[vsnet-grb-info 16956] GRB 150902A: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18237
SUBJECT: GRB 150902A: Swift-XRT observations
DATE:    15/09/04 14:55:37 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti at brera.inaf.it>

L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU),
A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), V. D'Elia
(ASDC), A. D'ai (INAF-IASFPA), A. Maselli  (INAF-IASFPA) 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 150902A (Arimoto et al. GCN Circ. 18228),
collecting 4.9 ks of Photon Counting (PC) mode data between T0+59.6 ks
and T0+78.6 ks. 

Two uncatalogued X-ray sources have been detected inside or close to
the Fermi/LAT error region, however none of them is above the RASS
limit or shows definitive signs of fading. Therefore, at the present
time we cannot identify which, if any, is the afterglow. Details of
these sources are given below:

Source 1:
  RA (J2000.0):  214.9797  =  14:19:55.13
  Dec (J2000.0): -69.3535  =  -69:21:12.6
  Error: 4.4 arcsec (radius, 90% conf.)
  Count-rate: 0.0116 +/- 0.0022 ct s^-1
  Flux: (5.16 +/- 0.98)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 2:
  RA (J2000.0):  215.2707  =  14:21:4.97
  Dec (J2000.0): -69.4918  =  -69:29:30.3
  Error: 8.2 arcsec (radius, 90% conf.)
  Count-rate: (5.1 +/- 1.5)e-3 ct s^-1
  Flux: (2.07 +/- 0.62)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

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/00020549.

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