[vsnet-grb-info 19374] GRB 170510A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21086
SUBJECT: GRB 170510A: Swift-XRT observations
DATE:    17/05/10 22:22:51 GMT
FROM:    Antonino D'Ai at IASF-PA  <antonino.dai at ifc.inaf.it>

A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows
(PSU), A. Cholden-Brown (PSU), S.L. Gibson (U. Leicester), J.P. Osborne
(U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) 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 170510A (Bissaldi et al. GCN Circ. 21080)
in a series of observations tiled on the sky. The total exposure time
is 4.7 ks, distributed over 7 tiles; the maximum exposure at a single
sky location was 1.4 ks. The data were collected between T0+24.3 ks and
T0+36.2 ks, and are entirely in Photon Counting (PC) mode. 

One uncatalogued X-ray source has been detected, 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 1:
  RA (J2000.0):  160.15394  =  10:40:36.95
  Dec (J2000.0): -39.21244  =  -39:12:44.8
  Error: 2.3 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0630 [+0.0091, -0.0090] ct s^-1   
  Distance: 794 arcsec from Fermi/LAT position.
  Flux: (1.76 [+0.26, -0.25])e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Two catalogued sources were also detected.

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00067.

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