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GCN Circular 32215

Subject
GRB 220617A: Swift-XRT observations
Date
2022-06-18T10:41:51Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
K.L. Page (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC &
INAF-OAR), V. D'Elia (SSDC & INAF-OAR), J.A. Kennea (PSU), A.
Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), A.P. Beardmore (U.
Leicester) 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 220617A (Di Lalla et al. GCN Circ. 32212Loading...
 
 ),
collecting 4.9 ks of Photon Counting (PC) mode data between T0+23.9 ks
and T0+37.1 ks. 

Five 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.

Please note: due to an error, the original GCN announcing these Swift
observations (GCN 32211Loading...
 
 ) referred to "GRB 220617B", whereas the
observations were of GRB 220617A.

Source 1:
  RA (J2000.0):  157.1531  =  10:28:36.74
  Dec (J2000.0): +15.4493  =  +15:26:57.6
  Error: 6.4 arcsec (radius, 90% conf.)
  Count-rate: (2.7 [+1.5, -1.1])e-3 ct s^-1   
  Distance: 730 arcsec from Fermi/LAT position.
  Flux: (5.5 [+3.0, -2.2])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 2:
  RA (J2000.0):  156.9298  =  10:27:43.15
  Dec (J2000.0): +15.4059  =  +15:24:21.1
  Error: 6.4 arcsec (radius, 90% conf.)
  Count-rate: (1.45 [+0.92, -0.65])e-3 ct s^-1	 
  Distance: 458 arcsec from Fermi/LAT position.

Source 3:
  RA (J2000.0):  157.0400  =  10:28:9.60
  Dec (J2000.0): +15.4886  =  +15:29:19.1
  Error: 6.4 arcsec (radius, 90% conf.)
  Count-rate: (1.67 [+0.91, -0.69])e-3 ct s^-1	 
  Distance: 314 arcsec from Fermi/LAT position.

Source 4:
  RA (J2000.0):  156.9896  =  10:27:57.50
  Dec (J2000.0): +15.4454  =  +15:26:43.4
  Error: 5.7 arcsec (radius, 90% conf.)
  Count-rate: (1.75 [+0.93, -0.70])e-3 ct s^-1	 
  Distance: 321 arcsec from Fermi/LAT position.

Source 5:
  RA (J2000.0):  156.8566  =  10:27:25.60
  Dec (J2000.0): +15.3577  =  +15:21:27.8
  Error: 6.3 arcsec (radius, 90% conf.)
  Count-rate: 0.0114 [+0.0046, -0.0036] ct s^-1   
  Distance: 716 arcsec from Fermi/LAT position.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021505.

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