GCN Circular 46163
Subject
GRB 261104A: SVOM/ECLAIRs refined analysis
Event
Date
2026-11-05T17:29:51Z (a day ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
R. Hamburg (USRA), M. Brunet (IRAP), F. Piron (LUPM), M.-G. Bernardini (INAF/LUPM), and M. Gnaoui (IAP) 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 261104A (SVOM burst-id sb26110402 – Bernardini et al. 2026, GCN 46150, trigger time T0 = 2026-11-04T20:36:44 UTC).
The burst that triggered ECLAIRs onboard shows a single peak lightcurve with most of the emission seen below 20 keV. The burst duration is T90 = 20.1 +3.3/-3.8 s in the 4-120 keV energy band.
The time-averaged spectrum from T0+7.6 s to T0+27.5 s in the 5-120 keV energy range is best fitted by a power law model with a photon index of -1.76 +/- 0.19. With this model, the 4-120 keV fluence is (1.38 ± 0.43)e-7 erg/cm^2 and the 4-120 keV photon flux is (2.55 ± 0.45)e-1 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: R. Hamburg (USRA) (rhamburg@usra.edu)