[vsnet-grb-info 8910] GRB 100212A: Swift XRT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10405
SUBJECT: GRB 100212A: Swift XRT refined analysis
DATE:    10/02/13 04:52:41 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe at astro.psu.edu>

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

We have analyzed 1.9 ks of XRT data for GRB 100212A (Grupe et al.
GCN Circ. 10401), from 64 s to 7 ks after the BAT trigger. The
data comprise 409 s in Windowed Timing (WT) mode with the remainder
  in Photon Counting (PC) mode. The enhanced XRT position for this
  burst was given by Osborne et al. (GCN. Circ 10403).

The light curve is complicated displaying several strong flares up
to 700s after the burst. The underlying afterglow light curve
suggests a step decay slope of alpha=2.89+/-0.09. However, the data
of the second orbit indicate the beginning of the plateau phase with
a significantly flatter decay slope. Predictions of the further
development of the X-ray light curve are not reliable at this point.

A spectrum formed from the WT mode data can be fitted with an
absorbed power-law with a photon spectral index of 2.03 (+/-0.03).
  The best-fitting absorption column is 1.97 (+/-0.08) x 10^21 cm^-2,
   in excess of the Galactic value of 1.3 x 10^21 cm^-2 (Kalberla et
   al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux
   conversion factor deduced from this spectrum is 3.8 x 10^-11
   (5.6 x 10^-11) ergs cm^-2 count^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00412081.

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