TITLE:   GCN CIRCULAR
NUMBER:  44848
SUBJECT: GRB260603A: SVOM/ECLAIRs refined analysis
DATE:    26/06/06 09:24:50 GMT
FROM:    SVOM_group <svomgroup@bao.ac.cn>

M. Brunet (IRAP),N. Dagoneau (CEA), Donghua ZHAO, Wenjin Xie (NAOC), Ruizhi Li (YNAO), Ziming 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 260603A (SVOM burst-id sb26060303 – GCN 44787, trigger time T0 = 2026-06-03T05:38:16 UTC).

The burst that triggered ECLAIRs onboard shows a single peak lightcurve. The burst duration is T90 = 101 +4/-7 s in the 4-120 keV energy band.

The time-averaged spectrum from T0-51.0 s to T0+50.7 s in the 5-120 keV energy range is best fitted by a powerlaw model with alpha = -1.75 +0.08/-0.09. With this model, the 4-120 keV fluence is (1.33 +0.11/-0.12)e-6 erg/cm^2 and the 4-120 keV photon flux is 0.47 +0.02/-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)