TITLE:   GCN CIRCULAR
NUMBER:  19162
SUBJECT: GRB 160310A: Swift-XRT observations
DATE:    16/03/10 18:58:39 GMT
FROM:    Alessandro Maselli at INAF/IASF Palermo  <maselli@ifc.inaf.it>

S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea
(PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT
team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 160310A (Vianello et al. GCN Circ. 19158),
collecting 3.0 ks of Photon Counting (PC) mode data between T0+40.3 ks
and T0+46.7 ks. 

One uncatalogued X-ray source has been detected inside or close to the
Fermi/LAT error region, it is below the RASS limit and shows no
definitive signs of fading. Therefore, at the present time we cannot
confirm this as the afterglow. Details of this source are given below:

Source 2:
  RA (J2000.0):  98.8226  =  06:35:17.42
  Dec (J2000.0): -7.2156  =  -07:12:56.1
  Error: 5.1 arcsec (radius, 90% conf.)
  Count-rate: (5.2 +/- 1.9)e-3 ct s^-1
  Flux: (1.18 +/- 0.43)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Another uncatalogued was also detected, however this was too far from
the GRB position to be the afterglow.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020602.

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