[vsnet-grb-info 4461] GRB 070330: Swift-XRT refined analysis

GCN Circulars gcncirc at capella.gsfc.nasa.gov
Sat Mar 31 13:43:37 JST 2007


TITLE:   GCN CIRCULAR
NUMBER:  6234
SUBJECT: GRB 070330: Swift-XRT refined analysis 
DATE:    07/03/31 04:43:32 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe at astro.psu.edu>

GRB 070330: Swift-XRT refined analysis

D. Grupe (PSU) reports on behalf of the Swift/XRT team



We have analyzed the first two orbits of GRB 070330 (Grupe et al., GCN 
6232)
with total observing times of 2.7 ks in photon counting mode in the 
Swift XRT.
The Photon Counting mode image provides a refined XRT position at
Ra, Dec= 269.5407, -63.7934, which is

RA(J2000) = 17h 58m 09.8s
Dec(J2000) = -63d 47' 36.1"

with an error of 3.6" (90% confidence). This position is 0.4"
away from the preliminary XRT position reported in GCN 6232.

The X-ray light curve displays  a flare at the beginning of the
XRT observation with a peak at about 230s after the burst. The decay 
slope after
the flare is 1.10+/-0.12. The prediction 24h after the burst is a 
0.3-10.0 keV
flux of 6e-14 ergs/s/cm2 or about 1.3e-3 XRT counts/s.

The photon counting mode data can be fitted by a single absorbed power law
model with a photon index Gamma=1.72+/-0.11 and an absorption column 
density
consistent with the Galactic value (7.14e20 cm^-2; Dickey & Lockman, 1990).


More analysis of the data will be presented in the
GCN report.

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



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