GCN Circular 10663
Subject
Swift-BAT refined analysis of trigger 420256
Date
2010-04-23T21:03:08Z (15 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC)
(for the Swift-BAT team):
Using the data set from T-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT trigger #420256 (Hoversten, et al.,
GCN Circ. 10654).
The mask-weighted light curve shows a very weak peak (roughly 5.5 sigma
significance) starting at T_zero and ending at T+65 sec. The spectrum is soft
(simple powerlaw index of 2.89 +- 0.56).
Given the weak detection and the lack of an XRT detection (Circ 10654),
we believe this trigger is not astrophysical. However, we can not rule out
a burst or even a galactic origin.