TITLE: GCN CIRCULAR NUMBER: 46176 SUBJECT: GRB 261103A: SVOM/ECLAIRs refined analysis DATE: 26/11/06 17:56:10 GMT FROM: SVOM_group M. Brunet (IRAP), Y.-H.Cheng (YNU), W.-L.Zhang (PMO) 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 the possible burst GRB 261103A (GCN 46137, trigger time T0 = 2026-11-03T06:51:11 UTC). The event that triggered ECLAIRs onground shows a single peak lightcurve. The burst duration is T90 = 35 +/- 13 s in the 4-20 keV energy band. The time-averaged spectrum from T0-33.8 s to T0+0.8 s in the 5-120 keV energy range is best fitted by a powerlaw model with a photon index alpha = -3 +0.5/-0.8. With this model, the 4-120 keV fluence is (1.4 +/- 0.4)e-7 erg/cm^2 and the 4-120 keV photon flux is 0.32 +/- 0.06 ph/cm^2/s. The spectrum can be equally fitted by a blackbody model with a temperature kT = 2.0 +0.7/-0.5 keV. With this model, the 4-120 keV fluence is (9.7 +/- 2.3)e-8 erg/cm^2 and the 4-120 keV photon flux is 0.23 +0.04/-0.05 ph/cm^2/s. If this event is a GRB, it can be classified as an X-Ray Flash (XRF). 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: M. Brunet (IRAP) (marius.brunet at utoulouse.fr)