GRB060108: Swift detection of its 100th GRB
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4443
SUBJECT: GRB060108: Swift detection of its 100th GRB
DATE: 06/01/08 15:11:49 GMT
FROM: Hans Krimm at NASA-GSFC krimm@milkyway.gsfc.nasa.gov
S. Oates (UCL-MSSL), D. Burrows (PSU), M. De Pasquale (UCL-MSSL), N. Gehrels (GSFC), J. Kennea (PSU), H. Krimm (GSFC/USRA), K. Page (U. Leicester), F. Marshall (GSFC), S.T. Holland (GSFC/USRA), D. Palmer (LANL), A. Parsons (GSFC) report on behalf of the Swift team:
At 14:39:11.76 UT, Swift-BAT triggered and located GRB060108 (trigger=176453). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 146.992d, +31.916d {09h 47m 58s, +31d 54′ 59″} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve showed a single peak structure with a FRED time profile and a total duration of ~20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~4 seconds after the trigger.
XRT started observing the field at 14:40:43 UT, 91 seconds after the BAT trigger. Although no source was found by the on-board algorithm, the raw X-ray light-curve implies there is a fading source in the field of view. However, we will have to wait for the Malindi data to determine the position of this source.
UVOT took a finding chart exposure of 200 seconds with the V filter starting 91 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7’x2.7′ sub-image covers 19% of the BAT error circle. The 3-sigma upper limit is 18.3 mag. The 8’x8′ region for the list of sources generated on-board covers 87% of the BAT error circle. The list of sources is typically complete to about 18.0 mag. No correction has been made for the expected visual extinction of about 0.1 magnitudes.
