations suggest that STAR FORMATION provides a baseline contribution to hot H$_2$ excitation, while radio-excess sources require an additional contribution from AGN-related processes such as JET- or wind-driven shocks. These results reveal a multi-channel excitation scenario and shed new light on the interplay between STAR FORMATION, AGN activity, and the interstellar medium during galaxy evolution.

[abstract 26 / 52] (score: 3)
arXiv:2610.19718 [pdf, ps, other]

Title: Evidence for Suppressed Non-thermal Broadening in a Flare Ribbon from Stereoscopic Observations

Authors: Ziwen Huang, L. P. Chitta, L. Teriaca,

Comments: 10 pages, 8 figures

Subjects: astro-ph.SR

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Flare ribbons mark the footpoints of newly RECONNECTed MAGNETic loops and are commonly associated with strong plasma flows and enhanced non-thermal broadening of transition-region lines due to impulsive energy deposition. However, the mechanisms governing energy transport into flare ribbons remain uncertain, particularly under different MAGNETic field configurations. We investigate the energy deposition process at a flare ribbon near a sunspot by determining the physical nature of its small-scale downflows. We study small-scale downflows in a remote ribbon during the M7.7-class event on 30 September 2024, using coordinated observations from SDO, IRIS, and Solar Orbiter. We use stereoscopic imaging from Solar Orbiter and IRIS to detect plane-of-sky motions on small scales (200 km). We conduct spectroscopic analysis of IRIS Si IV profiles, complemented by C II and Mg II diagnostics. Apparent downflow speeds measured from Solar Orbiter imaging (limb view) are 85-130 km/s, while IRIS images (disk view) reveal plane-of-sky speeds of 70-85 km/s. In contrast, IRIS Si IV profiles at the brightest ribbon pixels are well approximated by a single Gaussian, with minimal Doppler shifts and unexpectedly small non-thermal widths (10 km/s). Peak Si IV emission also coincides with a deeper Mg II central reversal, while electron densities are one to two orders of magnitude higher than typical quiet-Sun values. The absence of significant line-of-sight velocities and non-thermal broadening differs from typical flare-ribbon behavior. Our results are consistent with a scenario in which plasma motions are guided by highly inclined (nearly horizontal) MAGNETic fields in chromospheric canopy and are not accompanied by strong turbulence or wave motions. This study suggests that flare ribbons can exhibit a wide diversity of lower-atmospheric responses and emphasizes the critical role of MAGNETic field geometry.

[abstract 27 / 52] (score: 3)
arXiv:2610.20260 [pdf, ps, other]

Title: Constrain the Size of Broad Line Region in NGC 1068 Using Sub-millimeter Excess

Authors: Qi Guo, Junzhi Wang, Lingrui Lin, Yuqiang Li, Zhi-yu Zhang, Fengyao Zhu,

Comments:

Subjects: astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Constraining the size of broad-line region (BLR) close to the accretion disk in ACTIVE GALACTIC NUCLEi (AGNs) is key to understand the central engine and evolution of AGN. We propose a new method to constrain the BLR size, based on millimeter to sub-millimeter spectral energy distribution (SED), from which a sub-millimeter excess may be found. Such excess can be used to determine the solid angle of the free-free emission region from BLR, as a region with high electron density and optically thick at sub-millimeter wavelength for free-free continuum. Millimeter to sub-millimeter SED analysis toward the central source S1 in a nearby type II AGN NGC 1068 was done, which gave an upper limit on the solid angle of BLR region as(4.94 +/- 0.61) *10^-6 arcsec^2, corresponding to a radius no more than 0.085 pc. Such a constraint on the BLR size is important for estimating the masses of central supermassive BLACK HOLEs in AGNs.

[abstract 28 / 52] (score: 3)
arXiv:2610.20477 [pdf, ps, other]

Title: LHAASO Constraints on New-Source Cosmic Rays:Abundance Scenarios and Injection Spectral Indices

Authors: Xu-Lin Dong, Pei-Pei Zhang, Qi-Ling Chen, Shu-Wang Cu, Yi-Qing Guo,

Comments: 10 pages, 5 figures

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Recent LHAASO observations indicate that microQUASARs and massive star clusters contribute to Galactic COSMIC RAYs, and likely also to the pre-knee spectral hardening. Their markedly different astrophysical environments, compared with SUPERNOVA remnants (SNRs), may imprint distinct cosmic-ray abundances. We investigate the spectra and composition of new-source COSMIC RAYs under two abundance scenarios: Case-1, the SNR-like composition with enhanced heavy nuclei, and Case-2, the surface abundances of microQUASAR companion stars. We constrain injection spectral indices using LHAASO proton, helium, and all-particle spectra, and use their data for model discrimination. Under the assumption of a unified heavy-element injection spectrum, Case-2 fits the data significantly better than Case-1, but at the cost of large, physically unmotivated differences between heavy-element and He injection indices. This suggests the need to either relax the unified heavy-element injection-index assumption or explore alternative abundance patterns. We predict that if the new-source composition follows Case-1, the individual elemental spectral indices before the knee should remain nearly consistent; if it follows Case-2, the Mg, Si, and Fe spectra will be significantly softer than those of He, C, and O. Future element-resolved energy-spectrum measurements by HERD and LHAASO will provide a decisive test of this discriminating feature.

[abstract 29 / 52] (score: 2)
arXiv:2512.14945 [pdf, ps, other]

Title: A Very Rich Bimodal Galaxy Cluster Merger: RXC J0032.1+1808

Authors: David Wittman, Rodrigo Stancioli, Christopher Hopp, Faik Bouhrik, Reinout van Weeren, Andrea Botteon,

Comments: This version, accepted to ApJ, substantially revises the LOS relative velocity inference and includes a new figure, but with little change to other conclusions. From arXiv v2 to v3 the only change is a metadata correction

Subjects: astro-ph.HE astro-ph.CO

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

The galaxy cluster RXC J0032.1+1808 has been well-studied with optical imaging and gravitational lensing mass maps, both of which reveal an elongated morphology in the north-south direction. We find that its X-ray morphology is bimodal, suggesting that it is in the process of merging; combined with a previously reported detection of a radio relic, we suggest that the system is seen after first pericenter. We extract the global X-ray temperature and unabsorbed luminosity from archival XMM-Newton data, finding $T_X=8.5^{+1.1}_{-0.9}$ keV and $L_X=1.04 \pm 0.03 \times 10^{45}$ erg s$^{-1}$ at 90% confidence in the 0.5-10 keV energy range. We conduct a redshift survey of member galaxies and find that the line-of-sight relative velocity between the two subclusters is 1002-1785 km/s at 68% confidence, although the BCGs have an even larger difference of 2466 km/s. We use publicly available hydrodynamic simulations to show that it cannot be a head-on merger; it is consistent with an impact parameter of 0.5 or 1 Mpc. We also use the simulation set to find initial constraints on the time since pericenter (${\approx}$315-550 Myr) and the locus of possible lines of sight.

[abstract 30 / 52] (score: 2)
arXiv:2604.23189 [pdf, ps, other]

Title: Baryon enhancement in JETs

Authors: Antonio Ortiz, Robert Vertesi,

Comments: Version accepted for publication in PRD. 6 pages, 4 figures

Subjects: hep-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

The enhancement of the baryon production relative to mesons in small-collision systems is considered a breakthrough result of the Large Hadron Collider since a similar effect in heavy-ion collisions is understood by invoking the formation of the strongly-interacting QUARK--gluon plasma. In this paper, a baryon enhancement is reported for $p_{\rm T}^{\rm ch,JET}>15$ GeV/$c$ JETs produced in pp collisions at $\sqrt{s}=13$ TeV simulated with PYTHIA8. The effect can be explained as a transition between QUARK-initiated JETs (low JET multiplicities) to gluon-initiated JETs (high JET multiplicities). The present result contributes to a deeper understanding of the multiplicity dependence of baryon enhancement across different collision systems.

[abstract 31 / 52] (score: 2)
arXiv:2604.25426 [pdf, ps, other]

Title: Augmented reality system for visualising MAGNETic field topology and charged-particle trajectories in MAGNETic fusion plasmas

Authors: Akinobu Matsuyama,

Comments: 16 pages, 7 figures

Subjects: physics.plasm-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

A cost-effective augmented reality (AR) system is presented for visualising three-dimensional MAGNETic field structures and charged-particle trajectories in MAGNETically confined fusion plasmas. The system presented in this study integrates an orbit-following simulation code with a marker-based AR framework using a web camera and the OpenCV library. By synchronizing the time step of the simulation with the frame rate of the camera, the trajectories are continuously updated and superimposed in real time onto the camera image. Through the interactive operation of manipulating the web camera, users can observe three-dimensional structures, such as MAGNETic islands, from various positions and viewing angles. Such an AR environment supports an interactive means of exploring three-dimensional spatial structures that can be difficult to interpret from two-dimensional representations alone. It also provides a common visual representation that can be shared through a display by researchers and students with diverse backgrounds in physics, engineering, and related fields. The developed system has been used in practical exercises at the JT-60SA International Fusion School, with exploratory feedback from students.

[abstract 32 / 52] (score: 2)
arXiv:2606.30274 [pdf, ps, other]

Title: Differential Invariants of Carrollian Spacetimes

Authors: Boris Kruglikov, Eivind Schneider, Wijnand Steneker,

Comments: 24 pages. Minor improvements and typos corrected

Subjects: math.DG gr-qc

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

We compute invariants of Carrollian spacetimes, deriving them from the geometry of the screen bundle. For generic Carrollian structures we specify how to generate the entire algebra of differential invariants, with emphasis on dimension 3, which has special physical relevance. Then, in the framework of JET-spaces, we compute the numerology behind these invariants: the Hilbert and Poincaré functions that govern their numbers according to order. Finally, we compute the Spencer cohomology behind the Carrollian geometry that, in particular, contains the spaces of intrinsic torsion and intrinsic curvature, which are fundamental invariants, important in the equivalence problem and symmetry analysis. Thus, we also discuss symmetry sizes of Carrollian spacetimes.

[abstract 33 / 52] (score: 2)
arXiv:2609.04546 [pdf, ps, other]

Title: Assessing the effect of error field penetration during plasma current ramp-up in the DIII-D tokamak

Authors: C. F. B. Zimmermann, E. M. Bursch, C. Paz-Soldan, J. M. Hanson, N. Leuthold, N. C. Logan, A. O. Nelson,

Comments:

Subjects: physics.plasm-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

This work provides evidence that established error field penetration threshold scalings remain applicable during plasma current ramp-up. In dedicated DIII-D experiments with imposed $n=1$ perturbations during extended $I_p$ ramps, an apparent empirical threshold is found between $2$ and $3$~kA of applied 3D coil current, above which MHD modes are seeded. The imposed perturbation couples to the rational surfaces present during the ramp, seeding near the $q=4$ surface and penetrating as an $m/n=3/1$ mode by the end of the perturbation phase. To interpret these observations, multi-machine penetration threshold scalings are combined with equilibrium-based overlap metrics from the GPEC code, including the in-situ error fields of the device. This modeling reproduces the observed onset in the amplitude scan and classifies mode seeding across a database of 12 ramp-up discharges spanning a range of plasma currents and densities. Across this database, the seeding appears to be controlled primarily by the applied 3D coil current rather than by the plasma current or its ramp rate. Accounting for the in-situ error fields is found to be important for reliable prediction. These results are consistent with the robustness of scaling-based penetration metrics when coupled to detailed 3D field modeling under transient ramp-up conditions, and suggest the importance of accounting for in-situ error fields when assessing additional externally induced perturbations. This work is motivated by future tokamaks in which transient, non-axisymmetric error fields can arise during startup, for example from runaway electron mitigation coils.

[abstract 34 / 52] (score: 2)
arXiv:2610.14505 [pdf, ps, other]

Title: Post-Newtonian secular dynamics of hierarchical triples II. Canonical derivation of the 1PN $\times$ quadrupole cross terms and of the quadrupole-squared term

Authors: Hideyoshi Arakida,

Comments: 24 pages, 9 figures

Subjects: gr-qc

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We derive the secular Hamiltonian of a hierarchical triple from the 1PN ADM three-body Hamiltonian by a two-stage Lie-Hori-Deprit transformation carried out entirely in canonical variables, and use it to settle the RELATIVISTIC cross terms left open in Paper I. A bookkeeping rule enumerates all contributions to each order in the 1PN parameter $δ$ and the hierarchy parameter $\varepsilon$. The 1PN monopole interaction reduces to a renormalization of the inner mass by its binding energy, and the order $δ\varepsilon^{3/2}$, at which Lim and Rodriguez (LR) found a libration term, is empty. The electric and MAGNETic 1PN $\times$ quadrupole cross terms agree exactly with the effective-field-theory result of Kuntz, Serra, and Trincherini; for the MAGNETic term this is the first independent derivation. We give the next-to-leading order 1PN $\times$ quadrupole term in closed form; it depends on the outer argument of pericenter $ω_2$. At quadrupole-squared order we obtain the complete secular Hamiltonian, which generates the secular equations of Will and of Conway and Will; its $2ω_2$ harmonic is a gauge term, removable even on the commensurability between the ZLK period and the nodal precession, by a generator given in closed form via Tremaine's fictitious time. The EIH and ADM descriptions coincide at 1PN order; the formulations differ only in the definition of the elements, for which we give the osculating-contact map. In secular integrations of LR's triples, the eccentricity enhancement with the octupole is controlled by the $ω_2$-dependent part of the next-to-leading order term and is two to three times that of Paper I, while LR's accelerated mergers remain absent.

[abstract 35 / 52] (score: 2)
arXiv:2610.18064 [pdf, ps, other]

Title: Pseudo-spectral methods in gravitational lensing: Spin precession in loop quantum BLACK HOLE spacetimes

Authors: Xiankai Pang, Xiao-Kan Guo,

Comments: abstract updated; 24 pages, 5 figures in main texts, 1 illustration figure in appendix; comments welcome

Subjects: gr-qc

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Gravitational lensing is usually treated as an initial value problem: for a given impact parameter of an unbound orbit, one computes the resulting deflection angle. In this paper we advocate the inverse point of view. For a prescribed deflection angle, the orbit is selected by two boundary conditions at spatial infinity, so that the lensing problem becomes a well-defined two-point boundary value problem, with the impact parameter playing the role of a nonlinear eigenvalue. We show that pseudo-spectral methods based on Chebyshev collocation solve this boundary value problem accurately at modest computational cost, and that the parallel transport equations governing the spin precession of the particle reduce to a single linear system on the same grid. As a concrete application, we compute the spin precession of massive particles in backward scattering off two BLACK HOLE spacetimes from loop quantum gravity: the covariant effective metric and the self-dual loop quantum BLACK HOLE. All equations are written for a general static, spherically symmetric line element with three free functions, so that both spacetimes are handled on the same footing. We find that the quantum corrections are most pronounced for slowly moving particles, while in the ultra-RELATIVISTIC limit the universal spin flip is always recovered. The flip itself is universal, but the rate at which it is approached is not: the derivative of $\cosξ$ with respect to the particle speed at $v=1$ is a strong-field quantity in every backward channel and depends clearly on the quantum parameters of both spacetimes. The framework is not restricted to the models studied here and applies to any static, spherically symmetric spacetime.

[abstract 36 / 52] (score: 2)
arXiv:2610.18952 [pdf, ps, other]

Title: Nonlinear Perturbations of Relativistic Stars

Authors: K. J. Kwon, Abhishek Hegade K. R., Tejaswi Venumadhav, Hang Yu, Nicolás Yunes,

Comments:

Subjects: gr-qc astro-ph.HE astro-ph.SR

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

We extend the general RELATIVISTIC Lagrangian perturbation formalism of Friedman and Schutz [Astrophys. J. 200, 204 (1975)] beyond linear order, retaining full time dependence of the perturbations. We provide general formulae to relate the Lagrangian and Eulerian perturbations to any general perturbative order. As a proof of principle, we apply the framework to tidally perturbed RELATIVISTIC stars in Regge-Wheeler gauge and reduce the second-order field and conservation equations to master equations with a nonlinear source. Projecting the source onto the star's eigenmodes, we obtain a nonlinear equation of motion for the mode amplitudes and the coupling coefficients, which describe the interactions among the eigenmodes and with the external tidal field. Approximating the tidal field and the coupling coefficients, we compute the static quadratic Love number from the quadrupolar fundamental mode alone and find that it reproduces the direct metric-matching value to a reasonable accuracy of $4\%$, up to a further correction arising from the Hamiltonian and momentum constraints of the second-order tidal field.

[abstract 37 / 52] (score: 2)
arXiv:2610.18962 [pdf, ps, other]

Title: Identity Crisis: Untangling Mass-Ordering Artifacts from Compact-Object Pairing in Gravitational-Wave Populations

Authors: Soumendra Kishore Roy, Asad Hussain, L. A. C. van Son, Maya Fishbach, Carl L. Rodriguez, Will M. Farr,

Comments: Codes are publicly availdable on GitHub: https://github.com/SoumendraRoy/Mass_Ordering

Subjects: astro-ph.HE astro-ph.CO gr-qc

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

Mass distributions of binary BLACK HOLE mergers inferred from gravitational-wave observations offer clues to how binaries form. These distributions conventionally label the heavier component as the primary, with mass $m_1$, and the lighter as the secondary, with mass $m_2$, such that $m_1 \geq m_2$. This ordering folds the physically labeled mass distribution along the equal-mass line, potentially reshaping the underlying population structure. In this Letter, we determine which population features can arise from mass ordering and which require genuine astrophysical structure. We show that ordering alone can produce (1) an $m_2$ distribution that declines more rapidly than the $m_1$ distribution, without intrinsic differences between the physically labeled components, and (2) an apparent concentration along equal masses, without correlations that preferentially pair BLACK HOLEs of equal mass. Moreover, different physically labeled populations can produce the same ordered mass distribution. Crucially, however, a preferred companion mass that remains constant as $m_1$ increases requires a characteristic mass scale already present in the physically labeled population. Applied to binary BLACK HOLE mergers in the fifth Gravitational-Wave Transient Catalog, our model recovers such a scale near $m_2 \simeq 50\,\mathrm{M}_\odot$. Around this scale, the merger-rate density declines much more rapidly toward higher $m_2$ than toward lower $m_2$, ruling out an equal or weaker high-$m_2$ decline at 99.45% credibility. This structure therefore requires a characteristic mass scale in at least one physically labeled component, but masses alone cannot determine which component carries it. Any formation model reproducing the observed high-mass binary BLACK HOLE merger population must contain such a scale.

[abstract 38 / 52] (score: 2)
arXiv:2610.18968 [pdf, ps, other]

Title: The Dance of the Little Red Dots: Spectroscopy of Two Blue Companions at z = 3.9 and 5.5 Reveals Young, Metal-Poor Starbursts Merging with Their LRDs within a Few Hundred Myr

Authors: Fabio Pacucci, Pierluigi Rinaldi,

Comments: Submitted for publication in The Astrophysical Journal Letters. 14 pages, 4 figures

Subjects: astro-ph.GA astro-ph.CO astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

The Little Red Dots (LRDs) are compact, red sources, abundant at $4 \lesssim z \lesssim 9$ and likely powered by massive BLACK HOLEs. Photometric studies have found blue companions around them, but none has yet been confirmed spectroscopically. This Letter presents the only two LRD-companion pairs with spectroscopy of both members in the literature: "Waltz" at $z = 3.9$ and "Tango" at $z = 5.5$, with projected separations of $3.6$ and $2.5$ kpc. Both companions lie at the redshift of their LRD, within $132 \, \rm km \, s^{-1}$ and $57 \, \rm km \, s^{-1}$, and are physically identical, but $524$ Myr apart: starbursts $\lesssim 50$ Myr old, metal-poor ($0.2 \, \rm Z_\odot$), dust-free, dynamically cold, and as bright as the LRDs themselves in the rest-frame UV. The LRD in Waltz hosts a $\approx 3 \times 10^{6} \, \rm M_\odot$ BLACK HOLE accreting at half the Eddington rate, a factor of a few above the birth mass of a direct collapse BLACK HOLE, and is embedded in gas as metal-poor as its companion. Orbital modeling shows that Tango is bound in $81\%$ of the allowed orbits and that Waltz is bound if its host halo exceeds $5 \times 10^{10} \, \rm M_\odot$. Both blue companions then merge with their respective LRD within a few hundred Myr. We conclude that we are observing what heavy seeding requires: a young BLACK HOLE beside the metal-poor starburst that the synchronized-pair scenario predicts, in the last steps of a cosmic dance that ends in a merger, and in a galaxy seeded by its BLACK HOLE.

[abstract 39 / 52] (score: 2)
arXiv:2610.18973 [pdf, ps, other]

Title: Spinformation: do gravitational-wave events carry information beyond effective spins?

Authors: Cailin Plunkett, Jack Heinzel, Noah E. Wolfe, Davide Gerosa, Salvatore Vitale,

Comments: 10 pages, 8 figures. Comments welcome!

Subjects: gr-qc astro-ph.HE

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

While the spin vectors of binary BLACK HOLEs offer insight into the astrophysical formation channels of these systems, individual spins are less precisely measured through gravitational-wave observations than the effective inspiral spin $χ_\mathrm{eff}$ and the effective precession spin $χ_\mathrm{p}$. Reducing to effective parameters discards information in the data, but how much information is lost has yet to be demonstrated. Here we show how to quantify whether individual mergers carry information about component spins beyond the constraints implied by effective parameters (a.k.a. spinformation) and apply the technique to GWTC-5. Thresholding on information loss $\gtrsim 0.25$ bits, over $80\%$ of gravitational-wave events in GWTC-5 have component spin posteriors described by $χ_\mathrm{eff}$ alone. Only $\sim3\%$ of gravitational-wave events have substantial spin information not explained by $χ_\mathrm{eff}$ and $χ_\mathrm{p}$. The catalog's component spin information is effectively two-dimensional in $χ_\mathrm{eff}$ and $χ_\mathrm{p}$. Using simulated signals, we find the noise realization can create or destroy over a bit of beyond-$χ_\mathrm{eff}$ information: the structure in real data may therefore be driven by noise. At current sensitivity, component spins provide interpretive\textemdash rather than informational\textemdash advantage over effective parameters.

[abstract 40 / 52] (score: 2)
arXiv:2610.18979 [pdf, ps, other]

Title: A Nonlinear General Implicit Runge-Kutta Integrator for Multifluid Charged Dust and Gas

Authors: Mengxuan Chen, Hui Li, Chong-Chong He, Benjamin D. Wibking, Mark R. Krumholz, Xue-Ning Bai,

Comments: Submitted to ApJS

Subjects: astro-ph.GA

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

Charged dust in MAGNETized gas is subject to aerodynamic drag and the Lorentz force, both of which can be difficult to model numerically in a fluid simulation where their characteristic timescales are shorter than the timestep set by the Courant condition. We present a two-stage general implicit Runge-Kutta (GIRK) source integrator for multifluid charged dust coupled to an ideal MAGNETohydrodynamic (MHD) gas, implemented in the open source GPU-accelerated quokka code. Drag and Lorentz forces are advanced together in one implicit source update, avoiding errors in the terminal drift that can arise when the two forces are advanced in separate substeps. The timestep is compared with a drag-Lorentz timescale to select between resolved and stiff branches. The resolved branch uses Gauss-Legendre coefficients, while the stiff branch uses a coefficient set designed to recover the terminal drift set by the drag-Lorentz balance. We also allow the dust stopping time and charge-to-mass ratio to depend on the evolving state, evaluating them separately at the two implicit stage states and solving the resulting nonlinear stage equations by Picard iteration. The source update conserves total gas-dust momentum, and its computational cost scales linearly with the number of dust species. Tests reproduce the expected drag damping and terminal drift, confirm the predicted gyromotion amplitude and phase errors, demonstrate accurate treatment of state-dependent source coefficients, and recover the expected wave, shock, and instability dynamics in dusty MHD flows.

[abstract 41 / 52] (score: 2)
arXiv:2610.18986 [pdf, ps, other]

Title: Scalar-Assisted Growth of Supermassive Black Holes: Boson-Mass Windows and Observational Constraints

Authors: Jorge Castelo Mourelle, Darío Núñez Zúñiga, Saeed Fakhry, Nicolas Sanchis-Gual,

Comments: 23 pages, 10 figures

Subjects: astro-ph.CO gr-qc

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

We study a phenomenological cosmological model of black-hole growth in which a finite baryonic reservoir and a BOSONic scalar cloud feed the BLACK HOLE simultaneously. The baryonic component accretes through an Eddington-like channel, while the scalar cloud transfers mass through an effective quasibound-state decay rate. Evolving the system directly in redshift within a flat $Λ$CDM background, we scan over $μ$, $M_0$, $M_{c,0}$, and $M_{b,0}$ to assess whether scalar-assisted accretion can accelerate the formation of $10^9M_\odot$ supermassive BLACK HOLEs. We find that the scalar contribution is highly selective in parameter space. For the mass scales explored here, scalar transfer is most efficient for $μ\sim10^{-19}-10^{-16} \mathrm{eV}$, producing rapid cloud depletion and significantly earlier black-hole growth, while outside this interval the evolution remains mainly baryonic. More generally, this efficient window reflects a preferred range of the dimensionless coupling $α=μM_{\rm BH}$ and therefore shifts approximately as $μ\propto M_{\rm BH}^{-1}$. Comparison with observed QUASAR masses and luminosities instead favors lower BOSON masses, broadly around $μ\sim10^{-21}-10^{-20}\mathrm{eV}$. These results are not necessarily in tension, since the BOSON mass that maximizes early growth depends on the characteristic black-hole mass and evolutionary stage. This separation between dynamical efficiency and observational compatibility leaves open complementary roles for different BOSONic mass scales in supermassive BLACK HOLE growth and dark-matter phenomenology.

[abstract 42 / 52] (score: 2)
arXiv:2610.18988 [pdf, ps, other]

Title: Coulomb collision operator

Authors: R. D. Hazeltine,

Comments:

Subjects: physics.plasm-ph

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

Properties of the Coulomb collision operator that have been found useful in plasma kinetic theory and plasma transport theory are gathered and reviewed, with derivations. The use of velocity-space coordinates appropriate to a MAGNETized (drift-kinetic) plasma is emphasized. Little of the material is new, although the derivations may be more detailed than is customary.

[abstract 43 / 52] (score: 2)
arXiv:2610.19096 [pdf, ps, other]

Title: Understanding the Complex Morphology of a Coronal Mass Ejection. III: How to Create a Severe GeoMAGNETic Storm

Authors: Cecilia Mac Cormack, Abril Sahade, Erika Palmerio, Evangelia Samara, Phillip Hess, Robin C. Colaninno, Teresa Nieves-Chinchilla,

Comments:

Subjects: astro-ph.SR

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

On April 21, 2023, a complex filament eruption produced an Earth-directed coronal mass ejection (CME) that triggered the first severe geoMAGNETic storm of solar cycle 25. The primary objective of this work is to understand the physical origin of the severe impact of this CME on Earth. We explore the CME's complex morphology by simulating the eruption using the thermodynamic MAGNETohydrodynamic (MHD) model CORHEL-CME. We model the pre-eruptive structure as two intertwined MAGNETic flux ropes and validate the early evolution of the event by comparing synthetic observables generated from the model with extreme-ultraviolet and white-light observations. We then compare the simulated CME structure with in situ measurements. From our analysis, we conclude that the CME merged with a stream interaction region (SIR) before reaching Earth. This interaction compressed the CME sheath, producing a sustained negative $B_n$ component that, together with the associated enhancement in solar wind density and velocity, triggered the geoMAGNETic storm. The internal configuration of the MAGNETic flux rope, which also maintained a sustained southward component during its propagation toward Earth, intensified the storm to severe levels. This model-data comparison underscores the power of using MHD simulations, when validated by multi-viewpoint observations, to reveal hidden dynamical processes and improve the understanding and prediction of space weather impacts.

[abstract 44 / 52] (score: 2)
arXiv:2610.19146 [pdf, ps, other]

Title: SQuIGGLE: Radio AGN Found Predominantly in Young, Gas-rich Post-starburst Galaxies at z ~ 0.7

Authors: Vincenzo R. D'Onofrio, Justin S. Spilker, Krista L. Smith, Rachel Bezanson, Robert Feldmann, Alex J. Geiger, Andy D. Goulding, Jenny E. Greene, Mariska Kriek, Anika Kumar, Yuanze Luo, Desika Narayanan, David J. Setton, Katherine A. Suess, Margaret E. Verrico, Pengpei Zhu,

Comments: 21 pages, 11 figures, submitted to ApJ. Comments welcome!

Subjects: astro-ph.GA

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

The processes that rapidly quench massive galaxies and maintain their quiescence remain poorly understood. Substantial molecular gas reservoirs can survive this shutdown in post-starburst galaxies, raising the question of what prevents the remaining gas from efficiently forming stars. We present deep, subarcsecond VLA 6 GHz observations of 52 massive SQuIGGLE post-starburst galaxies at $z\sim0.7$ to test the prevalence and mechanical impact of radio activity during the gas-rich post-burst phase. We detect 6 GHz continuum emission in 18/52 galaxies ($\approx$35\%), spanning $\log(L_{1.4\,{\rm GHz}}/{\rm W\,Hz^{-1}})\simeq23.0$--$25.0$ and generally exceeding the contributions expected from ongoing STAR FORMATION and the fading starburst, favoring an AGN origin. Ancillary data at other wavelengths provide little evidence for a population of luminous, radiatively efficient AGN, suggesting that these sources are instead dominated by comparatively weak, mechanically powered radio AGN. Radio activity is strongly concentrated within the first $\sim$200 Myr post-burst and is predominantly associated with galaxies retaining substantial gas reservoirs. Above a common radio luminosity threshold, the radio detection fraction is enhanced by a factor of $\approx$2.5 relative to the radio AGN candidate fraction in mass- and redshift-matched quiescent LEGA-C galaxies, primarily due to lower power sources. For efficient JET--ISM coupling, the inferred mechanical power could supply the approximate energy required to unbind the molecular gas on timescales comparable to its observed decline. Together, these results identify a population of radiatively inefficient AGN hosted predominantly by young, gas-rich post-starburst galaxies at $z\sim0.7$ and suggest that they may have a role in maintaining inefficient STAR FORMATION.

[abstract 45 / 52] (score: 2)
arXiv:2610.19204 [pdf, ps, other]

Title: Studying the Near-horizon Jet of M87 using Millimeter Balloon-borne VLBI stations

Authors: Felix M. Thiel, Dominic W. Pesce, Mayukh Bagchi, Laura M. Fissel, Lindy Blackburn,

Comments: 14 pages, 7 figures, Submitted for publication to ApJ

Subjects: astro-ph.IM

Created: 2026-10-13; Updated: 2026-10-15; Datestamp: 2026-10-15

In this paper we present synthetic Very Long Baseline Interferometry (VLBI) observations of M87 between a near-future configuration of the Event Horizon Telescope (EHT) and one or multiple 2.5 m-class balloon-borne VLBI stations on a northern transatlantic flight trajectory launching from Kiruna, Sweden. These balloon-borne VLBI stations have the advantage of operating above 99.5% of the atmosphere and their motion allows for efficient sampling of the uv-plane. Assuming frequency phase transfer between 230 and 86 GHz we run these simulations using a modified version of the ngehtsim software package. Our simulations demonstrate the ability of such a VLBI array to probe M87 at the JET base adding baselines down to 0.2 G$λ$ for a single balloon-VLBI station and 0.07 G$λ$ for three balloon VLBI stations. Using the Bayesian imaging software Comrade.jl, we demonstrate the recovery of JET structures up to 150 $μ$as in size for a single balloon and up to 300 $μ$as in size with three balloons. Finally, we test the improvement in JET image fidelity by computing the normalized cross-correlation (NXCOR) and normalized-root-mean-square error (NRMSE) between the image reconstruction and ground truth. We find a factor of 1.2 improvement in the JET NRMSE for a single balloon and a factor of 1.3 improvement for 3 balloons as compared to EHT-only simulations.

[abstract 46 / 52] (score: 2)
arXiv:2610.19595 [pdf, ps, other]

Title: A possible evolutionary connection between high-mass X-ray binary pulsars and isolated rotation-powered pulsars

Authors: Jun Yang,

Comments: Accepted for publication in the Journal of High Energy Astrophysics

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We investigate the long-term spin evolution of high-mass X-ray binary (HMXB) pulsars in the Small Magellanic Cloud (SMC) using archival measurements of spin periods and period derivatives from XMM-Newton, Chandra, and RXTE. In the P-|dP/dt| plane, the HMXB pulsars follow an approximately linear relation in log-log space with a slope of 1.02 +/- 0.11, similar to the trend shown by the youngest isolated rotation-powered pulsars (RPPs; e.g., Manchester et al., 2005; Lorimer and Kramer, 2005). For comparison, young RPPs from the ATNF Pulsar Catalogue give slopes that depend strongly on the characteristic-age cut: 1.10 +/- 0.16 for characteristic ages below 10,000 years and 0.72 +/- 0.08 for characteristic ages below 100,000 years. The full non-recycled population shows no significant correlation. The HMXB pulsars lie in the same characteristic-age range (approximately 1,000-10,000 years) as the youngest RPPs, but at spin periods two to three orders of magnitude longer. Reference characteristic-age contours in the HMXB P-|dP/dt| plane are roughly parallel to this relation, consistent with a continuous evolutionary sequence.

[abstract 47 / 52] (score: 2)
arXiv:2610.19838 [pdf, ps, other]

Title: A heterogeneous set of unusual QUASARs selected from astrometry and broad-band photometry

Authors: C. Cheng, K. Valeckas, L. Christensen, A. Henderson de la Fuente, L. Fuglsang, V. Vuolteennaho, Pyykkinen, R. H. Rasmussen, S. Bijavara Seshashayana, J. P. U. Fynbo,

Comments: 15 pages, 31 figures. Submitted to OJA. Comments very welcome. This manuscript has the character of a research note

Subjects: astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

The aim of this study is to explore methods for how to identify new QUASARs with different properties with regard to reddening, redshift, the presence of broad absorption lines from outflows, or other rare properties affecting the broad-band colours. We use Gaia-based astrometric pre-selection to study only sources that have zero parallax and zero proper motion within errors. We subsequently match these sources with information from wide-area photometric surveys and build colour-colour diagrams. Based on these diagrams we select targets for follow-up spectroscopy. In the subsequent analysis we also apply observations from SPHEREx to firmly establish redshifts. We secure spectroscopic observations for 24 sources. Of these, three are found to be stars and the remaining 21 are classified as QUASARs spanning a redshift range from z=0.139 to z=3.732. The majority of the sources located away from the normal QUASAR locus in colour-colour diagrams are found to be broad-absorption-line QUASARs. A single source, the lowest redshift source at z=0.139, is reminiscent of the so-called Little Red Dots found at high redshifts with JWST. Using the simple procedure followed here it is possible to locate previously undiscovered QUASARs with interesting properties, in particular Broad Absorption Line QUASARs and QUASARs with unusual extinction.

[abstract 48 / 52] (score: 2)
arXiv:2610.20017 [pdf, ps, other]

Title: Testing Charged Black Holes Embedded in Anisotropic Matter and Surrounded by Plasma through Gravitational Lensing: Bounds from the Sloan Lens ACS Survey

Authors: Ritesh Pandey, Shubham Kala, Amare Abebe, Hemwati Nandan, G. G. L. Nashed,

Comments: 15 pages, 9 figures, comments are welcome

Subjects: gr-qc astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We investigate weak gravitational lensing by a charged BLACK HOLE surrounded by anisotropic matter, described by the two-component Kiselev metric, and immersed in a homogeneous plasma. We first examine the BLACK HOLE geometry and horizon structure and then derive the weak-deflection angle from the Hamiltonian description of light propagation in plasma, using an expansion with a fixed turning point that we verify against direct numerical integration. Using the gravitational lens equation, we obtain the Einstein-ring angle, the image positions, the total magnification and the fractional magnifications of the primary and secondary images. We then confront the model with the Einstein radii of two galaxy-scale lenses of the Sloan Lens ACS Survey, J0008$-$0004 and J0029$-$0055. Because the Einstein angle cannot be smaller than the reduced deficit deflection, the observed radii give the mass-independent bounds $K<6.5\times10^{-6}$ and $K<4.2\times10^{-6}$, respectively. The charge correction to the Einstein radius is suppressed by $r_s/R_E\approx 5\times10^{-6}$ and is unobservable, while the plasma parameter at the optical wavelengths of the SLACS imaging is of order $10^{-22}$ and cannot be constrained. Our results show that galaxy-scale strong lensing data place stringent limits on anisotropic matter surrounding the lens, whereas plasma effects can be probed only at low radio frequencies.

[abstract 49 / 52] (score: 2)
arXiv:2610.20026 [pdf, ps, other]

Title: Tracking a solar energetic eruption and associated energetic particles from Sun to spacecraft

Authors: D. E. Morosan, M. Baumgartner-Steinleitner, K. Bhandari, N. Dresing, G. Farwa, J. A. J. Mitchell, C. Palmroos, A. Razquin, J. Zhang, C. Briand, K. Dissauer, A. Fedeli, J. Gieseler, E. K. J. Kilpua, S. Normo, J. Pomoell, D. J. Price, A. M. Veronig, A. Warmuth, R. Vainio,

Comments: 15 pages, 11 figures

Subjects: astro-ph.SR physics.space-ph

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Context. Solar energetic particles (SEPs) in the heliosphere are produced by flaring processes on the Sun or shocks driven by coronal mass ejections (CMEs). Electrons, in particular, are regularly detected remotely as electroMAGNETic radiation (X-rays or radio emission), which they generate through various processes, as well as in situ by spacecraft monitoring the Sun and the heliosphere. Aims. We aim to combine remote-sensing and in situ observations of an energetic solar eruption to link energetic processes in the solar corona to energetic particles observed in situ in the heliosphere. This will be done using the tools developed in the Horizon Europe SOLER project. Methods. Here, we investigate a solar energetic eruption at the Sun together with its associated signatures of accelerated electrons observed at radio and X-ray wavelengths and combine these remote observations to in situ particles observed by spacecraft on 10 March 2024. These observations are combined with a MAGNETo-hydrodynamic (MHD) model of the solar corona in order to make the remote to in situ connections. Results. We observe a high-energy SEP event at multiple spacecraft (>25 MeV protons and 1 MeV electrons), despite the event being associated with a slow white-light CME. Remote observations of the Sun show that the event was associated with a fast large scale coronal wave (1400 km/s) and also multiple regions where electrons are accelerated around this large scale wave observed as type II radio bursts. In addition, we observe a strong coronal dimming away from the main flaring region, providing evidence of field lines getting opened to interplanetary space, dislocated from the flare site.

[abstract 50 / 52] (score: 2)
arXiv:2610.20201 [pdf, ps, other]

Title: Biases in Ringdown Tests of General Relativity from Gravitational-Wave Microlensing

Authors: Sreelakshmi Mundakkal Dasan, Anuj Mishra, Apratim Ganguly,

Comments: 11 pages, 7 figures

Subjects: gr-qc astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

Gravitational-wave (GW) ringdown signals provide a powerful probe of the strong-field regime of general relativity (GR) through BLACK HOLE spectroscopy and tests of the Kerr hypothesis. However, unmodeled propagation effects can bias the inference of remnant properties and the interpretation of ringdown features. We investigate the impact of gravitational lensing on ringdown inference and tests of GR using GW150914-like simulated signals spanning the long-wavelength, wave-optics, and geometric-optics regimes. We perform complementary time-domain post-merger and frequency-domain full inspiral--merger--ringdown analyses using unlensed waveform models. We find that lensing in the wave-optics regime can produce substantial biases in the inferred remnant mass and spin and can strongly affect the inferred modal content of the ringdown. In particular, it can spuriously favor the presence of the first overtone, with $\log_{10}\mathcal{B}^{221}_{220}\sim40$, even though the injected signal has no support for it. Parameterized ringdown tests can likewise yield strong apparent support for deviations from the Kerr quasinormal mode (QNM) spectrum, with $\log_{10}\mathcal{B}^{\rm modGR}_{\rm GR}\sim8$. In contrast, the evidence for higher-order modes remains largely unchanged for the simulated signals considered here. The parameterized analysis using the entire signal further shows that microlensing can bias the inferred frequency of the dominant $(2,2,0)$ QNM. These results demonstrate that unmodeled microlensing can produce systematic biases and spurious signatures in ringdown analyses, potentially affecting precision tests of the Kerr hypothesis.

[abstract 51 / 52] (score: 2)
arXiv:2610.20332 [pdf, ps, other]

Title: IRAC-Excess Galaxies in the NIRSpec Wide Survey: physical properties of bright EELGs at $z\sim7$ and implications for Reionization

Authors: Katherine Ormerod, Renske Smit, Joris Witstok, Anna de Graaff, Michael V. Maseda, Andrew J. Bunker, Chris Willott,

Comments: 26 pages, submitted to MNRAS

Subjects: astro-ph.GA

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

We present an analysis of 23 Spitzer/IRAC excess galaxies at $5.66 < z < 7.64$, observed as part of the NIRSpec Wide GTO survey. With NIRSpec PRISM spectroscopy, we measure a median rest-frame [OIII]$+\rm{H}β$ EW $=1583$~Å, consistent with predictions from the pre-JWST selection and we identify $17/23$ $(\sim74\%)$ of our sample as extreme emission line galaxies (EELGs), based on a selection of [OIII]$+\rm{H}β$ EW $\geq1000$~Å. The typical EELG is powered by star-formation rather than ACTIVE GALACTIC NUCLEi (AGN) based on their line widths, line ratios and absence of high-ionization lines, though we cannot exclude an AGN contribution in a few individual sources. We find that our luminous ($\langle M_\mathrm{UV}\rangle=-20.7$) EELG sample is characterised by sub-solar metallicities $(7.38 < \rm 12 + \log(O/H) < 8.12)$, young stellar populations ($t_\star \sim 20$ Myr), and enhanced ionizing photon production efficiencies, with median $\log_{10}(ξ_\mathrm{ion}/\mathrm{erg}^{-1}~\mathrm{Hz}) = 25.62$. We find that more UV luminous ($\sim L_\mathrm{UV, z=7}^\ast$) EELGs exhibit systematically lower O32 ratios than fainter ($\sim 0.1\times L_\mathrm{UV}^\ast$) EELGs at fixed [OIII]$+\rm{H}β$ EW, indicating less extreme radiation fields and/or lower gas densities than their fainter counterparts. Furthermore, bright EELGs exhibit low neutral hydrogen column densities, consistent with a scenario in which they have largely ionized their circumgalactic medium (CGM). Despite this, we find very low Lyman-$α$ escape fractions ($<2$\%), suggesting these systems reside in relatively small ($\lesssim 0.25$~pMpc) ionized regions of the intergalactic medium (IGM), possibly suggesting that bright galaxies have a minor contribution to reionization.

[abstract 52 / 52] (score: 2)
arXiv:2610.20423 [pdf, ps, other]

Title: Rotochemical heating of neutron stars in 2D

Authors: Mikhail V. Beznogov, Jerome Novak, Dany Page, Adriana R. Raduta,

Comments: 12 pages, 6 figures, submitted to ApJ

Subjects: astro-ph.HE

Created: 2026-10-14; Updated: 2026-10-15; Datestamp: 2026-10-15

The matter inside a spinning-down neutron star (NS) undergoes a slow compression that may drive it out of chemical equilibrium and, consequently, trigger non-equilibrium nuclear reactions that can heat up the star. This phenomenon is called rotochemical heating, and it is relatively well-investigated in the literature. Historically, it has been studied almost exclusively via 1D spherically symmetric models. However, rapidly rotating NSs are not spherically symmetric. We present pioneering simulations of rotochemical heating in full General Relativity in 2D axially symmetric models without relying on the slow rotation approximation. We explicitly follow thermal, mechanical, and chemical evolution of rotating NSs as they spin down taking into account both radial and angular distributions of temperature, composition, and mechanical structure. The simplest model is employed: only nucleonic composition, only the non-equilibrium modified Urca process as the main heating/cooling mechanism, and no superfluidity. We analyze the impact of the MAGNETic field strength as well as the effects of the heat blanketing envelope, initial rotation frequency, NS mass, and core EOS. Most of our conclusions coincide with the results of previous works on this topic, with one important exception. We have found a strong dependence of the cooling curves during the rotochemical heating phases on the core EOS, whereas in the literature it was regarded as very weak. The most likely explanation for this discrepancy is that the authors of the previous works have not considered EOSs with wide enough range of variation of the symmetry energy as a function of density.