GRB 200709B

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
HAWC GRB 200709B. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00091

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the HAWC event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

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

J.P. Osborne (U. Leicester), E. Ambrosi  (INAF-IASFPA) , M. Capalbi
(INAF-IASFPA), M. Perri (ASDC), J. D. Gropp (PSU), J.A. Kennea (PSU),
A. Tohuvavohu (U. Toronto), K.L. Page (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 HAWC-detected
burst GRB 200709B in a series of observations tiled on the sky. The
total exposure time is 4.9 ks, distributed over 7 tiles; the maximum
exposure at a single sky location was 1.4 ks. The data were collected
between T0+5.1 ks and T0+16.9 ks, and are entirely in Photon Counting
(PC) mode. 

Two 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 1:
  RA (J2000.0):  252.0755  =  16:48:18.12
  Dec (J2000.0): +15.0921  =  +15:05:31.6
  Error: 5.8 arcsec (radius, 90% conf.)
  Count-rate: 0.0165 [+0.0067, -0.0053] ct s^-1   
  Distance: 1121 arcsec from HAWC position.

Source 3:
  RA (J2000.0):  252.3306  =  16:49:19.35
  Dec (J2000.0): +15.4197  =  +15:25:11.0
  Error: 6.2 arcsec (radius, 90% conf.)
  Count-rate: (7.3 [+4.4, -3.2])e-3 ct s^-1   
  Distance: 791 arcsec from HAWC position.

A catalogued source was 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_GRB00091.

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

A. DAi (INAF/IASFPA), E. Ambrosi (INAF/IASFPA), V. D'Elia (ASDC) report on behalf of the Swift XRT team. 

Swift performed a second observation for the candidate Source 1 present
in the field of GRB 200709B/HAWC-200907A (Osborne  et al., GCN 28072
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 ), 
with a 3.0 ks exposure between T0+52.6 ks and T0+40.0 ks. Source 1 is still 
detected at the same flux level and it is therefore unlikely to be the afterglow. 

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