GRB 060115: Swift detection of a burst

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4509
SUBJECT: GRB 060115: Swift detection of a burst
DATE: 06/01/15 13:54:08 GMT
FROM: Scott Barthelmy at NASA/GSFC Scott@lheamail.gsfc.nasa.gov

G. Tagliaferri (INAF-OAB), S. Barthelmy (GSFC), A. Beardmore (U Leicester), D. Burrows (PSU), D. Fox (PSU), N. Gehrels (GSFC), C. Gronwall (PSU), J. Kennea (PSU), F. Marshall (GSFC), D. Palmer (LANL), M. Perri (ASDC) on behalf of the Swift team:

At 13:08:00 UT, Swift-BAT triggered and located GRB 060115 (trigger=177408). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 54.044d,+17.344d {03h 36m 11s,+17d 20′ 38″} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve shows an ~10-sec peak at T_zero. There is a probable second peak at T+90 sec (~20 sec width). The peak count rate was ~1000 counts/sec (15-350 keV), at ~5 seconds after the trigger. We note that this probably long total duration and smooth lightcurve may indicate a high redshift burst.

XRT began observing the field at 13:09:53 UT, 113 sec after the BAT trigger. On-board centroiding found a previously uncatalogued bright fading X-ray source in the field of view at the following coordinates:

RA(J2000) = 03h 36m 08.6s
Dec(J2000)= +17d 20′ 46.3″

This location is 36 arcseconds from the BAT position. The estimated uncertainty is 6 arcseconds (90% confidence radius). The initial flux was 4.1E-9 ergs/cm2/s (0.2-10 keV).

UVOT took a finding chart exposure of nominal 200 seconds with the V filter starting 119 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. Image catalog data are not available at this time. 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 18.0 mag. No correction has been made for the expected visual extinction of about 0.4 magnitudes.