GCN Circular 40123
Subject
EP250407a: Swift-XRT observations
Date
2025-04-08T19:20:26Z (15 days ago)
From
Maia Williams at PSU <mjw6837@psu.edu>
Via
Web form
M. A. Williams (PSU), S. Dichiara (PSU), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
We have analyzed 2100 s of XRT data for the recently reported transient EP250407a (GCN #40118), from T0+36.5 ks to T0+42.4 ks after detection by Einstein Probe WXT. The data are entirely in Photon Counting (PC) mode.
No X-ray sources have been detected within the estimated 90% EP-WXT error region (2.5 arcmin), with an upper limit on count rate of 5.3 × 10^-3 ct/s. For a typical GRB-like spectrum, this equates to an upper limit on flux of 2 x 10^-13 erg/s/cm^2 (0.3-10 keV).
The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/EP/EP_FIELD00033/.