Gamma-ray astronomy

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Hydrogen Intensity and Real-Time Analysis Experiment: 256-element array status and overview

Journal of Astronomical Telescopes Instruments and Systems SPIE, the international society for optics and photonics 8:1 (2022) 011019-011019

Authors:

Devin Crichton, Moumita Aich, Adam Amara, Kevin Bandura, Bruce A Bassett, Carlos Bengaly, Pascale Berner, Shruti Bhatporia, Martin Bucher, Tzu-Ching Chang, H Cynthia Chiang, Jean-Francois Cliche, Carolyn Crichton, Romeel Dave, Dirk IL De Villiers, Matt Dobbs, Aaron M Ewall-Wice, Scott Eyono, Christopher Finlay, Sindhu Gaddam, Ken Ganga, Kevin G Gayley, Kit Gerodias, Tim B Gibbon, Austine Gumba, Neeraj Gupta, Maile Harris, Heiko Heilgendorff, Matt Hilton, Adam D Hincks, Pascal Hitz, Mona Jalilvand, Roufurd PM Julie, Zahra Kader, Joseph Kania, Dionysios Karagiannis, Aris Karastergiou, Kabelo Kesebonye, Piyanat Kittiwisit, Jean-Paul Kneib, Kenda Knowles, Emily R Kuhn, Martin Kunz, Roy Maartens, Vincent MacKay, Stuart MacPherson, Christian Monstein, Kavilan Moodley, V Mugundhan, Warren Naidoo, Arun Naidu, Laura B Newburgh, Viraj Nistane, Amanda Di Nitto, Deniz Ölçek, Xinyu Pan, Sourabh Paul, Jeffrey B Peterson, Elizabeth Pieters, Carla Pieterse, Aritha Pillay, Anna R Polish, Liantsoa Randrianjanahary, Alexandre Refregier, Andre Renard, Edwin Retana-Montenegro, Ian H Rout, Cyndie Russeeawon, Alireza Vafaei Sadr, Benjamin RB Saliwanchik, Ajith Sampath, Pranav Sanghavi, Mario G Santos, Onkabetse Sengate, J Richard Shaw, Jonathan L Sievers, Oleg M Smirnov, Kendrick M Smith, Ulrich Armel Mbou Sob, Raghunathan Srianand, Pieter Stronkhorst, Dhaneshwar D Sunder, Simon Tartakovsky, Russ Taylor, Peter Timbie, Emma E Tolley, Junaid Townsend, Will Tyndall, Cornelius Ungerer, Jacques van Dyk, Gary van Vuuren, Keith Vanderlinde, Thierry Viant, Anthony Walters, Jingying Wang, Amanda Weltman, Patrick Woudt, Dallas Wulf, Anatoly Zavyalov, Zheng Zhang

A MeerKAT, e-MERLIN, H.E.S.S. and Swift search for persistent and transient emission associated with three localised FRBs

(2021)

Authors:

James O Chibueze, M Caleb, L Spitler, H Ashkar, F Schussler, BW Stappers, C Venter, I Heywood, AMS Richards, DRA Williams, M Kramer, R Beswick, MC Bezuidenhout, RP Breton, LN Driessen, F Jankowski, EF Keane, M Malenta, M Mickaliger, V Morello, H Qiu, K Rajwade, S Sanidas, M Surnis, TW Scragg, CRH Walker, N Wrigley, HESS Collaboration, :, F Aharonian, F Ait Benkhali, EO Anguner, M Backes, V Baghmanyan, V Barbosa Martins, R Batzofin, Y Becherini, D Berge, M Bottcher, C Boisson, J Bolmont, M de Bony de Lavergne, M Breuhaus, R Brose, F Brun, T Bulik, F Cangemi, S Caroff, S Casanova, J Catalano, M Cerruti, T Chand, A Chen, OU Chibueze, G Cotter, P Cristofari, J Damascene Mbarubucyeye, J Devin, A Djannati Atai, A Dmytriiev, K Egberts, JP Ernenwein, A Fiasson, G Fichet de Clairfontaine, G Fontaine, S Funk, S Gabici, S Ghafourizadeh, G Giavitto, D Glawion, MH Grondin, M Horbe, C Hoischen, TL Holch, Zhiqiu Huang, M Jamrozy, F Jankowsky, I Jung Richardt, E Kasai, K Katarzynski, U Katz, B Khelifi, W Kluzniak, Nu Komin, K Kosack, D Kostunin, A Lemiere, JP Lenain, F Leuschner, T Lohse, A Luashvili, I Lypova, J Mackey, D Malyshev, V Marandon, P Marchegiani, A Marcowith, G Marti Devesa, R Marx, A Mitchell, R Moderski, L Mohrmann, E Moulin, J Muller, K Nakashima, M de Naurois, A Nayerhoda, J Niemiec, A Priyana Noel, P O'Brien, S Ohm, L Olivera Nieto, E de Ona Wilhelmi, M Ostrowski, S Panny, RD Parsons, S Pita, V Poireau, DA Prokhorov, H Prokoph, G Puhlhofer, A Quirrenbach, P Reichherzer, A Reimer, O Reimer, G Rowell, B Rudak, E Ruiz Velasco, V Sahakian, S Sailer, H Salzmann, DA Sanchez, A Santangelo, M Sasaki, HM Schutte, U Schwanke, JNS Shapopi, A Specovius, S Spencer, R Steenkamp, S Steinmassl, T Takahashi, T Tanaka, C Thorpe Morgan, N Tsuji, C van Eldik, J Veh, J Vink, SJ Wagner, A Wierzcholska, Yu Wun Wong, A Yusafzai, M Zacharias, D Zargaryan, AA Zdziarski, A Zech, SJ Zhu, S Zouari, N Zywucka

MeerKAT radio detection of the Galactic black hole candidate Swift J1842.5−1124 during its 2020 outburst

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 510:1 (2021) 1258-1263

Authors:

X Zhang, W Yu, SE Motta, R Fender, P Woudt, JCA Miller-Jones, GR Sivakoff

New constraints on light axion-like particles using Chandra transmission grating spectroscopy of the powerful cluster-hosted quasar H1821+643

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 510:1 (2021) 1264-1277

Authors:

Júlia Sisk-Reynés, James H Matthews, Christopher S Reynolds, Helen R Russell, Robyn N Smith, MC David Marsh

Observation of the gamma-ray binary HESS J0632+057 with the HESS, MAGIC, and VERITAS telescopes

Astrophysical Journal IOP Publishing 923:2 (2021) 241

Authors:

Cb Adams, W Benbow, A Brill, G Cotter, S Spencer

Abstract:

The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the Hα emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 ± 4.4 days is reported, consistent with the period of 317.3 ± 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical Hα parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.