GRB 080524
GCN Circular 7774
Subject
GRB 080524: Swift-BAT detection of a burst in ground analysis
Date
2008-05-25T19:41:39Z (17 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
G. Sato (GSFC/ISAS), L. Barbier (GSFC), S. Barthelmy (GSFC),
W. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
At 04:13:00 UT on May 24, 2008, BAT triggered on GRB 080524. The onboard
processing found a source that was not significant enough to initiate a
burst response. Routine processing on the ground of failed triggers found
a significant source (9.7 sigma) at RA, Dec 268.449, +80.143 which is:
RA 17h 53m 47.7s (J2000)
Dec 80d 8m 35s (J2000)
with an uncertainty radius of 2.5 arcmin (90% containment). The source
was 58% coded.
T90 was 9 +- 2 sec. The peak count rate was 600 counts/sec (15-350 keV).
Using the data set from T-2 to T+8 sec, the mask-weighted light curve
shows a single roughly symmetrical peak.
The power-law index of the time averages spectrum is 1.1 +- 0.2. The
fluence in the 15-150 keV range from T-2 to T+8 sec was
(2.9 +- 0.5) x 10-07 ergs/cm2. The 1-sec peak flux was 0.4 +- 0.2
counts/cm2/sec. All uncertainties are 90% confidence.
Swift is executing a TOO to the position of this burst, and preliminary
XRT and UVOT results should be available in a few hours.
GCN Circular 7776
Subject
GRB 080524: Swift XRT and UVOT analysis
Date
2008-05-28T19:35:41Z (17 years ago)
From
Dirk Grupe at PSU/Swift-XRT <grupe@astro.psu.edu>
Dirk Grupe (PSU), Paul Kuin (MSSL), Jay Cummings (GSFC), and Kim Page (U
Leicester) report of behalf of the Swift team:
Swift observed the field of GRB 080524 (Sato et al., GCN Circ. 7774) as
a Target
of Opportunity for 10 ks starting on 2008-05-25 at 16:43:45 UT, 36h 30m
after
the burst. The exposures in XRT and UVOT V were 8.9 and 9.7 ks,
respectively.
Within the 2.5' BAT error circle no new source was found. In XRT the 3sigma
upper limit is in the 0.5-8.0 keV band is 1.1e-3 counts/s which converts to
roughly 4.7e-14 ergs/s/cm2 in the 0.3-10.0 keV band assuming an
absorbed power law model with Galactic NH (5.19e20 cm-2) and a canonical
X-ray
Photon index Gamma=2.0.
The 3sigma upper limit in the UVOT V-Filter is 20.0 mag.
No further Swift observations are planned for this GRB.
This circular is an official product of the Swift team.