TITLE:   GCN CIRCULAR
NUMBER:  41063
SUBJECT: GRB 250704A: SVOM/ECLAIRs refined analysis
DATE:    25/07/11 12:20:56 GMT
FROM:    SVOM_group <svomgroup@bao.ac.cn>

Authors: N. Dagoneau (CEA), U. Jacob (LUPM), J.X Cao (GXU), Y.H Cheng (SWIFAR, YNU), J.-L. Atteia, M. Brunet, O. Godet (IRAP), F. Cangemi, A. Coleiro (APC)

Using the event-by-event data downloaded through the X-band ground station, we report further analysis of ECLAIRs observations of GRB 250704A (SVOM burst-id sb25070404). 

The burst that triggered ECLAIRs onboard (GCN 40934) consists of a single pulse with a duration of T90 = 9.0 +0.6/-0.5 s in the 4-120 keV energy band.

The time-averaged spectrum of the burst from T0 - 1.50 s to T0 + 7.48 s (T0 = 2025-07-04T03:42:22) in the energy range 8-120 keV is best fit by a power-law model with a photon index of -1.3 +/- 0.2. With this model, the total 4-120 keV fluence, assuming the T90 measured, is 1.23 +/- 0.21 x 10^-6 erg/cm^2.  

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: Nicolas Dagoneau (nicolas.dagoneau at cea.fr)