[vsnet-grb-info 3293] GRB060512: Swift XRT Team refined analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5128
SUBJECT: GRB060512: Swift XRT Team refined analysis
DATE:    06/05/13 12:14:51 GMT
FROM:    Olivier Godet at U.of Leicester  <og19 at star.le.ac.uk>

O. Godet, K.L. Page (U. Leicester), D. N. Burrows (PSU) report on behalf
of the Swift XRT team:

We have analysed the Swift XRT data of GRB 060512 from the
first 5 orbits (~8.8 ks). The refined coordinates on ground are:

RA(J2000) =  13h 03min 05.8s
Dec(J2000) = +41d 11' 28.3"

with an uncertainty of 3.6 arc-seconds radius (90% containment).  This
position is consistent with that reported by Cummings et al. (GCN 5117).
The refined position is also consistent with the optical position given
by the UVOT (GCN 5117) and the 2-m Liverpool Telescope (Mundell et al.,
GCN 5118).

The WT and PC light-curve show a decay with a temporal index of -1.3
+/-0.04 on which is superposed a flare peaking at around 200 s after the
BAT trigger (T0). We note that the decay part of a flare could be also
seen in the WT data (from T0+102s to T0+150s).

Due to the low statistics of the PC and WT data, the data are poorly
constrained with an absorbed power-law. However, the spectra of the WT
data and the first orbit of PC data (containing the flare) are clearly
soft with Gamma > 3 and nH = 4.9 + 6.0/-4.5 e20 cm^-2. Note that this
nH-value is consistent with the Galactic absorbing column of 1.4e20
cm^-2. The spectrum of the late PC data (from T0+3000s to T0+24,000s)
has a spectral slope of 1.93+/0.18 fixing the absorbing column to the
Galactic one.

If the light-curve is still unbroken at T0+24 h, the predicted count
rate will be 0.0014 counts/s (corresponding to an unabsorbed 0.3-10 keV
flux of 6.6e-14 erg cm^-2 s^-1).

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