GCN Circular 3419
Subject
Refined Chandra analysis of GRB 050509b
Event
Date
2005-05-12T22:43:26Z (21 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
S. Patel, C. Kouveliotou (MSFC), D. N. Burrows, D. Grupe (PSU), N. Gehrels
(GSFC), P. Meszaros (PSU), B. Zhang (UNLV), and R. Wijers (U. Amsterdam)
report:
Further analysis of our 50 ks Chandra observation of GRB 050509b (Burrows
et al. 2005; GCN 3415) has shown that the XRT error circle is embedded in
the diffuse X-ray emission from the cluster NSC J123610+285901. We find
that the two X-ray sources reported in GCN 3415 are due to fluctuations in
the counts from the cluster emission and are spurious. Our refined
analysis finds no Chandra point sources within the XRT error circle down to
an estimated 99% unabsorbed flux upper limit of about
1.2 x 10e-15 ergs s^-1 cm^-2 (0.5-10.0 keV; assuming galactic column density
1.52e20 cm^-2 and spectral photon index of -2).