TITLE:   GCN CIRCULAR
NUMBER:  10416
SUBJECT: GRB 100213B: Swift XRT refined analysis 
DATE:    10/02/14 05:07:53 GMT
FROM:    Loredana Vetere at PSU  <vetere@astro.psu.edu>

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

We have analysed 1.7 ks of XRT data for GRB 100213B (Vetere et al.
GCN Circ. 10412), from 155 s to 5.7 ks after the BAT trigger. The
data comprise 500 s in Windowed Timing (WT) mode with the remainder
in Photon Counting (PC) mode. Using  1.2ks of XRT Photon Counting
mode data we find a refined XRT position: RA, Dec = 124.28384,
43.44683 which is equivalent to:

RA (J2000): 08h 17m 08.12s
Dec (J2000): +43d 26' 48.6"

with an uncertainty of 4.9 arcsec (radius, 90% confidence).

The light curve can be modelled with a power-law decay with a decay
index of alpha=2.06 (+0.10, -0.08). A spectrum formed from the WT
mode data can be fitted with an absorbed power-law with a photon
spectral index of 1.47 (+/-0.12). The best-fitting absorption column
is 1.3 (+0.4, -0.3) x 10^21 cm^-2, in excess of the Galactic value of
5.9 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 4.9 x 10^-11 (5.6 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index
of 2.06, the count rate at T+24 hours will be 6.9 x 10^-5 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of
3.4 x 10^-15 (3.9 x 10^-15) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00412220.

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