GCN Circular 43527
Subject
GRB 260125A: Swift-XRT observations
Event
Date
2026-01-27T15:36:17Z (8 days ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), S. Dichiara (PSU), J.A.
Kennea (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P.
Beardmore (U. Leicester), S. Campana (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
Fermi/GBM-detected burst GRB 260125A (Fermi GBM Team, GCN 43510),
collecting 3.1 ks of Photon Counting (PC) mode data between T0+64.9 ks
and T0+86.3 ks.
No X-ray sources have been detected consistent with the GOTO
counterpart position (Gompertz et al., GCN 43514). The 3-sigma upper
limit in the field is 0.003 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 1.0e-13 erg cm^-2 s^-1 (assuming a typical GRB
spectrum).
Five uncatalogued sources were detected too far from the GOTO position,
and not showing significant signs of fading to be likely afterglow
candidates.
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/00021899.
This circular is an official product of the Swift-XRT team.