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GCN Circular 5601

GRB 060923C: Swift XRT refined analysis
2006-09-24T00:14:00Z (18 years ago)
Matteo Perri at ISAC/ASDC <>
M. Perri, M. Capalbi, M.L. Conciatore (ASDC), D.N. Burrows (PSU)
and M. Stamatikos (NASA/ORAU) report on behalf of the Swift XRT team:

We have analysed the first four orbits of Swift XRT data on the BAT GRB
060923C (Stamatikos, et al., GCN Circ. 5591). A 5.5 ks Photon Counting
mode image provides a refined XRT position:

RA(J2000)  =  23h 04m 28.49s
Dec(J2000) = +03d 55' 26.6"

with an uncertainty of 5.9" (90% containment). This is 2.4' away from
the center of the BAT refined position (Barthelmy et al., GCN Circ. 5600)
and 6.9" away from the first XRT position quoted in GCN Circ. 5591
(Stamatikos, et al.). This position lies 2.8" from the object reported
by Rau et al. (GCN Circ. 5598).

The 0.3-10 keV X-ray light curve from T+212 s to T+13 ks can be fit by
a broken power law model with temporal break at T+780s (+/-120s) and
decay indices -3.4 (+/-0.2) and -0.6 (+/-0.2) before and after the break,

The X-ray spectrum covering the time period from T+212s to T+275s is
well fit by an absorbed power-law with a photon index of 1.85 (+/-0.13)
and a column density consistent with the Galactic value in the
direction of the burst (5.3e20 cm**-2).

Assuming the X-ray emission continues to decline at the same rate, we
predict a 0.3-10 keV XRT count rate of ~0.01 count/s at T+24hr, which
corresponds to an observed 0.3-10 keV flux of ~5e-13 erg/cm**2/s.

This circular is an official product of the Swift XRT Team.
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