Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 9902

GRB 090823: Swift XRT confirmation of the X-ray afterglow
2009-09-08T17:33:53Z (15 years ago)
Dirk Grupe at PSU/Swift-XRT <>
D. Grupe (PSU)  reports on behalf  of the Swift XRT team:

Swift has observed the field of IPN burst GRB090823 (Cummings et
al. GCN Circ. 9835) twice after the initial 4.7 ks observation
on 2009-08-24 (Grupe et al., GCN Circ. 9840) for 9.5 ks on
2009-08-27 and 7.5 ks on 2009-09-05. During the 2009-08-27
observation the X-ray source was clearly detected again at a level
of (2.3+/-0.6)e-3 counts s-1 (about 1.1e-13 ergs s-1 cm-2), roughly
half of the flux during the first observation. During the
2009-09-05 observation however, the X-ray source is definitely
gone and we can only derive a 3-sigma upper limit at a level of
1.9e-3 counts s-1 (9.4e-14 ergs s-1 cm-2). We can confirm that the
source listed in GCN circ. 9840 is the X-ray afterglow of
GRB 090823.
Looking for U.S. government information and services? Visit