Status Report

GRB 060109: Swift Detection of a long burst

By SpaceRef Editor
January 10, 2006
Filed under , ,
GRB 060109:  Swift Detection of a long burst

NUMBER: 4455
SUBJECT: GRB 060109: Swift Detection of a long burst
DATE: 06/01/09 17:31:48 GMT
FROM: Jay R. Cummings at NASA/GSFC/Swift

M. De Pasquale (MSSL), S. Barthelmy (GSFC), A. Beardmore (U. Leicester), J. Cummings (GSFC/ORAU), N. Gehrels (GSFC), M.R. Goad (U. Leicester), O. Godet (U. Leicester), J. Kennea (PSU), H. Krimm (GSFC/USRA), F. Marshall (GSFC), K. Page (U. Leicester), D. Palmer (LANL), T. Sakamoto (GSFC), on behalf of the Swift Team:

At 16:54:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060109 (trigger=176620). The BAT on-board calculated location is RA,Dec 282.710, +31.989 {18h 50m 50s, +31d 59′ 22″} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 10 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~8 sec after the trigger.

The XRT began observing the burst at 16:56:22 UT, 101 sec after the BAT trigger. A bright (0.2-10 keV flux of 4.8e-09 erg/cm2/sec), fading, uncatalogued source was found by the on-board centroiding algorithm at

RA(J2000)= 18h 50m 43.9s
DEC(J2000)= +31d 59′ 34.7″

with an uncertainty of 5.8 arcsec radius (90% containment). This uncertainty includes a systematic error of about 5 arcsec in the on-board calculated positions due to the XRT boresight offset. This position lies 84 arcsec from the centre of the BAT error circle.

UVOT took a finding chart exposure of 200 seconds with the V filter starting 104 sec after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7’x2.7′ sub-image covers 100% of the XRT 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 XRT error circle. The list of sources is typically complete to about 19.0 mag. No correction has been made for the expected visual extinction of about 0.5 magnitudes.

SpaceRef staff editor.