GCN Circular 38123
Subject
GRB 241105A: SVOM/GRM observation
Date
2024-11-08T06:34:21Z (2 months ago)
From
zhengchao_astro@foxmail.com
Via
Web form
SVOM/GRM team: Chao Zheng, Chen-Wei Wang, Shi-Jie Zheng, Yong-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zhang, Wen-Jun Tan, Jin-Peng Zhang, Yue Wang, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP), JeanLuc Attéia (IRAP)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV)
Report on behalf of the SVOM team:
During the commissioning phase, the SVOM/GRM was triggered in-flight by GRB 241105A (SVOM trigger reference: sb24110502) at 2024-11-05T16:06:05.00 UT (T0), which was also observed by Fermi/GBM (Fermi GBM Team, GCN 38085), Konus-Wind (D. Frederiks et al., GCN 38103), and Swift/BAT (J. DeLaunay et al., GCN 38108).
The real-time alert data and light curves of SVOM/GRM were downlinked to the ground through the VHF system with low latency. With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of a short single pulse with a duration of about 2 s and a weaker extended emission with a duration of about 40 s. The significance of extended emission observed by GRD03 is about 3.6 sigma from T0+2 to T0+42 s.
The initial pulse spectrum from T0-0.5 to T0+1.7 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.93 +/- 0.54 and the cutoff energy, parameterized as Epeak, is 214 +/- 59 keV. The event fluence (10-1000 keV) in this time interval is (1.05 +/- 0.19)E-06 erg/cm^2.
The extended emission spectrum from T0+1.7 to T0+42 s is best fit by a power law function. The power law index is -1.63 +/- 0.18. The event fluence (10-1000 keV) in this time interval is (1.76 +/- 0.31)E-07 erg/cm^2.
The time-integrate spectrum from T0-0.5 to T0+42 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.23 +/- 0.52 and the cutoff energy, parameterized as Epeak, is 455 +/- 335 keV. The event fluence (10-1000 keV) in this time interval is (2.13 +/- 0.48)E-07 erg/cm^2. According to the redshift z=2.702 (Izzo et al., GCN 38097), we estimate the burst isotropic equivalent radiated energy, parameterized as Eiso, is (1.76 +/- 0.76)E+53 erg (1-10000 keV).
The burst position (from Swift/BAT) was outside the SVOM/ECLAIRs field of view at trigger time.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.
The SVOM point of contact for this burst is: Chao Zheng (zhengchao97@ihep.ac.cn)