[vsnet-grb-info 17838] GRB 160410A: Swift-XRT refined Analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19282
SUBJECT: GRB 160410A: Swift-XRT refined Analysis
DATE:    16/04/11 05:36:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

B. Sbarufatti (INAF-OAB/PSU), K.L. Page (U. Leicester), C. Pagani (U.
Leicester), A.P. Beardmore (U. Leicester), A. Maselli  (INAF-IASFPA),
A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU),
T.G.R. Roegiers (PSU) and S.L. Gibson report on behalf of the Swift-XRT
team:

We have analysed 5.7 ks of XRT data for GRB 160410A (Gibson et al. GCN
Circ. 19271), from 72 s to 67.9 ks after the  BAT trigger. The data
comprise 241 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 19273).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.54 (+/-0.11).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.28 (+0.12, -0.06). The
best-fitting absorption column is  consistent with the Galactic value
of 1.8 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.9 (+0.8, -0.5) and a best-fitting absorption column
of 2 (+34, -2) x 10^21 cm^-2. The counts to observed (unabsorbed)
0.3-10 keV flux conversion factor deduced from this spectrum  is 3.5 x
10^-11 (3.8 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.8 x 10^20 cm^-2
Intrinsic column:    2 (+34, -2) x 10^21 cm^-2 at z=1.717
Photon index:	     1.9 (+0.8, -0.5)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00682269.

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