GCN Circular 31150

Y. Q. Zhang, S. L. Xiong, C. Cai, S. Xiao, P. Zhang, 
C. Y. Li, S. L. Xie, X. Y. Zhao, Y. Huang, X. Y. Song,
J. C. Liu,  Y. Zhao, Z. W. Guo, C. Zheng, W. C. Xue, C. W. Wang, 
Q. B. Yi, B. X. Zhang,  W. X. Peng, R. Qiao, D. Y. Guo, X. B. Li, 
X. Ma, L. M. Song, P. Wang, J. Wang, Z. Zhang, S. J. Zheng, W. Chen, 
J. J. He, G. Y. Zhao, Y. Q. Du, H. Wu, J. Liang, Q. Luo, X. L. Zhang, 
H. M. Zhang, Z. H. An, M. Gao, K. Gong, B. Li, C. Li, J. H. Li, 
X. Q. Li, Y. G. Li, X. H. Liang, X. J. Liu, Y. Q. Liu, X. L. Sun, 
Y. L. Tuo, J. Z. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, 
C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang,
X. Zhou, F. J. Lu, S. N. Zhang (IHEP)
report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered by a short burst, 
GRB 211106A, at 2021-11-06T04:37:31.250 UTC (denoted as T0), which was 
also observed by Swift/BAT-GUANO (GCN #31049), Fermi/GBM Sub-Threshold
(GCN #31055), Konus-Wind (GCN #31054), INTEGRAL/SPI-ACS (TrigID #9504)
and IPN (GCN #31078).

According to the GECAM-B light curves, this burst mainly consists of 
two pulses with duration of about 2 s.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_89872651.PNG

GECAM location is consistent with the Swift/BAT position within the error.

The time-integrated spectrum (measured from T0-0.25 s to T0+1.85 s) 
is best fit by the power law model (in the 20 keV - 5 MeV range):
A(E) ~ k * E^(-alpha) with alpha = 1.32 (-0.13, 0.15).
The burst had a fluence of 6.35 (3.72, 7.05)x10^-7 erg/cm^2 (20 - 200 keV)
during the time interval metioned above. 
All parameters in parenthesis are for 90% confidence level.

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).