Details

Autor(en) / Beteiligte

• Greiner, J.
• Yu, H.-F.
• Krühler, T.
• Frederiks, D. D.
• Beloborodov, A.
• Bhat, P. N.
• Bolmer, J.
• van Eerten, H.
• Aptekar, R. L.
• Elliott, J.
• Golenetskii, S. V.
• Graham, J. F.
• Hurley, K.
• Kann, D. A.
• Klose, S.
• Nicuesa Guelbenzu, A.
• Rau, A.
• Schady, P.
• Schmidl, S.
• Sudilovsky, V.
• Svinkin, D. S.
• Tanga, M.
• Ulanov, M. V.
• Varela, K.
• von Kienlin, A.
• Zhang, X.-L.

Titel

GROND coverage of the main peak of gamma-ray burst 130925A

Ist Teil von

• Astronomy and astrophysics (Berlin), 2014-08, Vol.568, p.A75

Ort / Verlag

EDP Sciences

Erscheinungsjahr

2014

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Aims. Prompt or early optical emission in gamma-ray bursts (GRBs) is notoriously difficult to measure, and observations of the dozen cases show a large variety of properties. Yet, such early emission promises to help us achieve a better understanding of the GRB emission process(es). Methods. We performed dedicated observations of the ultra-long duration (T90 about 7000 s) Swift GRB 130925A in the optical/near-infrared with the 7-channel Gamma-Ray burst Optical and Near-infrared Detector (GROND) at the 2.2 m MPG/ESO telescope. Results. We detect an optical/near-infrared flare with an amplitude of nearly 2 mag which is delayed with respect to the keV−MeV prompt emission by about 300−400 s. The decay time of this flare is shorter than the duration of the flare (500 s) or its delay. Conclusions. While we cannot offer a straightforward explanation, we discuss the implications of the flare properties and suggest ways toward understanding it.