GCN Circular 36882

P. A. Evans (U. Leicester), K.L. Page (U. Leicester), C. Salvaggio
(INAF-OAB), T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) reports
on behalf of the Swift-XRT team:

We have analysed 1.7 ks of XRT data for the Swift/BAT-detected burst
GRB 240712A, from 152 s to 5.3 ks after the  Swift/BAT trigger. The
data are entirely in Photon Counting (PC) mode. Using 1421 s of PC mode
data and 2 UVOT images, we find an enhanced XRT position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 122.33591, -37.08814 which is equivalent to:

RA (J2000): 08h 09m 20.62s
Dec(J2000): -37d 05' 17.3"

with an uncertainty of 3.2 arcsec (radius, 90% confidence). This
position is 103 arcsec from the Swift/BAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.9 (+/-0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.5 (+1.1, -1.0). The
best-fitting absorption column is  2.6 (+2.5, -1.7) x 10^22 cm^-2,
consistent with the Galactic value of 8.9 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 9.0 x 10^-11 (1.4 x
10^-10) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     2.6 (+2.5, -1.7) x 10^22 cm^-2
Galactic foreground: 8.9 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.5 (+1.1, -1.0)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01242223.

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