Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 4923

SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
2006-03-26T19:22:53Z (18 years ago)
Scott Barthelmy at NASA/GSFC <>
G. Sato (ISAS), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), 
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC),
J. Tueller (GSFC), L. Vetere (ASDC)
on behalf of the Swift-BAT team:

Using the full data set from recent telemetry downlinks, we report
further analysis of Swift-BAT detection of SGR 1900+14 (trigger #202746)
(Vetere, et al., GCN 4922).  T90 is 48 +- 4 msec.  The partial coding
fraction is 33%.  The lightcurve is a single FRED-like peak wih a decay
of ~16 msec.  The BAT spectrum is well fitted with a blackbody model:
kT = 17.5 -7.9,+15.7 keV (90% confidence).  The reduced chi-squared
is 0.95 for 57 degrees of freedom.  The spectral parameters are consistent
with the HETE-2 observation of the 2001 middle-class burst of SGR 1900 
(see Fig.5 of Olive et al. ApJ 616 (2004) 1148 (astro-ph/0403162)).

There are 4 other BAT detections from this source (two before the 
original triggered detection, and two after):
   Date       Time       Comment
   2006-03-25 10:12:05   Roughly 4 times brighter than the 20:16:40 outburst
   2006-03-25 18:07:21   Roughly 2 times brighter than the 20:16:40 outburst
   2006-03-25 20:16:40   Triggered detection
   2006-03-25 23:34:08   Comparable to 20:16:40 in brightness
   2006-03-26 00:59:23   Comparable to 20:16:40 in brightness

We note that the 4th & 5th events occurred during TOO follow-up observations
of the SGR 1900+14 source.
Looking for U.S. government information and services? Visit