TITLE: GCN CIRCULAR NUMBER: 39734 SUBJECT: GRB 250314A: Swift XRT Detection DATE: 25/03/15 14:08:48 GMT FROM: Jamie Kennea at Penn State jak51@psu.edu
J. A. Kennea (PSU), V. D'Elia (SSDC & INAF-OAR), P. A. Evans (Leicester) report on behalf of the Swift/XRT Team
At 14:28UT on March 14, 2024 Swift began a Target-of-Opportunity observation of GRB 250314A, a SVOM ECLAIRs detected GRB (GCN #39719). Swift finds a uncatalogued point source inside the ECLAIRS error region at the following position: RA(J2000) = 201.30136, -5.2823:
RA(J2000) = 13h 25m 12.22s, Dec(J2000) = -05h 16' 56.1'',
with an estimated uncertainty of 3.5 arc-seconds radius (90% confidence). This position matches the reported optical counterpart (GCN #39727) with a reported redshift of z = 7.21 (GCN #39732). The XRT source has a peak flux of 2.2 x 10^-12 erg/s/cm^2 (0.3 - 10 keV).
As Swift has performed only a single observation, we cannot confirm fading. We note also the presence of 2 other X-ray sources in the XRT field of view, source #2 lies at the edge of the ECLAIRs error region, source #3 lies outside. Given reported observations of source #1 and it's redshift, we do not believe these sources are credible afterglow candidates:
Source no: 2 RA (J2000): 201.33727 [degrees] = 13h 25m 20.94s Dec (J2000): -5.16436 [degrees] = -05d 09' 51.7" Error: +4.8 [arcsec, 90% conf. radius] Flag: Good
Source no: 3 RA (J2000): 201.44746 [degrees] = 13h 25m 47.39s Dec (J2000): -5.27117 [degrees] = -05d 16' 16.2" Error: +5.3 [arcsec, 90% conf. radius] Flag: Good
View this GCN Circular online at https://gcn.nasa.gov/circulars/39734. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...