Continuous optical monitoring during the prompt emission of GRB 060111B

Alain Klotz (1, 2) , Bruce Gendre (3) , Giulia Stratta (2, 4) , Jean-Luc Atteia (4) , Michel Boer (2) , Frederic Malacrino (4) , Yassine Damerdji (1, 2) , Raoul Behrend (5)

1 CESR - Centre d'étude spatiale des rayonnements
2 OHP - Observatoire de Haute-Provence
3 IASF, Roma
4 LATT - Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées
5 ObsGE - Observatoire Astronomique de l'Université de Genève

We present the time-resolved optical emission of GRB 060111B during its prompt phase, measured with the TAROT robotic observatory. This is the first time that the optical emission from a gamma-ray burst has been continuously monitored with a temporal resolution of a few seconds during the prompt gamma-ray phase. The temporal evolution of the prompt optical emission at the level of several seconds is used to provide a clue to the origin of this emission. The optical emission was found to decay steadily from our first measure, 28s after the trigger, in contrast to the gamma-ray emission, which exhibits strong variability at the same time. This behaviour strongly suggests that the optical emission is due to the reverse shock.

Mots clés: Gamma-ray burst

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]

Alain Klotz, Bruce Gendre, Giulia Stratta, Jean-Luc Atteia, Michel Boer, et al.. Continuous optical monitoring during the prompt emission of GRB 060111B. 2006. ⟨hal-00022114⟩