Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/1167
Title: Early optical and millimeter observations of GRB 030226 afterglow
Authors: Pandey, S. B
Sagar, R
Anupama, G. C
Bhattacharya, D
Sahu, D. K
Castro-Tirado, A. J
Bremer, M
Keywords: gamma rays;bursts -- gamma rays
Issue Date: Apr-2004
Publisher: EDP Sciences
Citation: Astronomy and Astrophysics, Vol. 417, pp. 919-924
Abstract: The CCD magnitudes in Johnson UBV and Cousins RI photometric passbands for the afterglow of the long duration GRB 030226 are presented. Upper limits of a few mJy to millimeter wave emission at the location of optical are obtained over the first two weeks. The optical data presented here, in combination with other published data on this afterglow, show an early R band flux decay slope of 0.77 plus or minus 0.04, steepening to 2.05 plus or minus 0.04 about 0.65 + or - 0.08 day after the burst. Interpreted as the "jet break", this indicates a half opening angle of 3.2 degree for the initial ejection, for an assumed ambient density of 1cm/sup-3/ . Broadband spectra show no appreciable evolution during the observations, and indicate the presence of synchrotron cooling frequency Vc near the upper edge of the optical band. From the broadband spectra we derive an electron energy distribution index p = 2.07 + or - 0.06 and an intrinsic extinction E(B-V)~0.17. Millimeter upper limits are consistent with these derived parameters.
URI: http://hdl.handle.net/2248/1167
???metadata.dc.rights???: © The European Southern Observatory
???metadata.dc.relation.uri???: http://dx.doi.org/10.1051/0004-6361:20034515
Appears in Collections:Publications based on data from IAO, Hanle
IIAP Publications

Files in This Item:
File Description SizeFormat 
Early optical and millimeter observations of GRB 030226 afterglow150.76 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.