[vsnet-grb-info 2998] GRB 060223B: Swift XRT possible afterglow
GCN Circulars
gcncirc at capella.gsfc.nasa.gov
Sun Feb 26 06:25:06 JST 2006
TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4835
SUBJECT: GRB 060223B: Swift XRT possible afterglow
DATE: 06/02/25 21:22:25 GMT
FROM: Matteo Perri at ISAC/ASDC <perri at asdc.asi.it>
M. Perri, M. Capalbi, L. Vetere (ASDC) L.A. Antonelli (ASDC/INAF-OAR),
G. Tagliaferri (INAF-0AB), D.N. Burrows (PSU) and J.R. Cummings
(GSFC/ORAU) report on behalf of the Swift XRT team:
The Swift XRT began observing the field of GRB 060223B (trigger #192152,
Cummings et al., GCN 4821) at 2006-02-24 14:46:47 UT, approximately 19
hours after the BAT trigger. In a first XRT exposure of ~10 ks we find a
marginal detection (5 net photons, SNR=2) of a faint uncatalogued X-ray
source at the following coordinates:
RA(J2000) = 16h 56m 58.8s
Dec(J2000) = -30d 48' 46" is
with an estimated uncertainty of 10 arcseconds (90% containment).
This position lies 30 arcseconds from the BAT refined position reported
by Fenimore et al. (GCN 4825).
The PSF corrected count rate is (7.5 +/- 3.9)e-4 cts/s, corresponding to
an unabsorbed 0.3-10 keV flux of about 5e-14 erg/cm2/s assuming a
power law spectrum with a photon index of 2 and Galactic absorption
of 1.8e21 cm^-2.
In a second exposure of about 9 ks, starting ~29 hours after the
trigger, the source is not detected.
We note that due to the small number of counts this source could be
a statistical fluctuation of the background and should be regarded as
a possible X-ray afterglow candidate.
This circular is an official product of the Swift XRT Team.
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