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GCN Circular 25125

Subject
GRB 190719C: Swift-XRT refined Analysis
Date
2019-07-20T15:22:02Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne
(U. Leicester), M.G. Bernardini (INAF-OAB), M. Capalbi (INAF-IASFPA),
D.N. Burrows (PSU), J. D. Gropp (PSU), A. Tohuvavohu (PSU) and E.
Ambrosi report on behalf of the Swift-XRT team:

We have analysed 2.4 ks of XRT data for GRB 190719C (Ambrosi et al. GCN
Circ. 25106), from 64 s to 52.0 ks after the  BAT trigger. The data
comprise 353 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The refined XRT position is RA, Dec =
240.2069, +13.0000 which is equivalent to:

RA (J2000): 16 00 49.65
Dec(J2000): +13 00 00.0

with an uncertainty of 3.6 arcsec (radius, 90% confidence). a rise,
withpower-law index .

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.42 (+0.04, -0.03). The
best-fitting absorption column is  2.26 (+0.19, -0.18) x 10^21 cm^-2,
in excess of the Galactic value of 4.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.54 (+0.29, -0.25)
and a best-fitting absorption column of 9.0 (+9.8, -4.3) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.5 x 10^-11 (5.0 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     9.0 (+9.8, -4.3) x 10^20 cm^-2
Galactic foreground: 4.7 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.54 (+0.29, -0.25)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00915381.

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