B.-B. Zhang (PSU/UAH), S. D. Barthelmy (GSFC), M. M. Chester (PSU), D. Grupe (PSU),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA), S. R. Oates (MSSL-UCL), H. A. Krimm (USRA/CRESST/GSFC),
J. A. Kennea (PSU), Daniele Malesani (DARK/NBI), M. H. Siegel (PSU) and F. E. Marshall (NASA/GSFC)
report on behalf of the Swift Team:
At 11:37:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130725A (trigger=563980). Swift slewed to the burst.
This burst was not identified in real-time due to telemetry gaps.
The BAT on-board calculated location is
RA, Dec 230.034,+0.624 which is
RA(J2000) = 15h 20m 8s
Dec(J2000) = +00d 37' 26"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single-peaked
structure with a duration of about 15 sec. The peak count rate
was ~600 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 12:28:46 UT, 3094 seconds after
the BAT trigger. Using 2.28 ks of ground-linked XRT data, we found an
uncatalogued X-ray source located at RA, Dec = 230.033,+0.627, which is
RA(J2000) = +15h 20m 07.92s
Dec(J2000) = 00d 37' 40.2"
with an uncertainty of 4.0 arc seconds (radius, 90% containment).
UVOT took a finding chart exposure of 150 seconds with the White filter 3097 seconds after
the BAT trigger. No credible 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 19.6 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 18 mag. No correction has been
made for the expected extinction corresponding to E(B-V) of 0.06.
Further analysis is on-going. This circular is an official product of the Swift team.