GCN Circular 40037
Subject
GRB 250403A: Swift-XRT observations
Date
2025-04-04T03:32:07Z (4 days ago)
Edited On
2025-04-04T13:41:38Z (4 days ago)
From
Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>
Via
Web form
S. Dichiara (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB), K.L.
Page and P.A. Evans (U.Leicester) reports on behalf of the Swift-XRT team:
We have analysed 401 s of XRT data for the GRB 250403A detected by
Fermi GBM (Fermi team, GCN circ. 40025) and SVOM/ECLAIRs (SVOM trigger
sb25040305; Julakanti et al., GCN circ. 40026), from T0+7.62 ks to T0+8.02
ks after the SVOM/ECLAIRs trigger. The data are entirely in Photon Counting
(PC) mode.
We find an uncatalogued X-ray source 3.1 sigma above the RASS limit,
consistent with the reported optical counterpart (Starling et al.,
GCN 40028, Chao et al., GCN 40029, Guowang et al., GCN 40031, Li et al., GCN
40032). Details of this source are given below:
Source 1:
RA (J2000.0): 194.6162 = 12:58:27.90
Dec (J2000.0): -24.3800 = -24:22:47.9
Error: 3.7 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: 0.29 (±0.07) ct s-1
Flux: 1.2 (±0.3) ×10-11 erg cm-2 s-1 (observed, 0.3-10 keV)
This XRT position is 2.5 arcsec away from the optical position (Starling et
al., GCN 40028).
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/SVOM/SVOM_FIELD00010/.
This circular is an official product of the Swift-XRT team.