[vsnet-grb-info 27269] GRB 140330A: Swift-XRT refined Analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29372
SUBJECT: GRB 140330A: Swift-XRT refined Analysis
DATE:    21/01/29 14:52:21 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU),
D.N. Burrows (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), T.
Sbarrato (INAF-OAB) and  report on behalf of the Swift-XRT team: report
on behalf of the Swift-XRT team:

We have analysed 3.2 ks of XRT data for the Fermi/LAT-detected burst
GRB 140330A, from 102.0 ks to 120.0 ks after the  Fermi/LAT trigger.
The data are entirely in Photon Counting (PC) mode. The refined XRT
position is RA, Dec = 325.4425, -64.1882 which is equivalent to:

RA (J2000): 21 41 46.19
Dec(J2000): -64 11 17.4

with an uncertainty of 4.0 arcsec (radius, 90% confidence). This
position is 7.7 arcmin from the Fermi/LAT position.  The source has a
mean count rate of 2.4e-02 ct/sec; we cannot determine at the present
time whether it is fading.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.8 (+0.7, -0.5). The
best-fitting absorption column is  9 (+17, -5) x 10^20 cm^-2,
consistent with the Galactic value of 3.5 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 3.4 x 10^-11 (4.1 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     9 (+17, -5) x 10^20 cm^-2
Galactic foreground: 3.5 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.8 (+0.7, -0.5)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020372.

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