Gamma-ray astronomy

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Type I X-ray Bursts Reflected During the X-ray Eclipses of EXO 0748-676

(2025)

Authors:

Amy H Knight, Jakob van den Eijnden, Adam Ingram, James H Matthews, Sara E Motta, Matthew Middleton, Giulio C Mancuso, Douglas JK Buisson, Diego Altamirano, Rob Fender, Timothy P Roberts
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The observed phase space of mass-loss history from massive stars based on radio observations of a large supernova sample

(2025)

Authors:

Itai Sfaradi, Assaf Horesh, Rob Fender, Lauren Rhodes, Joe Bright, David Williams-Baldwin, Dave A Green
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Detection of very-high-energy gamma-ray emission from Eta Carinae during its 2020 periastron passage

(2025)

Authors:

HESS Collaboration, F Aharonian, F Ait Benkhali, J Aschersleben, H Ashkar, V Barbosa Martins, R Batzofin, Y Becherini, D Berge, K Bernlöhr, M Böttcher, C Boisson, J Bolmont, M de Bony de Lavergne, F Bradascio, R Brose, A Brown, F Brun, B Bruno, C Burger-Scheidlin, S Casanova, J Celic, M Cerruti, T Chand, S Chandra, A Chen, J Chibueze, O Chibueze, T Collins, G Cotter, J Damascene Mbarubucyeye, J de Assis Scarpin, J Devin, A Djannati-Ataï, J Djuvsland, A Dmytriiev, K Egberts, S Einecke, J-P Ernenwein, C Escañuela Nieves, K Feijen, M Filipovic, G Fontaine, S Funk, S Gabici, JF Glicenstein, G Grolleron, M-H Grondin, L Haerer, B Heß, JA Hinton, W Hofmann, TL Holch, M Holler, D Horns, Zhiqiu Huang, M Jamrozy, F Jankowsky, A Jardin-Blicq, I Jung-Richardt, K Katarzyński, R Khatoon, B Khélifi, W Kluźniak, Nu Komin, K Kosack, D Kostunin, RG Lang, S Le Stum, A Lemière, M Lemoine-Goumard, J-P Lenain, A Luashvili, J Mackey, D Malyshev, V Marandon, A Marcowith, G Martí-Devesa, R Marx, A Mehta, A Mitchell, R Moderski, MO Moghadam, L Mohrmann, E Moulin, M de Naurois, J Niemiec, S Ohm, L Olivera-Nieto, E de Ona Wilhelmi, M Ostrowski, S Panny, M Panter, RD Parsons, U Pensec, G Pühlhofer, A Quirrenbach, S Ravikularaman, M Regeard, A Reimer, O Reimer, Q Remy, H Ren, B Reville, F Rieger, G Rowell, B Rudak, E Ruiz-Velasco, K Sabri, V Sahakian, H Salzmann, A Santangelo, M Sasaki, J Schäfer, F Schüssler, HM Schutte, JNS Shapopi, S Spencer, Ł Stawarz, R Steenkamp, S Steinmassl, C Steppa, K Streil, T Tanaka, R Terrier, M Tluczykont, M Tsirou, N Tsuji, C van Eldik, M Vecchi, C Venter, T Wach, SJ Wagner, F Werner, R White, A Wierzcholska, M Zacharias, AA Zdziarski, A Zech, N Żywucka
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State-dependent signatures of jets and winds in the optical and infrared spectrum of the black hole transient GX 339$-$4

(2025)

Authors:

A Ambrifi, D Mata Sánchez, T Muñoz-Darias, J Sánchez-Sierras, M Armas Padilla, MC Baglio, J Casares, JM Corral-Santana, VA Cúneo, RP Fender, G Ponti, DM Russell, M Shidatsu, D Steeghs, MAP Torres, Y Ueda, F Vincentelli

Late-time Radio Brightening and Emergence of a Radio Jet in the Changing-look AGN 1ES 1927+654

The Astrophysical Journal Letters American Astronomical Society 979:1 (2025) L2

Authors:

Eileen T Meyer, Sibasish Laha, Onic I Shuvo, Agniva Roychowdhury, David A Green, Lauren Rhodes, Amelia M Hankla, Alexander Philippov, Rostom Mbarek, Ari laor, Mitchell C Begelman, Dev R Sadaula, Ritesh Ghosh, Gabriele Bruni, Francesca Panessa, Matteo Guainazzi, Ehud Behar, Megan Masterson, Haocheng Zhang, Xiaolong Yang, Mark A Gurwell, Garrett K Keating, David Williams-Baldwin, Justin D Bray

Abstract:

We present multifrequency (5–345 GHz) and multiresolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic nuclei (CL-AGNs). The source was first designated a CL-AGN after an optical outburst in late 2017 and has since displayed considerable changes in X-ray emission, including the destruction and rebuilding of the X-ray corona in 2019–2020. Radio observations prior to 2023 show a faint and compact radio source typical of a radio-quiet AGN. Starting in 2023 February, 1ES 1927+654 began exhibiting a radio flare with a steep exponential rise, reaching a peak 60 times previous flux levels, and has maintained this higher level of radio emission for over a year to date. The 5–23 GHz spectrum is broadly similar to gigahertz-peaked radio sources, which are understood to be young radio jets less than ∼1000 yr old. Recent high-resolution Very Long Baseline Array observations at 23.5 GHz now show resolved extensions on either side of the core, with a separation of ∼0.15 pc, consistent with a new and mildly relativistic bipolar outflow. A steady increase in the soft X-ray band (0.3–2 keV) concurrent with the radio may be consistent with jet-driven shocked gas, though further observations are needed to test alternate scenarios. This source joins a growing number of CL-AGNs and tidal disruption events that show late-time radio activity, years after the initial outburst.
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