The prompt to late-time multiwavelength analysis of GRB 060210

¹ Astronomical Institute, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands e-mail: pcurran@science.uva.nl
² Department of Physics & Astronomy, University of Leicester, LE1 7RH, UK
³ Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Birkenhead, CH41 1LD, UK
⁴ Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
⁵ Present Address: INAF – Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate (LC), Italy
⁶ NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
⁷ Present Address: Institut Néel, CNRS, 25 avenue des Martyrs, 38000 Genoble, France

Received: 4 January 2007
Accepted: 12 March 2007

Abstract

Aims.We present our analysis of the multiwavelength photometric & spectroscopic observations of GRB 060210 and discuss the results in the overall context of current GRB models.

Methods.All available optical data underwent a simultaneous temporal fit, while X-ray and γ-ray observations were analysed temporally & spectrally. The results were compared to each other and to possible GRB models.

Results.The X-ray afterglow is best described by a smoothly broken power-law with a break at 7.4 h. The late optical afterglow has a well constrained single power-law index which has a value between the two X-ray indices, though it does agree with a single power-law fit to the X-ray. An evolution of the hardness of the high-energy emission is demonstrated and we imply a minimum host extinction from a comparison of the extrapolated X-ray flux to that measured in the optical.

Conclusions.We find that the flaring γ-ray and X-ray emission is likely due to internal shocks while the flat optical light curve at that time is due to the external shock. The late afterglow is best explained by a cooling break between the optical and X-rays and continued central engine activity up to the time of the break. The required collimation corrected energy of ~210⁵² erg, while at the high end of the known energy distribution, is not unprecedented.