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GCN Circular 18250

GRB 150907A: Swift-XRT observations
2015-09-08T00:52:27Z (9 years ago)
Tineke Roegiers at PSU <>
J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), T.G.R. Roegiers (PSU),
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. D'ai
(INAF-IASFPA), A. Maselli  (INAF-IASFPA), A. Melandri (INAF-OAB), D.N.
Burrows (PSU) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 150907A (Nakagawa et al. GCN Circ. 18246) in a series of
observations tiled on the sky. The total exposure time is 1.7 ks,
distributed over 4 tiles; the maximum exposure at a single sky location
was 1.1 ks. The data were collected between T0+8.8 ks and T0+18.8 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):  225.0526  =  15:00:12.62
  Dec (J2000.0): -47.7084  =  -47:42:30.3
  Error: 6.0 arcsec (radius, 90% conf.)
  Count-rate: 0.037 +/- 0.010 ct s^-1
  Flux: (2.50 +/- 0.70)e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at

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