TITLE:   GCN CIRCULAR
NUMBER:  35054
SUBJECT: GRB 231115A: archival Chandra X-ray observations
DATE:    23/11/16 05:14:29 GMT
FROM:    Albert Kong at NTHU <akhkong@gmail.com>

A.K.H. Kong (NTHU), K.-L. Li (NCKU) report:

Following the discovery of GRB 231115A (GCN 35035) in the direction of M82 and its optical counterpart candidate AT 2023xvj (GCN 35041), we searched for X-ray emission from the progenitor with the Chandra X-ray Observatory. Chandra observed M82 with the ACIS detector 32 times between 2000 and 2016, with a total exposure time of about 561 ks. We combined all the observations and no source is visible at the position of the optical transient. We derive a 3-sigma luminosity limit of 2.3e37 erg/s (0.3-10 keV; D=3.5 Mpc) by assuming an absorbed power-law model with a photon index of 2.