GCN Circular 36884

M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), J.A. Kennea
(PSU), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), B. Sbarufatti (INAF-OAB) and P.A.
Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the SVOM-detected
burst GRB 240713A in a series of observations tiled on the sky. The
total exposure time is 4.0 ks, distributed over 1 tiles; the maximum
exposure at a single sky location was 4.0 ks. The data were collected
between T0+142.7 ks and T0+156.3 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. 
Source 3 is consistent in position and flux with EP J233058.2+015317,
identified by EP-FXT in their follow-up observations (GCN 36859
Not found
 
 
). The
consistent flux between the two detections suggest that the source is
not fading. Moreover, source 3 is spatially consistent with a
catalogued 2MASS source (2MASS J23305766+0153156). 
Source 2 is spatially consistent and can be associated to a catalogued
quasar (SDSS J233053.58+014603.0). 
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):  352.7279  =  23:30:54.70
  Dec (J2000.0): +1.9401  =  +01:56:24.5
  Error: 6.7 arcsec (radius, 90% conf.)
  Count-rate: (1.55 [+1.06, -0.76])e-3 ct s^-1	 
  Distance: 541 arcsec from SVOM position.

Source 2:
  RA (J2000.0):  352.7219  =  23:30:53.25
  Dec (J2000.0): +1.7664  =  +01:45:59.2
  Error: 7.4 arcsec (radius, 90% conf.)
  Count-rate: (1.63 [+1.13, -0.80])e-3 ct s^-1	 
  Distance: 626 arcsec from SVOM position.

Source 3:
  RA (J2000.0):  352.7404  =  23:30:57.69
  Dec (J2000.0): +1.8868  =  +01:53:12.6
  Error: 6.1 arcsec (radius, 90% conf.)
  Count-rate: (2.33 [+1.24, -0.94])e-3 ct s^-1	 
  Distance: 541 arcsec from SVOM position.
  Flux: (6.3 [+3.3, -2.5])e-14 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 https://www.swift.ac.uk/xrt_products/TILED_GRB00126.

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