Current date: 2026-09-18

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Datestamp limit: 2026-09-18 (0 days ago)

Created/updated limit: 2026-09-11 (7 days ago)

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OAI-PMH request: http://export.arxiv.org/oai2?verb=ListRecords&from=2026-09-18&until=2026-09-18&set=physics&metadataPrefix=arXiv

Scoring abstracts

Number of records retrieved: 893

Keyword score statistics

score 9 -- 1 abstracts

score 7 -- 2 abstracts

score 5 -- 4 abstracts

score 4 -- 5 abstracts

score 3 -- 6 abstracts

score 2 -- 19 abstracts

in total -- 37 abstracts

Articles that appeared on 2026-09-18

[abstract 1 / 37] Wow! (score: 9)
arXiv:2609.19477 [pdf, ps, other]

Title: Lepto-hadronic modeling of BLAZARs associated with well-reconstructed high-energy neutrino events

Authors: Leonard Pfeiffer, Margot Boughelilba, Simone Garrappa, Sara Buson, Massimiliano Lincetto, Annette Bremer,

Comments:

Subjects: astro-ph.HE

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

The association of ACTIVE GALACTIC NUCLEi (AGN) with high-energy neutrinos has been studied through population and individual source analyzes, but whether these associations reflect physical processes or chance coincidences remains open. Blazars, AGN with RELATIVISTIC JETs aligned with the line of sight, spatially consistent with IceCube high-energy events, offer a natural framework to address this question. Combining multifrequency observations with physically motivated emission models allows us to assess whether these sources can plausibly account for the detected neutrinos. We study six BLAZARs with single gamma-ray counterparts to well-reconstructed IceCAT-1 high-energy events, accounting for the improved localization expected from IceCAT-2, and compile their multifrequency spectral energy distributions (SEDs). We model these sources within a lepto-hadronic framework, exploring their parameter space to reproduce the observed emission while favoring solutions that maximize neutrino production. The SEDs can be reproduced with compact emission regions close to the broad-line region with moderate Doppler factors. The emission is generally leptonic-dominated, with subdominant contributions from hadronic cascades, except for one source where the gamma-rays are hadronic-dominated. For four, the energy density of the RELATIVISTIC particles is close to equipartition with the MAGNETic field. The predicted neutrino detection rates reach up to $~5x10^{-2}$ per year, mostly compatible with one observed IceCube event under Poisson statistics. While these BLAZARs are unlikely to significantly contribute to the diffuse neutrino flux, their properties are consistent with being possible counterparts to individual neutrino events, driven by contributions of external photon fields to the hadronic interaction rate, even for sources where these fields have previously been considered as non-significant.

[abstract 2 / 37] Wow! (score: 7)
arXiv:2603.25669 [pdf, ps, other]

Title: Double-Adiabatic Equations of State for Relativistic Plasmas

Authors: Agnieszka Wierzchucka, Pablo J. Bilbao, Alexander G. R. Thomas, Dmitri A. Uzdensky, Alexander A. Schekochihin,

Comments: 22 pages, 4 figures, accepted to JPP

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

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

The adiabatic equation of state $P \propto n^Γ$ describes the pressure evolution of highly collisional, isotropic plasmas in terms of their density, providing a possible closure of the fluid moment hierarchy in the absence of heat fluxes and dissipation. An analogous closure exists for collisionless, MAGNETised plasmas, whose pressure tensor is anisotropic with respect to the MAGNETic field, and the closure is therefore double adiabatic, prescribing the evolution of the parallel and perpendicular pressures in terms of the MAGNETic-field strength and density. Here, we present a general first-principle formalism to derive adiabatic laws using the symmetries of the system. With this theory we recover the adiabatic equation of state $P \propto n^Γ$ for isotropic plasmas and the double-adiabatic equations of state for collisionless, MAGNETised plasmas. We extend the latter to the RELATIVISTIC regime, finding that their exact functional form depends on the pressure anisotropy and is not a simple power law. Our double-adiabatic equations of state describe simple geometries, like MAGNETic mirrors or compressed homogeneous plasmas, as well as complex high-energy astrophysical processes, such as the evolution of plasmoid structures formed during MAGNETic RECONNECTion.

[abstract 3 / 37] Wow! (score: 7)
arXiv:2609.19910 [pdf, ps, other]

Title: The rise and decline of a transient obscuration event in a moderately distant type-I QUASAR

Authors: A. Akylas, A. Georgakakis, E. Pouliasis, I. Georgantopoulos, C. Ricci, M. Chira, A. Ruiz, E. M. Xilouris,

Comments:

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

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Outflows of ionised material, often dubbed warm absorbers (WAs), are common in nearby Seyferts but sparse in distant and more energetic QUASARs (QSOs). We present multi-epoch X-ray and optical observations of the serendipitously identified type-I QSO 2MASS J14302580+4159572 at a redshift of $z=0.35$, revealing the rare rise and decline of a transient ionised absorber over a 22-year timescale. The discovery observations were obtained with XMM-Newton between 2002 and 2005. The first two observations show unremarkable X-ray spectra typical of unobscured type-I QSOs, whereas the 2005 observation reveals a pronounced suppression of the spectrum below $\sim3\,\mathrm{keV}$. Spectral analysis shows that this event is produced by a moderately ionised absorber with column density $N_{\rm H}\simeq5\times10^{22}\,\mathrm{cm^{-2}}$ and ionisation parameter $\logξ\simeq1.4$. Joint analysis of XMM-Newton, NUSTAR, and SWIFT/XRT observations spanning 22 years indicates that the absorber remained stable for nearly 18 years before weakening in the 2023--2024 SWIFT/XRT data. Throughout this period, the intrinsic 3--10 keV continuum remained remarkably stable, indicating that the observed variability is driven by changes in line-of-sight ionised absorption rather than intrinsic luminosity fluctuations. We interpret the event as a thermally driven ionised outflow located outside the broad-line region (BLR), at sub-parsec to parsec scales, with a density of order $10^{6}\,\mathrm{cm^{-3}}$. Supporting this scenario, the high-ionisation [O\,III] $\lambda4363$ emission line varies in tandem with the X-ray absorption, suggesting that the outflow progressively modifies the ionisation state of the inner narrow-line region (NLR) on decadal timescales. These observations provide a rare view of the long-term evolution of a QUASAR warm absorber and its impact on the circumnuclear environment.

[abstract 4 / 37] Yes (score: 5)
arXiv:2508.18079 [pdf, ps, other]

Title: Open Data from LIGO, Virgo, and KAGRA through the First Part of the Fourth Observing Run

Authors: The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, A. G. Abac, I. Abouelfettouh, F. Acernese, K. Ackley, C. Adamcewicz, S. Adhicary, D. Adhikari, N. 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, S. Albanesi, W. Ali, S. Al-Kershi, C. Alléné, A. Allocca, S. Al-Shammari, P. A. Altin, S. Alvarez-Lopez, W. Amar, O. Amarasinghe, A. Amato, F. Amicucci, C. Amra, A. Ananyeva, S. B. Anderson, W. G. Anderson, M. Andia, M. Ando, M. Andrés-Carcasona, T. Andrić, J. Anglin, S. Ansoldi, J. M. Antelis, S. Antier, M. Aoumi, E. Z. Appavuravther, S. Appert, S. K. Apple, K. Arai, A. Araya, M. C. Araya, M. Arca Sedda, 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, F. Attadio, F. Aubin, K. AultONeal, G. Avallone, E. A. Avila, S. Babak, C. Badger, S. Bae, S. Bagnasco, L. Baiotti, R. Bajpai, T. Baka, A. M. Baker, K. A. Baker, T. Baker, G. Baldi, N. Baldicchi, M. Ball, G. Ballardin, S. W. Ballmer, S. Banagiri, B. Banerjee, D. Bankar, T. M. Baptiste, P. Baral, M. Baratti, J. C. Barayoga, B. C. Barish, D. Barker, N. Barman, P. Barneo, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, A. M. Bartoletti, M. A. Barton, I. Bartos, A. Basalaev, R. Bassiri, A. Basti, M. Bawaj, P. Baxi, J. C. Bayley, A. C. Baylor, P. A. Baynard, M. Bazzan, V. M. Bedakihale, F. Beirnaert, M. Bejger, D. Belardinelli, A. S. Bell, D. S. Bellie, L. Bellizzi, W. Benoit, I. Bentara, J. D. Bentley, M. Ben Yaala, S. Bera, F. Bergamin, B. K. Berger, S. Bernuzzi, M. Beroiz, C. P. L. Berry, D. Bersanetti, T. Bertheas, A. Bertolini, J. Betzwieser, D. Beveridge, G. Bevilacqua, N. Bevins, R. Bhandare, R. Bhatt, D. Bhattacharjee, S. Bhattacharyya, S. Bhaumik, V. Biancalana, A. Bianchi, I. A. Bilenko, G. Billingsley, A. Binetti, S. Bini, C. Binu, S. Biot, O. Birnholtz, S. Biscoveanu, A. Bisht, M. Bitossi, M. -A. Bizouard, S. Blaber, J. K. Blackburn, L. A. Blagg, C. D. Blair, D. G. Blair, N. Bode, N. Boettner, G. Boileau, M. Boldrini, G. N. Bolingbroke, A. Bolliand, L. D. Bonavena, R. Bondarescu, F. Bondu, E. Bonilla, M. S. Bonilla, A. Bonino, R. Bonnand, A. Borchers, S. Borhanian, V. Boschi, S. Bose, V. Bossilkov, Y. Bothra, A. Boudon, L. Bourg, M. Boyle, A. Bozzi, C. Bradaschia, P. R. Brady, A. Branch, M. Branchesi, I. Braun, T. Briant, A. Brillet, M. Brinkmann, P. Brockill, E. Brockmueller, A. F. Brooks, B. C. Brown, D. D. Brown, M. L. Brozzetti, S. Brunett, G. Bruno, R. Bruntz, J. Bryant, Y. Bu, F. Bucci, J. Buchanan, O. Bulashenko, T. Bulik, H. J. Bulten, A. Buonanno, K. Burtnyk, R. Buscicchio, D. Buskulic, C. Buy, R. L. Byer, G. S. Cabourn Davies, R. Cabrita, V. Cáceres-Barbosa, L. Cadonati, G. Cagnoli, C. Cahillane, A. Calafat, T. A. Callister, E. Calloni, S. R. Callos, M. Canepa, G. Caneva Santoro, K. C. Cannon, H. Cao, L. A. Capistran, E. Capocasa, E. Capote, G. Capurri, G. Carapella, F. Carbognani, M. Carlassara, J. B. Carlin, T. K. Carlson, M. F. Carney, M. Carpinelli, G. Carrillo, J. J. Carter, G. Carullo, A. Casallas-Lagos, J. Casanueva Diaz, C. Casentini, S. Y. Castro-Lucas, S. Caudill, M. Cavaglià, R. Cavalieri, A. Ceja, G. Cella, P. Cerdá-Durán, E. Cesarini, N. Chabbra, W. Chaibi, A. Chakraborty, P. Chakraborty, S. Chakraborty, S. Chalathadka Subrahmanya, J. C. L. Chan, M. Chan, K. Chang, S. Chao, P. Charlton, E. Chassande-Mottin, C. Chatterjee, Debarati Chatterjee, Deep Chatterjee, M. Chaturvedi, S. Chaty, K. Chatziioannou, A. Chen, A. H. -Y. Chen, D. Chen, H. Chen, H. Y. Chen, S. Chen, Yanbei Chen, Yitian Chen, H. P. Cheng, P. Chessa, H. T. Cheung, S. Y. Cheung, F. Chiadini, G. Chiarini, A. Chiba, A. Chincarini, M. L. Chiofalo, A. Chiummo, C. Chou, S. Choudhary, N. Christensen, S. S. Y. Chua, G. Ciani, P. Ciecielag, M. Cieślar, M. Cifaldi, B. Cirok, F. Clara, J. A. Clark, T. A. Clarke, P. Clearwater, S. Clesse, F. Cleva, E. Coccia, E. Codazzo, P. -F. Cohadon, S. Colace, E. Colangeli, M. Colleoni, C. G. Collette, J. Collins, S. Colloms, A. Colombo, C. M. Compton, G. Connolly, L. Conti, T. R. Corbitt, I. Cordero-Carrión, S. Corezzi, N. J. Cornish, I. Coronado, A. Corsi, R. Cottingham, M. W. Coughlin, A. Couineaux, P. Couvares, D. M. Coward, R. Coyne, A. Cozzumbo, J. D. E. Creighton, T. D. Creighton, P. Cremonese, S. Crook, R. Crouch, J. Csizmazia, J. R. Cudell, T. J. Cullen, A. Cumming, E. Cuoco, M. Cusinato, L. V. Da Conceição, T. Dal Canton, S. Dal Pra, G. Dálya, B. D'Angelo, S. Danilishin, S. D'Antonio, K. Danzmann, K. E. Darroch, L. P. Dartez, R. Das, A. Dasgupta, V. Dattilo, A. Daumas, N. Davari, I. Dave, A. Davenport, M. Davier, T. F. Davies, D. Davis, L. Davis, M. C. Davis, P. Davis, E. J. Daw, M. Dax, J. De Bolle, M. Deenadayalan, J. Degallaix, M. De Laurentis, F. De Lillo, S. Della Torre, W. Del Pozzo, A. Demagny, F. De Marco, G. Demasi, F. De Matteis, N. Demos, T. Dent, A. Depasse, N. DePergola, R. De Pietri, R. De Rosa, C. De Rossi, M. Desai, R. DeSalvo, A. DeSimone, R. De Simone, A. Dhani, R. Diab, M. C. Díaz, M. Di Cesare, G. Dideron, T. Dietrich, L. Di Fiore, C. Di Fronzo, M. Di Giovanni, T. Di Girolamo, 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, T. Dooney, S. Doravari, O. Dorosh, W. J. D. Doyle, M. Drago, J. C. Driggers, M. Dubois, L. Dunn, U. Dupletsa, P. -A. Duverne, D. D'Urso, P. Dutta Roy, H. Duval, S. E. Dwyer, C. Eassa, M. Ebersold, T. Eckhardt, G. Eddolls, A. Effler, J. Eichholz, H. Einsle, M. Eisenmann, M. Emma, K. Endo, R. Enficiaud, L. Errico, R. Espinosa, M. Esposito, R. C. Essick, H. Estellés, T. Etzel, M. Evans, T. Evstafyeva, B. E. Ewing, J. M. Ezquiaga, F. Fabrizi, V. Fafone, S. Fairhurst, A. M. Farah, B. Farr, W. M. Farr, G. Favaro, M. Favata, M. Fays, M. Fazio, J. Feicht, M. M. Fejer, R. Felicetti, E. Fenyvesi, J. Fernandes, T. Fernandes, D. Fernando, S. Ferraiuolo, T. A. Ferreira, F. Fidecaro, P. Figura, A. Fiori, I. Fiori, M. Fishbach, R. P. Fisher, R. Fittipaldi, V. Fiumara, R. Flaminio, S. M. Fleischer, L. S. Fleming, E. Floden, H. Fong, J. A. Font, F. Fontinele-Nunes, C. Foo, B. Fornal, K. Franceschetti, F. Frappez, S. Frasca, F. Frasconi, J. P. Freed, Z. Frei, A. Freise, O. Freitas, R. Frey, W. Frischhertz, P. Fritschel, V. V. Frolov, G. G. Fronzé, M. Fuentes-Garcia, S. Fujii, T. Fujimori, P. Fulda, M. Fyffe, B. Gadre, J. R. Gair, S. Galaudage, V. Galdi, R. Gamba, A. Gamboa, S. Gamoji, D. Ganapathy, A. Ganguly, B. Garaventa, J. García-Bellido, C. García-Quirós, J. W. Gardner, K. A. Gardner, S. Garg, J. Gargiulo, X. Garrido, A. Garron, F. Garufi, P. A. Garver, C. Gasbarra, B. Gateley, F. Gautier, V. Gayathri, T. Gayer, G. Gemme, A. Gennai, V. Gennari, J. George, R. George, O. Gerberding, L. Gergely, Archisman Ghosh, Sayantan Ghosh, Shaon Ghosh, Shrobana Ghosh, Suprovo Ghosh, Tathagata Ghosh, J. A. Giaime, K. D. Giardina, D. R. Gibson, C. Gier, S. Gkaitatzis, J. Glanzer, F. Glotin, J. Godfrey, R. V. Godley, P. Godwin, A. S. Goettel, E. Goetz, J. Golomb, S. Gomez Lopez, B. Goncharov, G. González, P. Goodarzi, S. Goode, A. W. Goodwin-Jones, M. Gosselin, R. Gouaty, D. W. Gould, K. Govorkova, A. Grado, V. Graham, A. E. Granados, M. Granata, V. Granata, S. Gras, P. Grassia, J. Graves, C. Gray, R. Gray, G. Greco, A. C. Green, L. Green, S. M. Green, S. R. Green, C. Greenberg, A. M. Gretarsson, H. K. Griffin, D. Griffith, H. L. Griggs, G. Grignani, C. Grimaud, H. Grote, S. Grunewald, D. Guerra, D. Guetta, G. M. Guidi, A. R. Guimaraes, H. K. Gulati, F. Gulminelli, H. Guo, W. Guo, Y. Guo, Anuradha Gupta, I. Gupta, N. C. Gupta, S. K. Gupta, V. Gupta, N. Gupte, J. Gurs, N. Gutierrez, N. Guttman, F. Guzman, D. Haba, M. Haberland, S. Haino, E. D. Hall, E. Z. Hamilton, G. Hammond, M. Haney, J. Hanks, C. Hanna, M. D. Hannam, O. A. Hannuksela, A. G. Hanselman, H. Hansen, J. Hanson, S. Hanumasagar, R. Harada, A. R. Hardison, S. Harikumar, K. Haris, I. Harley-Trochimczyk, T. Harmark, J. Harms, G. M. Harry, I. W. Harry, J. Hart, B. Haskell, C. J. Haster, K. Haughian, H. Hayakawa, K. Hayama, M. C. Heintze, J. Heinze, 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, M. Heurs, A. L. Hewitt, J. Heynen, J. Heyns, S. Higginbotham, S. Hild, S. Hill, Y. Himemoto, N. Hirata, C. Hirose, D. Hofman, B. E. Hogan, N. A. Holland, I. J. Hollows, D. E. Holz, L. Honet, D. J. Horton-Bailey, J. Hough, S. Hourihane, N. T. Howard, E. J. Howell, C. G. Hoy, C. A. Hrishikesh, P. Hsi, H. -F. Hsieh, H. -Y. Hsieh, C. Hsiung, S. -H. Hsu, W. -F. Hsu, Q. Hu, H. Y. Huang, Y. Huang, Y. T. Huang, A. D. Huddart, B. Hughey, V. Hui, S. Husa, R. Huxford, L. Iampieri, G. A. Iandolo, M. Ianni, G. Iannone, J. Iascau, K. Ide, R. Iden, A. Ierardi, S. Ikeda, H. Imafuku, Y. Inoue, G. Iorio, P. Iosif, M. H. Iqbal, J. Irwin, R. Ishikawa, M. Isi, K. S. Isleif, Y. Itoh, M. Iwaya, B. R. Iyer, C. Jacquet, P. -E. Jacquet, T. Jacquot, S. J. Jadhav, S. P. Jadhav, M. Jain, T. Jain, A. L. James, K. Jani, J. Janquart, N. N. Janthalur, S. Jaraba, P. Jaranowski, R. Jaume, W. Javed, A. Jennings, M. Jensen, W. Jia, J. Jiang, H. -B. Jin, G. R. Johns, N. A. Johnson, M. C. Johnston, R. Johnston, N. Johny, D. H. Jones, D. I. Jones, R. Jones, H. E. Jose, P. Joshi, S. K. Joshi, G. Joubert, J. Ju, L. Ju, K. Jung, J. Junker, V. Juste, H. B. Kabagoz, T. Kajita, I. Kaku, V. Kalogera, M. Kalomenopoulos, M. Kamiizumi, N. Kanda, S. Kandhasamy, G. Kang, N. C. Kannachel, J. B. Kanner, S. A. KantiMahanty, S. J. Kapadia, D. P. Kapasi, M. Karthikeyan, M. Kasprzack, H. Kato, T. Kato, E. Katsavounidis, W. Katzman, R. Kaushik, K. Kawabe, R. Kawamoto, D. Keitel, L. J. Kemperman, J. Kennington, F. A. Kerkow, R. Kesharwani, J. S. Key, R. Khadela, S. Khadka, S. S. Khadkikar, F. Y. Khalili, F. Khan, T. Khanam, M. Khursheed, N. M. Khusid, W. Kiendrebeogo, N. Kijbunchoo, C. 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, E. J. Knox, N. Knust, K. Kobayashi, S. M. Koehlenbeck, G. Koekoek, K. Kohri, K. Kokeyama, S. Koley, P. Kolitsidou, A. E. Koloniari, K. Komori, A. K. H. Kong, A. Kontos, L. M. Koponen, M. Korobko, X. Kou, A. Koushik, N. Kouvatsos, M. Kovalam, T. Koyama, D. B. Kozak, S. L. Kranzhoff, V. Kringel, N. V. Krishnendu, S. Kroker, A. Królak, K. Kruska, J. Kubisz, G. Kuehn, S. Kulkarni, A. Kulur Ramamohan, Achal Kumar, Anil Kumar, Praveen Kumar, Prayush Kumar, Rahul Kumar, Rakesh Kumar, J. Kume, K. Kuns, N. Kuntimaddi, S. Kuroyanagi, S. Kuwahara, K. Kwak, K. Kwan, S. Kwon, G. Lacaille, D. Laghi, A. H. Laity, E. Lalande, M. Lalleman, P. C. Lalremruati, M. Landry, B. B. Lane, R. N. Lang, J. Lange, R. Langgin, B. Lantz, I. La Rosa, J. Larsen, A. Lartaux-Vollard, P. D. Lasky, J. Lawrence, M. Laxen, C. Lazarte, A. Lazzarini, C. Lazzaro, P. Leaci, L. Leali, Y. K. Lecoeuche, H. M. Lee, H. W. Lee, J. Lee, K. Lee, R. -K. Lee, R. Lee, Sungho Lee, Sunjae Lee, Y. Lee, I. N. Legred, J. Lehmann, L. Lehner, M. Le Jean, A. Lemaître, M. Lenti, M. Leonardi, M. Lequime, N. Leroy, M. Lesovsky, N. Letendre, M. Lethuillier, Y. Levin, K. Leyde, A. K. Y. Li, K. L. Li, T. G. F. Li, X. Li, Y. Li, Z. Li, A. Lihos, E. T. Lin, F. Lin, L. C. -C. Lin, Y. -C. Lin, C. Lindsay, S. D. Linker, A. Liu, G. C. Liu, Jian Liu, F. Llamas Villarreal, J. Llobera-Querol, R. K. L. Lo, J. -P. Locquet, S. C. G. Loggins, M. R. Loizou, L. T. London, A. Longo, D. Lopez, M. Lopez Portilla, A. Lorenzo-Medina, V. Loriette, M. Lormand, G. Losurdo, E. Lotti, T. P. Lott, J. D. Lough, H. A. Loughlin, C. O. Lousto, N. Low, N. Lu, L. Lucchesi, H. Lück, D. Lumaca, A. P. Lundgren, A. W. Lussier, R. Macas, M. MacInnis, D. M. Macleod, I. A. O. MacMillan, A. Macquet, K. Maeda, S. Maenaut, S. S. Magare, R. M. Magee, E. Maggio, R. Maggiore, M. Magnozzi, M. Mahesh, M. Maini, S. Majhi, E. Majorana, C. N. Makarem, 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, B. Mannix, G. L. Mansell, M. Manske, M. Mantovani, M. Mapelli, C. Marinelli, F. Marion, A. S. Markosyan, A. Markowitz, E. Maros, S. Marsat, F. Martelli, I. W. Martin, R. M. Martin, B. B. Martinez, D. A. Martinez, M. Martinez, V. Martinez, A. Martini, J. C. Martins, D. V. Martynov, E. J. Marx, L. Massaro, A. Masserot, M. Masso-Reid, S. Mastrogiovanni, T. Matcovich, M. Matiushechkina, L. Maurin, N. Mavalvala, N. Maxwell, G. McCarrol, R. McCarthy, D. E. McClelland, S. McCormick, L. McCuller, S. McEachin, C. McElhenny, G. I. McGhee, J. McGinn, K. B. M. McGowan, J. McIver, A. McLeod, I. McMahon, T. McRae, R. McTeague, D. Meacher, B. N. Meagher, R. Mechum, Q. Meijer, A. Melatos, C. S. Menoni, F. Mera, R. A. Mercer, L. Mereni, K. Merfeld, E. L. Merilh, J. R. Mérou, J. D. Merritt, M. Merzougui, C. Messick, B. Mestichelli, M. Meyer-Conde, F. Meylahn, A. Mhaske, A. Miani, H. Miao, C. Michel, Y. Michimura, H. Middleton, D. P. Mihaylov, S. J. Miller, M. Millhouse, E. Milotti, V. Milotti, Y. Minenkov, E. M. Minihan, Ll. M. Mir, L. Mirasola, M. Miravet-Tenés, C. -A. Miritescu, A. Mishra, C. Mishra, T. Mishra, A. L. Mitchell, J. G. Mitchell, S. Mitra, V. P. Mitrofanov, K. Mitsuhashi, R. Mittleman, O. Miyakawa, S. Miyoki, A. Miyoko, G. Mo, L. Mobilia, S. R. P. Mohapatra, S. R. Mohite, M. Molina-Ruiz, M. Mondin, M. Montani, C. J. Moore, D. Moraru, A. More, S. More, C. Moreno, E. A. Moreno, G. Moreno, A. Moreso Serra, S. Morisaki, Y. Moriwaki, G. Morras, A. Moscatello, M. Mould, B. Mours, C. M. Mow-Lowry, L. Muccillo, F. Muciaccia, D. Mukherjee, Samanwaya Mukherjee, Soma Mukherjee, Subroto Mukherjee, Suvodip Mukherjee, N. Mukund, A. Mullavey, H. Mullock, J. Mundi, C. L. Mungioli, M. Murakoshi, P. G. Murray, D. Nabari, S. L. Nadji, A. Nagar, N. Nagarajan, K. Nakagaki, K. Nakamura, H. Nakano, M. Nakano, D. Nanadoumgar-Lacroze, D. Nandi, V. Napolano, P. Narayan, I. Nardecchia, T. Narikawa, H. Narola, L. Naticchioni, R. K. Nayak, L. Negri, A. Nela, C. Nelle, A. Nelson, T. J. N. Nelson, M. Nery, A. Neunzert, S. Ng, L. Nguyen Quynh, S. A. Nichols, A. B. Nielsen, Y. Nishino, A. Nishizawa, S. Nissanke, W. Niu, F. Nocera, J. Noller, M. Norman, C. North, J. Novak, R. Nowicki, J. F. Nuño Siles, L. K. Nuttall, K. Obayashi, J. Oberling, J. O'Dell, E. Oelker, M. Oertel, G. Oganesyan, T. O'Hanlon, M. Ohashi, F. Ohme, R. Oliveri, R. Omer, B. O'Neal, M. Onishi, K. Oohara, B. O'Reilly, M. Orselli, R. O'Shaughnessy, S. O'Shea, S. Oshino, C. Osthelder, I. Ota, D. J. Ottaway, A. Ouzriat, H. Overmier, B. J. Owen, R. Ozaki, A. E. Pace, R. Pagano, M. A. Page, A. Pai, L. Paiella, A. Pal, S. Pal, M. A. Palaia, M. Pálfi, P. P. Palma, C. Palomba, P. Palud, H. Pan, J. Pan, K. C. Pan, P. K. Panda, Shiksha Pandey, Swadha Pandey, P. T. H. Pang, F. Pannarale, K. A. Pannone, B. C. Pant, F. H. Panther, M. Panzeri, F. Paoletti, A. Paolone, A. Papadopoulos, E. E. Papalexakis, L. Papalini, G. Papigkiotis, A. Paquis, A. Parisi, B. -J. Park, J. Park, W. Parker, G. Pascale, D. Pascucci, A. Pasqualetti, R. Passaquieti, L. Passenger, D. Passuello, O. Patane, A. V. Patel, D. 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, M. D. Penuliar, A. Perego, Z. Pereira, C. Périgois, G. Perna, A. Perreca, J. Perret, S. Perriès, J. W. Perry, D. Pesios, S. Peters, S. Petracca, C. Petrillo, H. P. Pfeiffer, H. Pham, K. A. Pham, K. S. Phukon, H. Phurailatpam, M. Piarulli, L. Piccari, O. J. Piccinni, M. Pichot, M. Piendibene, F. Piergiovanni, L. Pierini, G. Pierra, V. Pierro, M. Pietrzak, M. Pillas, F. Pilo, L. Pinard, I. M. Pinto, M. Pinto, B. J. Piotrzkowski, M. Pirello, M. D. Pitkin, A. Placidi, E. Placidi, M. L. Planas, W. Plastino, C. Plunkett, R. Poggiani, E. Polini, J. Pomper, L. Pompili, J. Poon, E. Porcelli, E. K. Porter, C. Posnansky, R. Poulton, J. Powell, G. S. Prabhu, M. Pracchia, B. K. Pradhan, T. Pradier, A. K. Prajapati, K. Prasai, R. Prasanna, P. Prasia, G. Pratten, G. Principe, G. A. Prodi, P. Prosperi, P. Prosposito, A. C. Providence, A. Puecher, J. Pullin, P. Puppo, M. Pürrer, H. Qi, J. Qin, G. Quéméner, V. Quetschke, P. J. Quinonez, N. Qutob, R. Rading, I. Rainho, S. Raja, C. Rajan, B. Rajbhandari, K. E. Ramirez, F. A. Ramis Vidal, M. Ramos Arevalo, A. Ramos-Buades, S. Ranjan, K. Ransom, P. Rapagnani, B. Ratto, A. Ravichandran, A. Ray, V. Raymond, M. Razzano, J. Read, T. Regimbau, S. Reid, C. Reissel, D. H. Reitze, A. I. Renzini, B. Revenu, A. Revilla Peña, R. Reyes, L. Ricca, F. Ricci, M. Ricci, A. Ricciardone, J. Rice, J. W. Richardson, M. L. Richardson, A. Rijal, K. Riles, H. K. Riley, S. Rinaldi, J. Rittmeyer, C. Robertson, F. Robinet, M. Robinson, A. Rocchi, L. Rolland, J. G. Rollins, A. E. Romano, R. Romano, A. Romero, I. M. Romero-Shaw, J. H. Romie, S. Ronchini, T. J. Roocke, L. Rosa, T. J. Rosauer, C. A. Rose, D. Rosińska, M. P. Ross, M. Rossello-Sastre, S. Rowan, S. K. Roy, S. Roy, D. Rozza, P. Ruggi, N. Ruhama, E. Ruiz Morales, K. Ruiz-Rocha, S. Sachdev, T. Sadecki, P. Saffarieh, S. Safi-Harb, M. R. Sah, S. Saha, T. Sainrat, S. Sajith Menon, K. Sakai, Y. Sakai, M. Sakellariadou, S. Sakon, O. S. Salafia, F. Salces-Carcoba, L. Salconi, M. Saleem, F. Salemi, M. Sallé, S. U. Salunkhe, S. Salvador, A. Salvarese, A. Samajdar, A. Sanchez, E. J. Sanchez, L. E. Sanchez, N. Sanchis-Gual, J. R. Sanders, E. M. Sänger, F. Santoliquido, F. Sarandrea, T. R. Saravanan, N. Sarin, P. Sarkar, A. Sasli, P. Sassi, B. Sassolas, B. S. Sathyaprakash, R. Sato, S. Sato, Yukino Sato, Yu Sato, O. Sauter, R. L. Savage, T. Sawada, H. L. Sawant, S. Sayah, V. Scacco, D. Schaetzl, M. Scheel, A. Schiebelbein, M. G. Schiworski, P. Schmidt, S. Schmidt, R. Schnabel, M. Schneewind, R. M. S. Schofield, K. Schouteden, B. W. Schulte, 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, A. S. Sengupta, E. G. Seo, J. W. Seo, V. Sequino, M. Serra, A. Sevrin, T. Shaffer, U. S. Shah, M. A. Shaikh, L. Shao, A. K. Sharma, Preeti Sharma, Prianka Sharma, Ritwik Sharma, S. Sharma Chaudhary, P. Shawhan, N. S. Shcheblanov, E. Sheridan, Z. -H. Shi, M. Shikauchi, R. Shimomura, H. Shinkai, S. Shirke, D. H. Shoemaker, D. M. Shoemaker, R. W. Short, S. ShyamSundar, A. Sider, H. Siegel, D. Sigg, L. Silenzi, L. Silvestri, M. Simmonds, L. P. Singer, Amitesh Singh, Anika Singh, D. Singh, N. Singh, S. Singh, A. M. Sintes, V. Sipala, V. Skliris, B. J. J. Slagmolen, D. A. Slater, T. J. Slaven-Blair, J. Smetana, J. R. Smith, L. Smith, R. J. E. Smith, W. J. Smith, S. Soares de Albuquerque Filho, M. Soares-Santos, K. Somiya, I. Song, S. Soni, V. Sordini, F. Sorrentino, H. Sotani, F. Spada, V. Spagnuolo, A. P. Spencer, P. Spinicelli, A. K. Srivastava, F. Stachurski, C. J. Stark, D. A. Steer, N. Steinle, J. Steinlechner, S. Steinlechner, N. Stergioulas, P. Stevens, M. StPierre, M. D. Strong, A. Strunk, A. L. Stuver, M. Suchenek, S. Sudhagar, Y. Sudo, N. Sueltmann, L. Suleiman, K. D. Sullivan, J. Sun, L. Sun, S. Sunil, J. Suresh, B. J. Sutton, P. J. Sutton, K. Suzuki, M. Suzuki, B. L. Swinkels, A. Syx, M. J. Szczepańczyk, P. Szewczyk, M. Tacca, H. Tagoshi, K. Takada, H. Takahashi, R. Takahashi, A. Takamori, S. Takano, H. Takeda, K. Takeshita, I. Takimoto Schmiegelow, M. Takou-Ayaoh, 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, C. Taranto, A. Taruya, J. D. Tasson, J. G. Tau, D. Tellez, R. Tenorio, H. Themann, A. Theodoropoulos, M. P. Thirugnanasambandam, L. M. Thomas, M. Thomas, P. Thomas, J. E. Thompson, S. R. Thondapu, K. A. Thorne, E. Thrane, J. Tissino, A. Tiwari, Pawan Tiwari, Praveer Tiwari, S. Tiwari, V. Tiwari, M. R. Todd, M. Toffano, A. M. Toivonen, K. Toland, A. E. Tolley, T. Tomaru, V. Tommasini, T. Tomura, H. Tong, C. Tong-Yu, A. Torres-Forné, C. I. Torrie, I. Tosta e Melo, E. Tournefier, M. Trad Nery, K. Tran, A. Trapananti, R. Travaglini, F. Travasso, G. Traylor, M. Trevor, M. C. Tringali, A. Tripathee, G. Troian, A. Trovato, L. Trozzo, R. J. Trudeau, T. Tsang, S. Tsuchida, L. Tsukada, K. Turbang, M. Turconi, C. Turski, H. Ubach, N. Uchikata, T. Uchiyama, R. P. Udall, T. Uehara, K. Ueno, V. Undheim, L. E. Uronen, T. Ushiba, M. Vacatello, H. Vahlbruch, N. Vaidya, G. Vajente, A. Vajpeyi, J. Valencia, M. Valentini, S. A. Vallejo-Peña, S. Vallero, V. Valsan, M. van Dael, E. Van den Bossche, J. F. J. van den Brand, C. Van Den Broeck, 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, M. VanKeuren, J. Vanosky, N. van Remortel, M. Vardaro, A. F. Vargas, V. Varma, A. N. Vazquez, A. Vecchio, G. Vedovato, J. Veitch, P. J. Veitch, S. Venikoudis, R. C. Venterea, P. Verdier, M. Vereecken, D. Verkindt, B. Verma, Y. Verma, S. M. Vermeulen, F. Vetrano, A. Veutro, A. Viceré, S. Vidyant, A. D. Viets, A. Vijaykumar, A. Vilkha, N. Villanueva Espinosa, V. Villa-Ortega, E. T. Vincent, J. -Y. Vinet, S. Viret, S. Vitale, 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, E. J. Wang, H. Wang, J. Z. Wang, W. H. Wang, Y. F. Wang, G. Waratkar, 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, J. T. Whelan, B. F. Whiting, C. Whittle, E. G. Wickens, D. Wilken, A. T. Wilkin, B. M. Williams, D. Williams, M. J. Williams, N. S. Williams, J. L. Willis, B. Willke, M. Wils, L. Wilson, C. W. Winborn, J. Winterflood, C. C. Wipf, G. Woan, J. Woehler, N. E. Wolfe, H. T. Wong, I. C. F. Wong, K. Wong, T. Wouters, J. L. Wright, M. Wright, B. Wu, C. Wu, D. S. Wu, H. Wu, K. Wu, Q. Wu, Y. 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, K. Z. Yang, Y. Yang, Z. Yarbrough, J. Yebana, S. -W. Yeh, A. B. Yelikar, X. Yin, J. Yokoyama, T. Yokozawa, S. Yuan, H. Yuzurihara, M. Zanolin, M. Zeeshan, T. Zelenova, J. -P. Zendri, M. Zeoli, M. Zerrad, M. Zevin, L. Zhang, N. Zhang, R. Zhang, T. Zhang, C. Zhao, Yue Zhao, Yuhang Zhao, Z. -C. Zhao, Y. Zheng, H. Zhong, H. Zhou, H. O. Zhu, Z. -H. Zhu, A. B. Zimmerman, L. Zimmermann, M. E. Zucker, J. Zweizig,

Comments: 26 pages. The version updates Table 3, updates the author list, removes one figure, and updates some text for clarity and grammar

Subjects: gr-qc astro-ph.HE

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

LIGO, Virgo, and KAGRA form a network of gravitational-wave observatories. Data and analysis results from this network are made publicly available through the Gravitational Wave Open Science Center. This paper describes open data from this network, including the addition of data from the first part of the fourth observing run and selected periods from the preceding engineering run, collected from 2023 May to 2024 January. The public dataset includes calibrated strain time series for each instrument, data from additional channels used for noise subtraction and detector characterization, and analysis data products from version 4.0 of the Gravitational-Wave Transient Catalog.

[abstract 5 / 37] Yes (score: 5)
arXiv:2510.26986 [pdf, ps, other]

Title: MRX: A differentiable 3D MHD equilibrium solver without nested flux surfaces

Authors: Tobias Blickhan, Julianne Stratton, Alan A. Kaptanoglu,

Comments:

Subjects: physics.comp-ph physics.plasm-ph

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

This article introduces a new 3D MAGNETohydrodynamic (MHD) equilibrium solver, MRX, based on relaxation of a MAGNETic field to a lower energy equilibrium state via admissible variations. We describe the mathematical theory behind this method and discuss what can be transferred to the fully discrete setting of a relaxation code. Our code is designed to address a number of traditional challenges to 3D MHD equilibrium solvers: enforcing physical constraints such as divergence-free MAGNETic field, high-order convergence, handling strongly shaped polar geometries, and controlling topology changes of the MAGNETic field. Building on the JAX framework, we address questions of computational efficiency on modern computing architectures, user accessibility, and differentiability at each step. The solver is verified on manufactured vacuum solutions and against a VMEC equilibrium of a quasi-axisymmetric stellarator. It is further demonstrated on a finite-beta NCSX configuration, where we study h and p refinement, preservation of helicity, RECONNECTion events and seeded island chains. Finally, an inexact Newton method enables the computation of high-resolution finite-beta equilibria with islands and chaos in minutes on a single GPU.

[abstract 6 / 37] Yes (score: 5)
arXiv:2609.19259 [pdf, ps, other]

Title: On the Clustering Bias of Unresolved Gamma-Ray Sources

Authors: Bhashin A. Thakore, Marco Regis, Michela Negro, Stefano Camera, Daniel Gruen, Nicolao Fornengo, Aaron J. Roodman,

Comments: 8 pages, 9 figures

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

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

The Unresolved $γ$-Ray Background (UGRB) encodes the collective emission of source populations that are too faint to be detected individually, and its cross-correlation with tracers of the large-scale structure has emerged as a powerful tool to characterize those populations. In this work, we analyze the weak-lensing--UGRB cross-correlation using a reference BLAZAR model. By modeling the relation between BLAZAR $γ$-ray luminosity and host-halo mass, we infer the average linear bias $\langle b(z) \rangle$ and host-halo mass $\langle M(z) \rangle$ of the unresolved BLAZAR population. We find that the signal is dominated by moderately biased sources, with $\langle b \rangle \gtrsim 2$ at $z\simeq 1$, hosted by halos with $\langle M \rangle \sim \mathcal{O}(10^{13}\,M_\odot)$. Repeating the analysis with a misaligned-AGN model yields consistent bias values, indicating that the result is determined by the clustering properties of the UGRB rather than by the details of the $γ$-ray source model.

[abstract 7 / 37] Yes (score: 5)
arXiv:2609.19459 [pdf, ps, other]

Title: Extreme Enrichment at Cosmic Dawn: Three FeII-Strong Quasars at z > 6 from the JWST Aether survey

Authors: Anniek J. Gloudemans, Emanuele Paolo Farina, Roberto Decarli, Klaudia Protušová, Fabrizio Arrigoni Battaia, Eduardo Bañados, Aaron J. Barth, Silvia Belladitta, Manuela Bischetti, Hyunseop Choi, Dominika Ďurovčíková, Anna-Christina Eilers, Simona Gallerani, Thales A. Gutcke, Luca Ighina, Brian C. Lemaux, Federica Loiacono, Yoshiki Matsuoka, Chiara Mazzucchelli, Silvia Onorato, Hyewon Suh, Fabian Walter, Feige Wang, Julien Wolf, Jinyi Yang,

Comments: Accepted for publication in The Astrophysical Journal, 19 pages, 11 figures

Subjects: astro-ph.GA

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

We present three outliers on the QUASAR main sequence at z>6, as revealed by JWST/NIRSpec IFU observations from the Aether survey, a program targeting ~200 QUASARs at cosmic dawn. The QUASARs, J0216-5226, J0320-3521, and J1429+5447, exhibit exceptionally strong FeII emission and weak H$β$ and [OIII] lines, indicating rapid chemical enrichment within the first Gyr of cosmic history. Their FeII strengths ($R_{\rm{FeII},\lambda4570} \equiv \rm{EW}_{\rm{FeII}}/\rm{EW}_{\rm{H}β}$) range between ~2.5-3.6, placing them among the top ~3% of SDSS QUASARs at ($0\lesssim z\lesssim 1$). The H$α$ emission lines of J0216-5226 and J1429+5447 imply BLACK HOLE masses of $\sim1-7\times10^9$ M$_{\odot}$ with $λ_{\rm{Edd}}\sim0.1-0.6$, comparable to typical high-z QUASARs, although virial BLACK HOLE masses may be systematically overestimated in strong FeII emitters. In contrast, J0320-3521 hosts a lower mass BLACK HOLE of $\sim0.2-2\times10^9$ M$_{\odot}$, suggesting possible super-Eddington rate accretion with $λ_{\rm{Edd}}$~0.5-6.0. The IFU data of J0320-3521 reveal a distinct emission-line region at a projected distance of ~1.5 kpc, consistent with either an interacting companion or ionized gas associated to the QUASAR. We further identify a complex environment around J1429+5447, including two candidate companion galaxies or extended ionized gas structures. These QUASARs with bright emission-line regions, J0320-3521 and J1429+5447, are radio-loud sources, while J0216-5226 remains undetected in radio ($R_{5\rm{GHz,} \,3σ}\lesssim4$). Together, these results confirm previous findings that highly enriched, rapidly growing BLACK HOLEs were already in place at cosmic dawn. Despite the small sample size, our results further highlight the diversity in environment and radio-JET properties among QUASARs that otherwise share the same extreme region of the QUASAR fundamental plane.

[abstract 8 / 37] Yes (score: 4)
arXiv:2604.19534 [pdf, ps, other]

Title: The swept-back multipolar MAGNETic field of neutron stars: Application to NICER MSP J0030+0451

Authors: Anu Kundu, Constantinos Kalapotharakos, Zorawar Wadiasingh, Greg Olmschenk, Wendy F. Wallace, Alice K. Harding, Christo Venter, Demosthenes Kazanas,

Comments: The Astrophysical Journal, 2026, Volume 1008, Issue 2, id.215, 23 pp. Interactive figures are available in the published version

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

NICER observations of millisecond pulsars (MSPs) suggest that non-dipolar MAGNETic fields are required to explain their surface X-ray hotspots. C. Kalapotharakos et al. modeled the NICER light curve of MSP J$0030+0451$ (J$0030$) using a static vacuum offset dipole-plus-quadrupole field and corresponding force-free (FF) solutions to jointly reproduce the X-ray and FERMI-LAT $γ$-ray emission. We substitute their static vacuum field model with a more realistic swept-back configuration that accounts for rotational effects. This field more closely resembles the corresponding FF solutions, making it a more physically motivated choice for future multiwavelength modeling. We adopt a centered swept-back vacuum multipolar MAGNETic field (SVM2F; J. Pétri), expressed as a complete expansion in vector spherical harmonics, enabling flexible descriptions of arbitrary MAGNETic field geometries. We introduce a metric to quantify the complexity among different field prescriptions, illustrated for the static offset vacuum field. To efficiently explore parameter space, we train a neural network surrogate (G. Olmschenk et al.) on SVM2F light curves including components up to the octupole, accelerating Markov chain Monte Carlo sampling by $\sim 10^3$ compared to direct physical model evaluations. Applying this framework to J$0030$, we constrain the field parameter space and find that a centered swept-back multipolar field including terms up to the octupole adequately reproduces the bolometric thermal X-ray light curve. Our study highlights the importance and inherent complexity of prescribing different multipolar MAGNETic field models for rotating stars, and can be extended to other MSPs to ultimately constrain the masses and radii of neutron stars, and hence their equation of state.

[abstract 9 / 37] Yes (score: 4)
arXiv:2607.00360 [pdf, ps, other]

Title: An equal mass ratio supermassive binary BLACK HOLEs in Q J0158-4325 with periodic microlensing signature?

Authors: Changshuo Yan, Youjun Lu, Junqiang Ge, Erlin Qiao,

Comments: 13 pages, 12 figures

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

This study aims to test whether a supermassive binary BLACK HOLE (SMBBH) system with a triple-disk accretion structure can explain the observed $\sim$173-day periodic microlensing variations and spectral energy distribution (SED) of the gravitationally lensed QUASAR Q J0158-4325. We construct a triple-disk model for the SMBBH system, incorporating realistic accretion disk structures, orbital motion, and microlensing effects. The model is used to simulate optical and X-ray microlensing light curves and SEDs, which are compared with long-term optical monitoring, X-ray observations, and UV-optical spectra from HST and XSHOOTER. Bayesian analysis and MCMC fitting are applied to constrain model parameters. The model successfully reproduces the periodic microlensing variations. Combined light curve and SED fitting favor a high mass ratio ($q>0.5$) SMBBH system with total mass $\sim 10^{9.5}M_\odot$, and nearly equal-mass binaries ($q\sim1$) provides the best agreement with both the optical/UV spectrum and the microlensing signal. This model predicts larger X-ray microlensing amplitudes than in the optical, but, the available X-ray observations lack the precision needed to place strong constraints. We emphasize the need for future high-cadence monitoring to resolve remaining uncertainties. This study demonstrates the effectiveness of combining multi-wavelength microlensing signatures with spectral modeling to provide robust constraints on SMBBH systems, with the developed framework applicable to other lensed QUASARs for identifying and characterizing candidate SMBBHs.

[abstract 10 / 37] Yes (score: 4)
arXiv:2609.19281 [pdf, ps, other]

Title: Hydrodynamic Simulations of Eccentric Black Hole Encounters in AGN Discs

Authors: Andrew Imai, Henry Whitehead, Bence Kocsis,

Comments: 15 pages, 10 figures, submitted to MNRAS

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

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

We investigate close encounters between stellar-mass BLACK HOLEs (BHs) in the gaseous discs of ACTIVE GALACTIC NUCLEi (AGNs), during which binary BLACK HOLEs (BBHs) may form. We perform a suite of 483 2D adiabatic viscous hydrodynamic simulations within a shearing box prescription using the Eulerian grid code Athena++. We co-evolve the two embedded BHs with the gas. To probe the dependence of capture on non-circular initial conditions, we vary the initial radial separation $b$, the eccentricity $e$ of one of the stellar BHs around the central supermassive BLACK HOLE, and the eccentric phase angle $ϕ_e$. We consider eccentricities from $e=0$ to $e=0.1$ and compare them with the local disc aspect ratio $h=H/R_0\simeq0.005$. We find that small eccentricities shift the capture window in the parameter space. Eccentricities of order the disc aspect ratio, in particular $e\sim h$--$2h$, produce successful captures at initial separations that do not capture in the circular models. By contrast, systems with $e \gg h$ retain less gas before encounter and have lower capture fractions across the sampled parameter grid. We find that the first periapsis distance is a useful predictor of direct capture. Predicting direct capture for $r_{\rm p}<0.1r_H$ correctly classifies $92.7\%$ of Hill sphere encounters. The Hill sphere gas mass helps identify gas-poor failures, but provides no clear additional capture boundary within this suite, in which the initial disc density, temperature, and viscosity parameter are held fixed. Pre-encounter eccentricity modifies gas-assisted BBH formation through its combined effects on the first-encounter geometry and the gas reservoir available for orbital energy dissipation.

[abstract 11 / 37] Yes (score: 4)
arXiv:2609.20046 [pdf, ps, other]

Title: The 2025.6 X-ray Minimum of Eta Carinae

Authors: Amit Kashi, Noam Soker,

Comments: Submitted

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

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

We present observations of the recent 2025.6 X-ray minimum and recovery of $η$~Carinae, obtained with NICER/XTI, SWIFT/XRT, XRISM/Xtend, and Chandra/HRC-I. We construct light curves in the soft (0.5--2 keV) and hard (2--10 keV) bands and derive hardness ratios. The X-ray emission reached its minimum about 10 days earlier than in the previous five cycles. As in previous events, the spectrum softened during the decline, while the X-ray luminosity varied on short timescales. These findings strengthen the conclusion that enhanced line-of-sight absorption, such as that expected during an eclipse, does not have a significant role in producing the spectroscopic event. Instead, they indicate that the X-ray decline is caused by stochastic variations and instabilities in the two stellar winds and their interaction, destruction of the colliding winds region, and accretion of primary wind onto the secondary. The main process behind the deep X-ray minimum near periastron is the accretion of mass lost by the primary star onto the secondary star. Accretion at periastron passages in $η$ Carinae implies that accretion occurred at much higher rates during the nineteenth-century Great and Lesser Eruptions, when the primary star lost mass at much higher rates. Such accretion likely launches JETs. The broader implication is that accretion events in binary systems, possibly with JET launching, power other luminous blue variable giant eruptions and intermediate-luminosity optical transients.

[abstract 12 / 37] Yes (score: 4)
arXiv:2609.20787 [pdf, ps, other]

Title: A systematic search for long GRBs without SUPERNOVAe: global properties and rate of events

Authors: Yu-Han Yang, Eleonora Troja, Nicolas Monsalves, Massine El Kabir, Narjes Shahamat Dehsorkh, Hira Waseem,

Comments: 24 pages, 11 figures, 1 interactive figure, 2 tables; submitted to ApJ; comments welcome

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Some long duration GAMMA-RAY BURSTs (LGRBs) are not associated with bright SUPERNOVAe (SNe), indicating that their explosion mechanism differs from the traditional collapsar channel. SN-less LGRBs are rare, thus it remains unclear whether they are sporadic outliers or a substantial component of the GRB population. In this work, we use two decades of SWIFT observations to conduct a systematic search for nearby ($z\lesssim$0.35) LGRBs without a confirmed SN association. Our analysis reveals a heterogeneous population linked, in part, to star-forming or dusty environments and, in part, to quiescent galaxies. Through the analysis of their high-energy properties, afterglows, and environments, we identify a sample of LGRBs with robust SN limits and distance scales, more than doubling the number of candidate SN-less events. From our fiducial sample, we derive a volumetric rate, not corrected for beaming, of $R = (0.5 \pm 0.2) {\rm~Gpc^{-3}\ yr^{-1}}$, comparable to the apparent rate of short duration GRBs (SGRBs) and standard LGRBs with SNe with luminosities $L \gtrsim\,10^{50}\,{\rm erg\,s^{-1}}$. For plausible beaming factors, the inferred rate of SN-less LGRBs is consistent with several compact binary merger channels, although the allowed parameter space is already narrow if the entire population is attributed to a single progenitor channel. Owing to the small number of candidate events and the uncertainties in their distance scale, our sample leaves the low-luminosity tail unconstrained. A larger sample will be needed to determine whether they are the faint tail of known progenitor channels or evidence of a distinct route to RELATIVISTIC explosions.

[abstract 13 / 37] (score: 3)
arXiv:2606.25806 [pdf, ps, other]

Title: Study for curvature radiation and MAGNETic pair creation process on polar-cap region of MAGNETic white dwarf

Authors: Bingyan Wang, Jumpei Takata,

Comments: 18 pages, 8 figures, submitted to ApJ

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Rapidly rotating, strongly MAGNETized white dwarfs (WDs) have been proposed as potential sites of rotation-powered activity analogous to that of a neutron star pulsar. In this study, we investigate particle acceleration, radiation processes, pair creation and resulting SYNCHROTRON radiation in the polar cap acceleration region. Within the framework of the space-charge-limited flow model, we examine how these processes depend on the spin period and surface MAGNETic field using both one-dimensional numerical calculations and analytical estimates. To explore the impact of the MAGNETic field geometry on the accelerating process, we consider both a pure dipole field and a combination of dipole and quadrupole fields. The inclusion of a quadrupole component reduces the curvature radius of the MAGNETic field lines, and significantly enhances the accelerating field, leading to more efficient radiation and pair creation processes. Using this framework, we evaluate the WD death line with a more consistent treatment of the relevant physical processes than the previous studies. We find that the pair creation process can occur for spin periods $P\lesssim100$~s, when the dipole field strength $B_{*,d}\lesssim10^{10}$~G, indicating that pair creation is difficult to sustain in currently known MAGNETic WDs. We discuss the implications of our model for rotation-powered activity in rapidly spinning isolated MAGNETic WDs and for the possible WD interpretation of long-period radio transients.

[abstract 14 / 37] (score: 3)
arXiv:2607.20614 [pdf, ps, other]

Title: Gravitational Lensing Predictions from Wave Simulations of Fuzzy Dark Matter

Authors: Jiajun Zhou, Zhengxiang Li, Amruth Alfred, Ran Gao, Jeremy Lim, Zong-Hong Zhu,

Comments: 18 pages, 9 figures; Published in ApJL.Volume 1008, Number 2. Comments are welcome

Subjects: astro-ph.CO

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

In the cold DARK MATTER paradigm, ultra-light particles are emerging as strong contenders to conventional massive particles. A unique prediction of DARK MATTER comprising such ultra-light particles, known as fuzzy DARK MATTER (FDM), is the presence of strong density modulations throughout galactic halos due to wave interference, which -- when approximated by a Gaussian random field (GRF) -- have been proposed to account for the inability to reproduce the observed positions (when measured at sufficient precisions) and flux ratios of multiply-lensed images of QUASARs. Here, we predict for the first time the properties of gravitationally lensed images generated from 3-D density fields obtained by wave simulations that directly evolve the Schrödinger--Poisson equations. Using a novel framework to project these evolved density fields along various axes of the 3-D halo, we obtain the distribution of perturbations to the positions of lensed images. As an exacting test, we find that particles of mass $10^{-22}$ eV can reproduce the positions of the quadruply-lensed radio JETs in system HS 0810+2554 to a level better than that of either the GRF approximation or, to a greater extent, an NFW best-fit solution, both of which rely on accurately capturing the global 3-D density field of DARK MATTER halos. Our work highlights the importance of wave simulations for making accurate FDM lensing predictions and the potential for high-resolution observations of lensed systems to serve as a direct probe of the nature of DARK MATTER.

[abstract 15 / 37] (score: 3)
arXiv:2609.19461 [pdf, ps, other]

Title: Energy redistribution during 2D oscillatory RECONNECTion

Authors: Luiz A. C. A. Schiavo, Jordan Talbot, Gert J. J. Botha, Ben Snow, Daniel Johnson, Madeleine L. Combrinck, James A. McLaughlin,

Comments:

Subjects: astro-ph.SR

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

Magnetic RECONNECTion is a fundamental energy release mechanism in solar and space plasmas. However, the distribution of released MAGNETic energy among kinetic and internal (thermal) energy during time-dependent RECONNECTion remains largely unexplored. This work aims to study energy conversion in MAGNETohydrodynamics via oscillatory RECONNECTion (OR) at a 2D MAGNETic null point. Using a shock-capturing code, we identify three families of shocks: termination shocks, slow-mode deflection shocks, and Petschek-like shocks (even with uniform resistivity). We measure the time-dependent RECONNECTion rate, finding a peak of $R \approx 0.1$, consistent with a fast RECONNECTion regime. For the first time, we track the energy conversion pathways between MAGNETic, kinetic and internal energy across the time-dependent RECONNECTing system. We find energy exchange is strongly region dependent, with shock locations dominating over the diffusion region. In the classical incompressible steady-state RECONNECTion models, the MAGNETic energy is fully converted into internal and kinetic energy. In contrast, we find that in compressible time-dependent RECONNECTion, the interchange between kinetic and internal energy dominates the system (due to the inclusion of plasma compressibility).

[abstract 16 / 37] (score: 3)
arXiv:2609.19566 [pdf, ps, other]

Title: Multi-thermal Structure of Solar Jets based on Combined EUV and Ha Observations

Authors: Lei Huang, Yang Guo, Zining Ren, Mingde Ding,

Comments: 16 pages, 8 figures, and 2 tables. Accepted for publication in ApJ

Subjects: astro-ph.SR

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

This study investigates the multi-thermal structure of solar JETs by combining extreme ultra-violet (EUV) and Ha observations, addressing whether cool and hot components originate from the same JET, their morphological similarities and differences, and the role of mini-filaments. We analyze 70 JET events simultaneously observed by Atmospheric Imaging Assembly (AIA) and Chinese Ha Solar Explorer (CHASE) from 2023 May 25 to 2026 January 15. The events are classified into four types based on whether or not there are significant differences between the two wavebands in terms of length and width; nonlinear force-free field extrapolations are applied to examine MAGNETic fields. We find that the cool and hot components correspond to different temperature parts of a unified JET, showing spatiotemporal coincidence and kinematic synchronization. Morphologically, 30% show no significant difference in length/width, 37% differ in one dimension, and 33% differ in both. About 80% involve mini-filament eruptions; JETs with filaments more often exhibit morphological differences (filament non-expansion, hot shell thickness, insufficient kinetic energy, or material rarefaction). In contrast, JETs without filaments tend to show consistent morphologies; when discrepancies occur, they are mainly linked to small MAGNETic field curvature, which reduces MAGNETic tension and leads to less acceleration of cool material. These results highlight the complex interaction between thermal, dynamic, and MAGNETic factors in shaping JET morphology.

[abstract 17 / 37] (score: 3)
arXiv:2609.19741 [pdf, ps, other]

Title: Polarization of Synchrotron Emission from Rotation Powered Pulsars

Authors: Seima Saeki, Shota Kisaka, Jumpei Takata,

Comments: 15 pages, 10 figures, 1 table. Accepted for publication in ApJ

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

With the launch of the Imaging X-ray Polarimeter Explorer in 2021, recent observations have provided X-ray POLARIZATION data for several rotation-powered pulsars. To fully exploit these data, it is important to better understand the relationship between POLARIZATION properties and the MAGNETospheric structure. In this paper, we investigate POLARIZATION properties in the outer gap model, incorporating both outward emission and inward emission toward the rotation axis, which has not been considered previously. We find that the POLARIZATION position angle varies at the intensity peaks, typically accompanied by a high POLARIZATION degree, as is in the case for outward emission. Moreover, the variation in the POLARIZATION position angle tends to exceed 50 degrees when the intensity peaks of outward and inward emissions overlap, compared to cases with only outward emission. We compare the POLARIZATION model including inward emission with IXPE observations. For example, for PSR B1509-58 where inward emission is proposed to be dominant in the outer gap model, we find that observed PA swing prefers a line of sight from the southern hemisphere rather than the northern hemisphere.

[abstract 18 / 37] (score: 3)
arXiv:2609.20417 [pdf, ps, other]

Title: Gaia method paper: an algorithm to detect flare events in Gaia time-series

Authors: E. Distefano, A. C. Lanzafame, A. F. Lanza, S. Messina, I. Pagano, M. Audard, G. Jevardat de Fombelle, B. Holl, I. Lecoeur-Taibi, N. Mowlavi, K. Nienartowicz, L. Rimoldini, D. W. Evans, M. Riello, P. García-Lario, P. Gavra, L. Eyer,

Comments: Accepeted for pubblication in Astronomy and Astrophysics, 17 pages, 16 figures

Subjects: astro-ph.SR

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

The third Gaia data release (GDR3) includes the gdr3_rotmod catalogue of 474026 stars with variability that is attributed to MAGNETic activity analogous to that observed in the Sun, arising from rotational modulation induced by spots and faculae. These stars are therefore expected to exhibit flaring activity driven by MAGNETic RECONNECTion processes. We aim to demonstrate that stellar flares can be reliably identified and characterised in the sparsely sampled \gaia\ photometric time series. We developed and validated a dedicated flare-detection pipeline that exploits the simultaneous multi-band photometry in the $G$, $G_{\rm BP}$, and $G_{\rm RP}$ bands. The algorithm identifies outliers associated with a concurrent increase in brightness and blueing of the stellar colour, and applies consistency criteria to distinguish genuine flare events from instrumental or calibration artefacts. Applying this method to the gdr3_rotmod catalogue, we detect 3217 flares occurring on 2818 stars out of 474026 analysed sources. All events are provided in a dedicated catalogue together with their photometric amplitudes. For a subset of 348 flares, we estimate an effective temperature using a black-body approximation, and we identify 29 hyper-flares with amplitudes $A(G)\ge0.75$ mag, which occur preferentially in M dwarfs. Despite the sparse temporal sampling of Gaia, our results demonstrate that its multi-band photometry and spectrophotometric information enable the robust detection of flares and the basic characterisation of their properties across an all-sky stellar sample. This work establishes the methodological foundation for future Gaia flare catalogues and provides a homogeneous, complementary view of stellar flaring activity alongside high-cadence missions such as Kepler and TESS.

[abstract 19 / 37] (score: 2)
arXiv:2512.24978 [pdf, ps, other]

Title: Multi-Frequency Study of FRB20201124A with the uGMRT

Authors: C. Dudeja, J. Roy, U. Panda, S. Bhattacharyya,

Comments: 26 pages, 13 figures, 2 tables. Accepted for publication in ApJ

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

We present results from a monitoring campaign of FRB 20201124A using the uGMRT during its active phase between MJD 59342 and 59362. Simultaneous observations in Band 4 (550-950 MHz) and Band 5 (1060-1460 MHz) provide a uniform view of the source activity. The burst activity exhibits a frequency-dependent evolution, with the last Band-5 burst detected on MJD 59358, while Band-4 activity persisted until MJD 59362. We identified burst pairs in the simultaneously observed Band-4 and Band-5 data, with time separations of 31.8 ms and 52.3 ms. These separations are comparable to the short-timescale component of the waiting-time distribution, which peaks at $\sim$ 60 ms, suggesting that the multi-band burst pairs may be associated with the same short-timescale clustering process. Contemporaneous FAST observations detected the Band-5 bursts but revealed no strictly simultaneous counterparts to the corresponding Band-4 bursts. These results suggest frequency-dependent burst occurrence and are consistent with patchy spectral occupancy over the 550--1460 MHz frequency range. The detected bursts exhibit diverse temporal and spectral morphologies. Consecutive bursts were observed with separations of 16.7(2)-291.5(6) ms, revealing short repetition intervals and possible sub-second quasi-periodicity. The waiting-time and energy distributions are bimodal, indicating at least two characteristic emission timescales and energy modes. Burst fluences span 1.7(3)-78(3) Jy ms, and the cumulative fluence distribution is well described by a broken power law. These results provide a simultaneous multi-frequency view of FRB 20201124A during its May 2021 active episode and support a picture in which the source exhibits complex frequency-dependent activity and broadband emission behaviour.

[abstract 20 / 37] (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: 13 pages, 7 figures

Subjects: physics.plasm-ph

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

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 21 / 37] (score: 2)
arXiv:2607.08290 [pdf, ps, other]

Title: Sensitivity of a low-shear heliotron configuration to localised ferrite-steel perturbations

Authors: A. Matsuyama, F. Tanji, Y. Nakamura, S. Inagaki, Yusuke Yamashita, Akihisa Yamamoto, S. Kobayashi, F. Kin, S. Kado, S. I. Inagaki, S. Konoshima, T. Mizuuchi, K. Nagasaki,

Comments: 21 pages, 14 figures

Subjects: physics.plasm-ph

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

The influence of ferritic steel on low-shear stellarator/heliotron MAGNETic configurations is investigated for the Heliotron J device using a point dipole MAGNETisation model. By numerically evaluating ferritic steel plates assumed at several locations inside the Heliotron J vacuum vessel, the changes in the rotational transform and MAGNETic island width are shown to be sensitive to the installation location. This location sensitivity arises from the toroidal variation of poloidal mode coupling between the background nonaxisymmetric field and ferritic-steel perturbation, rather than being determined solely by the perturbation amplitude. The resulting mode coupling can enhance the resonant vacuum MAGNETic perturbation at specific locations. Ferritic steel plates placed on the outer side of a straight section produce the most significant changes in the MAGNETic topology and exhibit the highest sensitivity to violations of the $M=4$ toroidal periodicity. Additionally, we show that appropriate arrangements of passive MAGNETic dipoles can reduce the effective helical ripple while preserving the vacuum MAGNETic well depth in Heliotron J, and can induce a stellarator-asymmetric boundary perturbation in low-field experiments.

[abstract 22 / 37] (score: 2)
arXiv:2607.29362 [pdf, ps, other]

Title: Nonlinear POLARIZATION effects on plasma screening for fusion reactions

Authors: Hanxiang Huang, Binbing Wu, Zhengfeng Fan, Congzhang Gao, Jie Liu, Baisong Xie,

Comments:

Subjects: physics.plasm-ph nucl-th

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Using a finite-temperature two-center Thomas-FERMI-Dirac model, we investigate nonlinear plasma screening effects on the fusion reactions D-T, $^{12}$C-$^{12}$C, and p-$^{11}$B. The effective interaction between a reacting ion pair is obtained self-consistently at the mean-field level. Combining this potential with a complex Woods-Saxon nuclear potential, we solve the stationary Schrödinger equation to evaluate tunneling probabilities and reaction rates. Compared with Debye-Hückel theory, the two-center screening potential can be stronger or weaker, and the resulting fusion enhancement correspondingly amplified or suppressed, depending on the plasma conditions and the internuclear separation. We identify the underlying mechanisms: relative to the single-center prediction, the nonlinear evacuation of background ions suppresses screening, whereas nonlinear electron accumulation enhances it. The two channels respond to different plasma state parameters: the ionic suppression deepens with increasing coupling strength, whereas the electronic enhancement peaks at intermediate degeneracy. The two-center correction therefore follows a factorized scaling law in the nuclear charges of the reacting pair and the plasma state parameters. These findings highlight the importance of a self-consistent two-center treatment for determining effective interactions and evaluating static screening corrections to fusion reaction rates.

[abstract 23 / 37] (score: 2)
arXiv:2609.01590 [pdf, ps, other]

Title: TeV Higgsino Dark Matter from LZ Nuclear Recoil to FERMI-LAT Gamma Rays

Authors: Lei Wu, Yang Zhang, Bin Zhu,

Comments: Updated version, two columns, 7+8 pages. Added numerical calculations of non-equilibrium annihilation of solar-captured dark matter and the LMC-enhanced high-velocity tail

Subjects: hep-ph

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

The excess of high-energy nuclear recoils, which was recently reported by the LUX-ZEPLIN (LZ) experiment, together with the FERMI-LAT Galactic-Center preference, suggests new physics beyond the standard model (SM). One of the minimal extensions of the SM is to introduce a fermionic electroweak doublet in which the lightest neutral component can play the role of a stable DARK MATTER particle. We show that the minimal higgsino DARK MATTER can offer a common origin for both excesses. The inferred mass splitting, however, depends on the local DARK MATTER velocity distribution, and including the high-velocity tail generated by the gravitational influence of the Large Magellanic Cloud yields $δ_m =481$--$519~\mathrm{keV}$ for $m_χ=1000$--$1183~\mathrm{GeV}$ at $1σ$ level. Near elastic-scattering blind spots, solar-captured higgsinos fail to reach thermal equilibrium, weakening their annihilation signal, so that ten years of IceCube data exclude $δ_m \lesssim 475~\mathrm{keV}$ at 90% C.L. The viable parameter space can be tested through the associated gamma-ray line, which is within the projected reach of CTAO.

[abstract 24 / 37] (score: 2)
arXiv:2609.17680 [pdf, ps, other]

Title: A dense, metal-rich absorber driven by a heavily dust-obscured galaxy: The direct evidence of CGM enrichment at $z\sim7$

Authors: Qinyue Fei, Seiji Fujimoto, Gabriel Brammer, Lise Christensen, Marianne Vestergaard, Rohan P. Naidu, Robert A. Simcoe, Norman Murray, Luis C. Ho, Ruancun Li, Volker Bromm, Javier Álvarez-Márquez, Hollis B. Akins, Yoshihisa Asada, Simona Di Stefano, Kohei Inayoshi, Vasily Kokorev, Jorryt Matthee, Romain A. Meyer, Ava Polzin, Francesco Valentino, Fabian Walter, Marcel Neeleman, Yunjing Wu, Mengyuan Xiao,

Comments: Submitted to ApJ. Comments and questions are welcome!

Subjects: astro-ph.GA

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

We report the serendipitous discovery of a dense, metal-enriched circumgalactic medium (CGM) absorber at z=7.03, together with its host galaxy, identified along the sightline toward a red QUASAR. The absorber exhibits the largest rest-frame equivalent widths and column densities observed to date at z>5, tracing a metal-enriched gaseous halo. Using deep JWST/NIRSpec and NOEMA observations, we characterize the absorber's physical properties and identify its host, ND1, as a vigorously star-forming galaxy at an exceptionally close impact parameter of ~16kpc, so heavily dust-obscured that it is detected only in the longest-wavelength NIRCam bands. Detections of [OIII]$λ$5007, H$α$, and [CII]$λ158\,μ$m emission anchor the systemic redshift to z~7.0321, revealing a coherent ~50km/s blueshift of the absorbing gas relative to the host, suggesting outflow-driven metal transport into the halo. The outflow velocity, combined with the measured column density, implies an outflow rate of $\dot{M}_{\rm out}=64 M_\odot\,yr^{-1}$ and a mass loading factor $η=3$, indicating an energetic, chemically-enriched wind launched from a dust-obscured starburst. While the overall ionization state and [Mg/Fe] ratio align with empirical cosmic evolutionary trends, the absorber displays an enhanced carbon-to-oxygen ([C/O]) ratio. This abundance pattern suggests the nucleosynthetic yields of Population~III stellar explosions, and aligns with the host's star-formation history extending to $z \gtrsim 8$, potentially offering a rare fossil record of primordial metal enrichment. Our findings demonstrate that intense star-formation feedback can rapidly and efficiently pollute the CGM/IGM well into the Epoch of Reionization. The NIR-dark nature of the host further implies that rest-UV surveys may systematically miss the dusty sources that drive CGM- and IGM-scale metal enrichment in the early Universe.

[abstract 25 / 37] (score: 2)
arXiv:2609.19175 [pdf, ps, other]

Title: An Operative Viability Boundary for Relaxed Single-Particle Penrose Extraction in Kerr-Vaidya Spacetimes

Authors: Fabio Buffoli,

Comments: 20 pages, 6 figures, 6 tables

Subjects: gr-qc astro-ph.HE

Created: 2026-09-15; Updated: 2026-09-18; Datestamp: 2026-09-18

We present a corrected numerical investigation of the Penrose process in the Kerr-Vaidya metric for a rotating BLACK HOLE losing mass at constant rate. We fix two errors from an earlier version: an incorrect metric component g_r phi (verified by transformation from Boyer-Lindquist coordinates) and the omission of the Wald/Christodoulou area theorem in the split optimization. Using the standard single-particle treatment (energy and angular momentum conserved at the split, but not the escaping fragment's radial momentum), we compute optimal trajectories and the bounded energy gain Delta E = E3 - E1 versus spin a/M and mass-loss rate alpha. For static Kerr holes, Delta E rises with spin from about 0.106 M at a/M = 0.8 to 0.245 M at a/M = 0.99. In the dynamic case, holding a fixed while m(v) decreases causes the effective spin a/m(v) to drift strongly toward extremality (from 0.81 to 0.9999), a geometric effect that makes static-dynamic comparisons at equal nominal a/M misleading. We map the critical mass-loss rate alpha_crit(a) above which no viable extraction is found (using m >= 0), obtaining alpha_crit(0.90) ~ 0.036, alpha_crit(0.95) ~ 0.019 and alpha_crit(0.99) ~ 0.0038, decreasing with spin. A check with full four-momentum conservation recovers the Bardeen-Press-Teukolsky bound near the horizon, but escaping solutions are rare away from it; thus our main results refer to the relaxed single-particle formulation common in the literature.

[abstract 26 / 37] (score: 2)
arXiv:2609.19187 [pdf, ps, other]

Title: Effects of radial conductivity variation on the Ponomarenko dynamo

Authors: Shipra Verma, Kannabiran Seshasayanan,

Comments: 11 pages, 8 figures. Published in Phys. Rev. E

Subjects: astro-ph.SR physics.flu-dyn physics.plasm-ph

Created: 2026-09-15; Updated: 2026-09-18; Datestamp: 2026-09-18

We study the effects of conductivity variation on the Ponomarenko dynamo. Taking monotonically increasing/decreasing and sinusoidally varying radial profiles, we study the kinematic dynamo problem. The threshold of the dynamo, given by the critical MAGNETic Reynolds number Rm$_c$, is found to strongly depend on the form of conductivity variation near the discontinuity of the velocity field where the shear is dominant. For monotonically varying profiles in the limit of sharp variation, this threshold maps to the problem of the dynamo with a jump in conductivity, while for the sinusoidal profile with large variations/wavenumbers, the threshold increases due to effective diffusivity arising from the rapid changes in conductivity. Far from the threshold, it is found that the growth rate depends only on the local gradient of the conductivity near the discontinuity, with the opposite sign of shear and conductivity gradient leading to a larger growth rate, thereby aiding the dynamo instability in regenerating B$_ϕ$ from B$_r$. We calculate the expression for the growth rate in the limit of large Rm$(\gg 1)$ and find that the conductivity variation leads to a modification proportional to the local gradient of conductivity times Rm$^{-1/2}$. This correction is found to depend only on the local gradient of the conductivity at the discontinuity. Similar dependencies are found for realistic, smooth velocity profiles and for different MAGNETic boundary conditions.

[abstract 27 / 37] (score: 2)
arXiv:2609.19284 [pdf, ps, other]

Title: Lukewarm inflation and the QCD axion

Authors: Paulo B. Ferraz, António Torres Manso, João G. Rosa,

Comments: 12 pages, 5 figures

Subjects: hep-ph astro-ph.CO

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

We show that a late period of warm inflation, at temperatures just above the QCD scale, can dilute the abundance of the QCD axion produced by the misalignment mechanism, thus avoiding the need to fine-tune the initial misalignment angle in scenarios with an axion decay constant close to the GUT scale. We develop a concrete realization of this lukewarm inflation stage involving right-handed neutrinos in 0.1 - 1 GeV mass range and an associated scalar sector, showing that coherent axion oscillations are damped during this period. In this scenario, a previously generated large baryon asymmetry may also be diluted to yield the observed value, and lukewarm inflation is followed by an early-matter era dominated by the lightest right-handed neutrino, before it decays into Standard Model states. This model can be tested via changes to the number of RELATIVISTIC species and the induced small-scale enhancements of the primordial curvature power spectrum, leading to primordial BLACK HOLEs and scalar-induced gravitational waves.

[abstract 28 / 37] (score: 2)
arXiv:2609.19462 [pdf, ps, other]

Title: On Stochastic Memory Backgrounds In LISA

Authors: James Buda, Andrew Laeuger, Yanbei Chen,

Comments: 14 pages, 10 figures, submitted to Physical Review D

Subjects: gr-qc

Created: 2026-09-16; Updated: 2026-09-18; Datestamp: 2026-09-18

Gravitational-wave (GW) memory is a permanent change in spacetime geometry induced by a burst of gravitational waves. It is theoretically interesting for its connection to asymptotic symmetries, but has not yet been observed. The upcoming Laser Interferometer Space Antenna (LISA) is predicted to detect memory directly in loud events from supermassive BLACK HOLE (SMBH) mergers. We assess the prospects for the cumulative effect of memory contributions as a stochastic GW memory background (SGWMB). Using two SMBH population models, we recover previously obtained single-event SNR forecasts and compute the power spectrum of the unresolved background, using numerical-relativity waveforms for modeling the memory signal during each event. We find the predicted spectrum is significantly smaller than ones found by modeling the memory waveform with a Heaviside function, with expected SNRs of order $O(0.1-10)$. We further find that our models favor a highly non-Gaussian ("popcorn") spectrum, demonstrating that the background may not appear as the union of continuous, overlapping signals, but rather as a collection of intermittent bursts. In both measures, we demonstrate that any current prediction of the spectrum is heavily dependent on the choice of population model. We interpret these findings in the light of the future LISA mission and emphasize their importance for properly handling memory within the LISA global fit.

[abstract 29 / 37] (score: 2)
arXiv:2609.19667 [pdf, ps, other]

Title: Experimental study of the impact dynamics of polymeric hollow droplets

Authors: Mohammad Mahdi Nasiri, Mohammad Reza Daneshvar Garmroodi, Damian Vadillo, Moussa Tembely,

Comments: Submitted to Physics of Fluids

Subjects: physics.flu-dyn

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

The impact dynamics of hollow droplets, while influential in applications such as coating and spraying, remain less explored than their dense counterparts. In particular, the impact dynamics of viscoelastic hollow droplets have yet to be fully explored. This study presents an experimental investigation into the impact of hollow Newtonian (water) and viscoelastic (polymeric solution) droplets on a solid surface at different impact velocities and polymer concentrations. We demonstrate two hallmark features of hollow droplet flattening: the formation of a central counter-JET and the final deposition, both associated with the entrapped air bubble. For Newtonian droplets, the counter-JET exhibits rapid growth and breakup due to capillary instabilities. Introducing polymer additives fundamentally alters this behavior: viscoelasticity affects the counter-JET's height and velocity, delays bubble rupture, and inhibits droplet detachment. Crucially, we observe the emergence of beads-on-a-string structures during filament thinning, a signature of the competition between elastic and capillary forces. By systematically varying the polymer concentration and impact velocity, we identify the conditions under which three distinct outcomes occur: deposition, partial deposition, and detachment. Our results show how inertia, viscosity, capillarity, and elasticity together govern the splashing morphology of hollow non-Newtonian droplets.

[abstract 30 / 37] (score: 2)
arXiv:2609.19788 [pdf, ps, other]

Title: Widespread plasma JETs in the Martian MAGNETosheath revealed by dual-spacecraft observations

Authors: Abigail Tadlock, Chuanfei Dong, Chi Zhang, Savvas Raptis, Hongyang Zhou, Xinmin Li, Jiawei Gao,

Comments:

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

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Plasma JETs in planetary MAGNETosheaths are transient, high dynamic pressure structures capable of strongly perturbing downstream MAGNETospheres and modulating solar wind energy transfer. Although recently identified at Mars, their formation mechanisms and global occurrence remain poorly constrained. Using dual-spacecraft observations from Mars Atmosphere and Volatile EvolutioN (MAVEN) and Tianwen-1, we show that MAGNETosheath JETs occur throughout the Martian MAGNETosheath, in striking contrast to Earth where JET occurrence is strongly controlled by interplanetary MAGNETic field orientation and largely confined to quasi-parallel shock regions. We propose that this widespread distribution is linked to Mars' extended hydrogen corona, which generates pickup ions that drive proton-cyclotron waves upstream of the bow shock. Because this mechanism is generic to any body with an extended corona (or exosphere) embedded in a stellar wind, this finding bears on solar-wind interactions at comets and other small bodies, and on the space environments of unMAGNETized terrestrial exoplanets. These results indicate that MAGNETosheath JET formation can be governed not only by external solar wind forcing but also by intrinsic planetary properties, pointing to a previously unrecognized pathway for solar wind-planet coupling at unMAGNETized worlds.

[abstract 31 / 37] (score: 2)
arXiv:2609.19950 [pdf, ps, other]

Title: Meerkat measurement of the radio emission from massive stars in the Galactic plane I. Wolf-Rayet stars

Authors: Mathilde Tasseroul, Michaël De Becker, Paula Benaglia, Anandmayee Tej,

Comments: The full version of Table 1 is available at the CDS via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/713/A154

Subjects: astro-ph.SR

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Massive stars, including Wolf-Rayet stars, are predominantly found in binary systems. These systems are known to emit both thermal emission from stellar winds and, occasionally, non-thermal emission produced by RELATIVISTIC electrons accelerated in the wind-wind interaction region. We intend to provide the most complete census of radio emission from WR stars in the Galactic plane, using the SARAO MeerKAT Galactic Plane Survey (SMGPS) complemented by the MeerKAT Galactic Center Survey. Our main motivation is to identify hints of SYNCHROTRON radio emission indicative of particle-accelerating colliding-wind binaries (PACWBs). We compiled an input catalogue of 428 WR stars positionally covered by the SMGPS and the MGCS. Using the survey data, we measured the radio emission at 1.3 GHz for detected WR stars. We also measured the upper limits for objects located in sufficiently low radio background regions. For detected objects, we searched for a radio excess by comparing the measured fluxes to two different evaluators of the thermal emission from massive star winds. We detected 23 targets and determined the upper limits for 279 WR stars. Among the detected objects, 15 display a (significant or potential) radio excess that cannot be explained by unresolved circumstellar emission of any kind. After removing already known PACWBs, we report the identification of 12 potential new PACWB candidates. Our study has led to the compilation of the most extensive catalogue of Galactic WR radio emission to date, based on a homogeneous dataset covering the Galactic plane. The low detection rate indicates either a low occurrence rate of SYNCHROTRON emission or substantial attenuation by turnover processes that are clearly dominated by free-free absorption from the WR wind material. Our results open the door to dedicated follow-up observations aimed at ascertaining the nature of the identified radio excesses.

[abstract 32 / 37] (score: 2)
arXiv:2609.19953 [pdf, ps, other]

Title: Gradient-Based Construction of Collisionless Steady-State Guiding-Center Distributions in Tokamaks and Stellarators

Authors: Jingyi Yu, Chang Liu,

Comments: 23 pages, 6 figures

Subjects: physics.plasm-ph

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

We present a matrix-free residual-minimization method for preparing guiding-center distribution functions on finite grids. The method minimizes a fixed conservative discrete residual in the physical Jacobian metric using Polak-Ribiere+ iterations with exact quadratic line searches. JAX/XLA evaluates the operator and its adjoint without assembling a four-dimensional matrix; independent MAGNETic-moment slices are batched and iterations are compiled into one execution graph. An axisymmetric hierarchy verifies invariant references and tests the workflow using a NUBEAM fast-ion distribution together with an EPCoM constants-of-motion representation constructed from it, before matched precise quasi-axisymmetric (precise-QA), HSX, and W7-X calculations. The three-dimensional endpoints reduce the discrete residual and the finite-time variation of the distribution sampled along independently integrated characteristics. Non-negative projection is treated as an optional constrained extension: it leaves the residual operator unchanged but changes the feasible zero-residual set and endpoint selection. Results are finite-grid, finite-time evidence and do not establish a continuous equilibrium, grid convergence, strict positivity, or a transport prediction.

[abstract 33 / 37] (score: 2)
arXiv:2609.19980 [pdf, ps, other]

Title: Polarization Observations of a sample of Excited OH masers

Authors: Derck P. Smits, Paul Fallon,

Comments: 29 pages, 20 figures, 6 tables

Subjects: astro-ph.GA

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Spectra of 4.7 and 6.0 GHz excited OH masers from 21 pointings towards known star-forming regions are reported. The C-band observations, using the Green Bank Telescope in full Stokes mode, have measured how POLARIZATION properties vary across the maser profiles in each spectrum and vary between different epochs of observation. Seven sources had no detections of masers at any of the OH transitions. Nine sources were observed to have 4.766 GHz masers, which include two new detections in G188.946+0.886 and G196.454-1.677. No new linear or circular POLARIZATION was found in any of these masers. Seven and two sources had 6.035 and 6.031 GHz masers, respectively. All 6.035 GHz masers had some level of circular POLARIZATION, and three also had linear POLARIZATION. Both linear and circular POLARIZATION were found in the 6.031 GHz masers in G133.947+1.064, and weak, 100% LCP in G141.918+1.902. Magnetic fields have been calculated from measured Zeeman splittings. The strength and orientation of the fields agree with most previous measurements, although there are some indications that the MAGNETic fields could be changing. Thermal emission or absorption is seen in several of the 4.7 and 6.0 GHz transitions, many of which have not been reported before.

[abstract 34 / 37] (score: 2)
arXiv:2609.20102 [pdf, ps, other]

Title: The SHARPEx space-to-space VLBI experiment

Authors: Freek Roelofs, Christiaan Brinkerink, Albert Catalan Artigas, Heino Falcke, Jaime Fernández, Christian M. Fromm, Felix Glaser, Marc Klein Wolt, Yuri Kovalev, Volodymyr Kudriashov, María Manzano, Rasmus Maråk, Manuel Martin-Neira, Jacobo Pastor Fernández-Posse López, Montserrat Puertolas Turell, Alberto Rodríguez Pérez-Silva, René Rüddenklau, Efthalia Traianou, Roger Vilaseca Miro,

Comments: 16 pages, 5 figures. Presented at SPIE Astronomical Telescopes + Instrumentation 2026, "Radio Telescopes, Technologies, and Methods" (Proc. SPIE Vol. 14153, paper 1415319), Copenhagen, Denmark, 5-10 July 2026

Subjects: astro-ph.IM

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Space is the next frontier for ultra-high resolution imaging of astrophysical sources with very long baseline interferometry (VLBI). The limited size of the Earth and atmospheric absorption and turbulence at high frequencies prevent order-of-magnitude resolution improvements from current BLACK HOLE imaging with the ground-based Event Horizon Telescope. A two or three-element submm space-based array like SHARP would image the thin BLACK HOLE photon ring and measure the BLACK HOLE spin and spacetime. Here, we present the SHARP Experiment (SHARPEx) mission concept. SHARPEx will demonstrate key enabling technologies for space-to-space VLBI, including clock syntonization between two satellites, on-board correlation, and sub-wavelength relative orbit determination. SHARPEx will consist of two CubeSat or SmallSat platforms carrying small (~1 m diameter) antennas, observing at cm wavelengths. While SHARPEx will be a technical demonstrator, a SHARPEx-type follow-up mission with enhanced intersatellite link properties (range and bandwidth) may produce images of bright AGN with unprecedented resolution and fidelity.

[abstract 35 / 37] (score: 2)
arXiv:2609.20136 [pdf, ps, other]

Title: Reconstruction of Beam Transverse Parameters in the FERMIlab Side-Coupled Linac Using a Normalized Coordinate Framework

Authors: E. V. Chen, J-P. Carneiro, R. V. Sharankova, A. V. Shemyakin,

Comments: 33rd Linear Accelerator Conference (LINAC 2026)

Subjects: physics.acc-ph

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

Quadrupole scans are a commonly used tool for beam second moment reconstruction. Limitations in the strength of the MAGNETs and layout of the beamline elements frequently preclude simple quadrupole-drift-detector scans from collecting sufficient data for reconstruction. Using a normalized coordinate framework, we characterize the prerequisites for a robust simple quadrupole scan and expand these prerequisites to reconstruction from more complex optics. The beam second moments are investigated at two locations in the FERMIlab Side-Coupled Linac under simple and complex optics, using this framework to maximize information gained from wire scanner profile measurements.

[abstract 36 / 37] (score: 2)
arXiv:2609.20338 [pdf, ps, other]

Title: Evolution and mergers of eccentric white dwarf binaries encountering intermediate-mass BLACK HOLEs

Authors: Adarsh Pandey, Aryabrat Mahapatra, Tapobrata Sarkar,

Comments: 16 pages + 5 pages of appendix, 19 figures

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

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

We study how a close passage past an intermediate-mass BLACK HOLE (IMBH) changes the evolution of an eccentric white dwarf (WD) binary that has nominal Roche lobe overflow at internal pericenter. Using three-dimensional smoothed particle hydrodynamics, we follow binaries with eccentricity $e_{\rm in}=0.6$ and mass ratios $q=0.2$ -- $0.7$ on parabolic, retrograde orbits around a Schwarzschild IMBH at two encounter strengths, $β^b=0.5$ and $1.5$. We compare them with the same binaries evolved in isolation. The IMBH greatly speeds up the merger. Every IMBH-perturbed binary that merges does so during or shortly after its second internal pericenter passage, which is always less than the time taken to merge in isolation. The merger outcome is not monotonic with encounter strength. The $q=0.2$ binary retains two bound cores for $β^b=1.5$ but merges at $β^b=0.5$. In the deeper encounter it settles onto a less eccentric post-encounter orbit, showing that the timing of the encounter relative to the inner orbit plays an important role. Deep encounters also produce transient reversals of the internal orbital angular momentum for $q=0.2$ -- $0.4$, while the material bound to the accretor gains more spin angular momentum than that bound to the donor. The specific orbital angular momentum of the binary CM around the IMBH changes by only a few $\times10^{-4}$ of its initial value. We also identify He-origin material that can burn helium on a dynamical timescale, amounting to $\sim15$ -- $17\%$ of the He-origin mass for $q=0.7$. IMBH encounters can therefore quantitatively change the evolution of eccentric WD binaries.

[abstract 37 / 37] (score: 2)
arXiv:2609.20745 [pdf, ps, other]

Title: Low Frequency Radio Imaging Study of PSR J1818-1607

Authors: A. Yadav, M. P. Surnis, B. C. Joshi, M. Bagchi,

Comments:

Subjects: astro-ph.HE

Created: 2026-09-17; Updated: 2026-09-18; Datestamp: 2026-09-18

We report on the low-frequency radio observations of MAGNETar PSR J1818$-$1607 carried out with the upgraded Giant Metrewave Radio Telescope at band 3 (300$-$500 MHz) and band 4 (550-750 MHz). We have identified the continuum source associated with the MAGNETar and report variations in flux density and its spectral index. The flux density timeseries for the MAGNETar reveals the presence of two potential radio flaring episodes with varying spectral properties. We discuss the implications of the spectral index changes on the potential emission mechanisms for radio-loud MAGNETars. We also report non-detections of the continuum source as well as no direct indication for an associated diffuse emission from multiple archival radio imaging surveys.