NASA Swift Mission: GRB 060219: Swift-BAT detection of a weak burst

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4788
SUBJECT: GRB 060219: Swift-BAT detection of a weak burst
DATE: 06/02/19 23:14:53 GMT
FROM: Scott Barthelmy at NASA/GSFC Scott@lheamail.gsfc.nasa.gov

A. Moretti (OAB/INAF), S. Barthelmy (GSFC), D. Burrows (PSU), J. Cummings (GSFC/ORAU), N. Gehrels (GSFC), S. Hunsberger (PSU), C. Markwardt (GSFC/UMD), F. Marshall (GSFC), D. Palmer (LANL), T. Sakamoto (GSFC/ORAU) on behalf of the Swift team:

At 22:48:05 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060219 (trigger=191512). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 241.806,+32.330 deg {16h 07m 14s, +32d 19′ 49″} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a weak single peak with a duration of ~10 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger.

The XRT began taking data at 22:50:05 UT, 120 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image and no prompt position is available. The prompt spectrum and lightcurve are consistent with a weak, possibly fading source in the field of view. 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 121 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 0.1 magnitudes.