GCN Circular 17453

V. Mangano (PSU), M.C. Stroh (PSU), B.P. Gompertz (U. Leicester), J.P.
Osborne (U. Leicester), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA),
A. Maselli  (INAF-IASFPA), 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
Fermi/LAT-detected burst GRB 150210A (Zhu et al. GCN Circ. 17438
Not found
 
 
) in a
series of observations tiled on the sky. The total exposure time is 7.3
ks, distributed over 4 tiles; the maximum exposure at a single sky
location was 4.3 ks. The data were collected between T0+66.9 ks and
T0+95.4 ks, and are entirely in Photon Counting (PC) mode. 

No uncatalogued X-ray sources have been detected. The 3-sigma upper
limit in the field (not including the regions where the tiles overlap)
ranges from ~0.004 to ~0.008 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 1.5e-13 to 3.3e-13 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

A previously-catalogued X-ray source has been detected, however because
it is a catalogued object it is unlikely to be the afterglow.

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_GRB00040.

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