[vsnet-grb-info 25711] GRB 200524A: Swift-XRT afterglow detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27811
SUBJECT: GRB 200524A: Swift-XRT afterglow detection
DATE:    20/05/25 04:14:56 GMT
FROM:    Kim Page at U.of Leicester  <klp5 at leicester.ac.uk>

M. Capalbi (INAF-IASFPA), M. Perri (ASDC), V. D'Elia (ASDC), A.
Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P.
Osborne (U. Leicester), 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
Fermi/LAT-detected burst GRB 200524A (Fana Dirirsa et al. GCN Circ.
27797), collecting 5.0 ks of Photon Counting (PC) mode data between
T0+36.4 ks and T0+55.7 ks. 

Four uncatalogued X-ray sources are detected, of which one ("Source 6")
is  believed to be the afterglow. Using 1644 s of PC mode data and 1
UVOT image, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 213.04474, +60.90538 which is equivalent to:

RA (J2000): 14h 12m 10.74s
Dec(J2000): +60d 54' 19.4"

with an uncertainty of 4.4 arcsec (radius, 90% confidence). This
position is 9.2 arcmin from the Fermi/LAT position, and 3 arcsec from
ZTF20abbiixp (Ho et al., GCN 27799).

The light curve can be modelled with a power-law decay with a decay
index of alpha=3.42 (+0.06, -2.83).

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021001.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021001.

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