GCN Circular 36478

M. Ferro (INAF-OAB), R. Brivio (INAF-OAB), A. Tohuvavohu (U. Toronto),
D.N. Burrows (PSU), J. D. Gropp (PSU), A.P. Beardmore (U. Leicester),
J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA) and P.A. Evans (U.
Leicester) reports on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 240513A in a series of observations tiled
on the sky. The total exposure time is 5.1 ks, distributed over 7
tiles; the maximum exposure at a single sky location was 1.6 ks. The
data were collected between T0+46.1 ks and T0+80.7 ks, and are entirely
in Photon Counting (PC) mode. 

Three uncatalogued X-ray sources have been detected, 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 2:
  RA (J2000.0):  163.8237  =  10:55:17.69
  Dec (J2000.0): -27.6225  =  -27:37:20.9
  Error: 9.7 arcsec (radius, 90% conf.)
  Count-rate: (8.6 [+4.8, -3.5])e-3 ct s^-1   
  Distance: 1422 arcsec from Fermi/LAT position.

Source 4:
  RA (J2000.0):  163.9338  =  10:55:44.10
  Dec (J2000.0): -27.5934  =  -27:35:36.2
  Error: 7.6 arcsec (radius, 90% conf.)
  Count-rate: (7.4 [+4.8, -3.4])e-3 ct s^-1   
  Distance: 1736 arcsec from Fermi/LAT position.

Source 6:
  RA (J2000.0):  163.4544  =  10:53:49.05
  Dec (J2000.0): -27.4116  =  -27:24:41.7
  Error: 5.1 arcsec (radius, 90% conf.)
  Count-rate: 0.0224 [+0.0072, -0.0060] ct s^-1   
  Distance: 362 arcsec from Fermi/LAT position.
  Flux: (1.64 [+0.53, -0.44])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 https://www.swift.ac.uk/xrt_products/TILED_GRB00125.

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