GCN Circular 45259
Subject
GRB 260726A: SVOM/ECLAIRs refined analysis
Event
Date
2026-07-30T23:53:05Z (2 days ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
M. Brunet (IRAP), W. Xie (NAOC), R. Li (YNAO), Z. Wang (BNU) report on behalf of the SVOM/ECLAIRs team.
Using the event-by-event data downloaded through the X-band ground station, we report further analysis of SVOM/ECLAIRs observations of GRB 260726A (SVOM burst-id sb26072614 – GCN 45219 & GCN 45229, trigger time T0 = 2026-07-26T23:45:23UTC), which was also detected by Fermi/GBM (GCN 45218 & GC 45246).
The burst that triggered ECLAIRs onboard shows a single peak lightcurve. The burst duration is T90 = 63 +9/-10 s in the 4-120 keV energy band.
The time-averaged spectrum from T0-23.3 s to T0+35.9 s in the 5-120 keV energy range is best fitted by a powerlaw with an exponential cutoff model with alpha = -1.30 +0.23/-0.18 and a peak energy = 58 +57/-18 keV. With this model, the 4-120 keV fluence is (1.1 +/-0.1)e-6 erg/cm^2 and the 4-120 keV photon flux is 0.61+/-0.03 ph/cm^2/s.
All the quoted errors are at the 68% confidence level.
The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC.
The SVOM/ECLAIRs point of contact for this burst is: Marius Brunet (IRAP) (marius.brunet at utoulouse.fr)