TITLE:   GCN CIRCULAR
NUMBER:  6130
SUBJECT: GRB 070223: Swift-XRT Refined Analysis
DATE:    07/02/23 11:01:49 GMT
FROM:    Loredana Vetere at PSU  <vetere@astro.psu.edu>

L. Vetere (PSU) reports on behalf of the Swift-XRT team:

We have analysed the first four orbits (up to 16.5 ks after the BAT trigger) of
Swift XRT data for  GRB 070223 (Vetere et al., GCN 6126). Using ~2.8 ks of
Photon Counting (PC) mode data we find the following refined position:

RA (J2000)  =  10h 13m 48.4s
Dec(J2000)  = +43d 07' 58.2"

with an error radius of 4.5 arcseconds (90% confidence). This is 4.4 arcsec away
from  XRT initial position and 4.1 arcsec from the possible optical candidate
reported by A. Melandri (GCN 6127).

The WT lightcurve shows a rapid decay with a slope of alpha~2.3 while the PC
light curve shows a possible flattening (~0.6) but we still need more data to
confirm it.

The WT mode spectrum can be fitted with a single power law of photon index of
1.7 +/- 0.1 and column density of (4.5 +/-0.1 )e21 cm**-2. We note the Galactic
column density in the direction of the source is 1.1e20 cm**-2.
The 0.3-10 keV observed flux was 6.5e-10 ergs cm**-2 s**-1, which corresponds to
an unabsorbed flux of 9.2e-10 ergs cm**-2 s**-1.

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