NASA SWIFT Mission: GRB 060211B: Swift-BAT detection of a burst

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4739
SUBJECT: GRB 060211B: Swift-BAT detection of a burst
DATE: 06/02/11 16:23:22 GMT
FROM: Scott Barthelmy at NASA/GSFC Scott@lheamail.gsfc.nasa.gov

S. Mateos (U Leicester), S. Barthelmy (GSFC), N. Gehrels (GSFC), O. Godet (U Leicester), C. Hurkett (U Leicster), J. Kennea (PSU), H. Krimm (GSFC/USRA), F. Marshall (GSFC), J. Osborne (U Leicester), K. Page (U Leicester), D. Palmer (LANL) on behalf of the Swift team:

At 15:55:15 UT, Swift-BAT triggered and located GRB 060211B (trigger=181156). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 75.069d,+14.958d {05h 00m 17s,+14d 57′ 27″} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve shows two main peaks starting about 10 sec before the trigger and extending to T+15sec, with a total duration of ~30 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~0 seconds at the trigger.

The XRT began taking data at 15:56:38 UT, 83 seconds after the BAT trigger. The XRT on-board centroid algorithm did not converge and no prompt position is available. The lightcurve shows evidence of a fading source. We are waiting for down-linked data to detect and determine a position for the source.

UVOT took a finding chart exposure of 200 seconds with the V filter starting 84 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7’x2.7′ sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 18th mag. The 8’x8′ region for the list of sources generated on-board covers 100% 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 extinction of about 1.4 magnitudes.