GRB 211105A

A. Ursi, E. Menegoni (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and
INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M.
Cardillo, C. Casentini, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS),
F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, A. Di Piano, V. Fioretti,
F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN
Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team:

The AGILE satellite detected the long GRB 211105A at T0 = 2021-11-05
04:36:04 s (UTC).

The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV) and MiniCALorimeter (MCAL; 0.4-100 MeV)
detectors. The event lasted about 100 s and it released a total number of
14900 counts in the SA detector (above a background rate of 105 Hz) and
133500 counts in the MCAL detector (above a background rate of 1240 Hz).
The AGILE ratemeter light curves can be found at
http://www.agilescienceapp.it/notices/GRB211105A_AGILE_RM.png

Additional analysis of AGILE data is in progress.

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


During the commissioning phase, GECAM-B was triggered in-flight by a 
long bright burst, GRB 211105A, at 2021-11-05T04:35:20.200 UTC (denoted as T0)

Its alert data was promptly downlinked to the ground through the short
message service of BeiDou Navigation Satellite System (BDS). The time
latency of the first BeiDou message relative to the trigger time is about 1 minute.

According to the BDS alert data, this burst mainly consists of multiple
pulses with duration of about 100 s.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_16-25-24_89786120.png

GECAM-B localized this burst to the following position (J2000): 
Ra: 81.93 deg 
Dec: -57.38 deg
Err: 1.27 deg (1-sigma,statistical only)
The current systematic error of location is estimated to be several degrees 
which could be minimized by the ongoing calibration.

The GECAM preliminary location could be found here: 
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_skymap_bdm_89786120_V01.png

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).

James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), report:

Swift/BAT did not trigger on GRB 211105A (T0: 2021-11-05T04:35:20.2
UTC, GECAM-B GCN #31046
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 ).

The GECAM notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).

Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu,
arXiv:2111.01769
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 ), detects the burst with a sqrt(TS) of 16 in a 16.384
s analysis time bin. This is the maximum test duration of the search
pipeline. The full burst duration in the detector is greater than 60
s.

NITRATES prefers an origin for this burst coming from outside the
coded FOV, with DeltaLLHOut of -4.
An out of FOV origin is consistent with the GECAM localization.

See Section 9.1 and Figure 20 in the NITRATES paper for brief
descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and
DeltaLLHOut.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/

V. Lipunov, E.Gorbovskoy, K.Zhirkov, N.Tiurina, P.Balanutsa, A.Kuznetsov, 
O.Gress,G.Antipov, D. Vlasenko, V.Senik,V.Topolev, A.Chasovnikov, E.Minkina,
V.Grinshpun, D.Cheryasov (Lomonosov MSU,SAI,PhysicsDepartment),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
N.M. Budnev (Irkutsk State University, API),
C.Francile, R. Podesta, F. Podesta (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)

MASTER Global robotic net (MASTER-Net:http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L)
started inspect of GECAM GRB 211105A (Zhao et al. GCN 31046
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 , R.A.Dec(2000)=81.93,-57.38 +-1.27d;
Ttrigger=2021-11-05T 04:35:20.200 UT, Tnotice=2021-11-06 01:59:33UT)
by MASTER-OAFA (Argentina) at 2021-11-06 07:10:26UT (1 day 9306s after trigger time)
with upper limit up to  19.7 mag.

The observations began at zenith distance = 26 deg. The sun  altitude  is -27.4 deg.
The galactic latitude b = -34 deg., longitude l = 266 deg.

Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1777102

We obtained the following upper limits.

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
    95796 | 2021-11-06 07:10:26 |         MASTER-OAFA | (05h 24m 16.75s , -56d 44m 09.4s) |   C |   180 | 18.5 |
    95996 | 2021-11-06 07:13:46 |         MASTER-OAFA | (05h 24m 22.29s , -56d 44m 03.5s) |   C |   180 | 18.8 |
    96176 | 2021-11-06 07:13:46 |         MASTER-OAFA | (05h 24m 22.29s , -56d 44m 03.5s) |   C |   540 | 19.7 |  Coadd
    96196 | 2021-11-06 07:17:05 |         MASTER-OAFA | (05h 24m 18.69s , -56d 42m 43.7s) |   C |   180 | 18.8 |
    96395 | 2021-11-06 07:20:25 |         MASTER-OAFA | (05h 24m 18.52s , -56d 44m 01.5s) |   C |   180 | 18.8 |
    96595 | 2021-11-06 07:23:44 |         MASTER-OAFA | (05h 24m 21.21s , -56d 42m 41.0s) |   C |   180 | 18.9 |
    96775 | 2021-11-06 07:23:44 |         MASTER-OAFA | (05h 24m 21.21s , -56d 42m 41.0s) |   C |   540 | 19.7 |  Coadd
    96794 | 2021-11-06 07:27:04 |         MASTER-OAFA | (05h 24m 15.79s , -56d 43m 26.0s) |   C |   180 | 18.9 |
    96993 | 2021-11-06 07:30:23 |         MASTER-OAFA | (05h 24m 14.75s , -56d 42m 26.5s) |   C |   180 | 18.9 |
    97193 | 2021-11-06 07:33:43 |         MASTER-OAFA | (05h 24m 21.18s , -56d 43m 26.8s) |   C |   180 | 19.0 |
Filter C is a clear (unfiltred) band.

The observation and reduction will be continued
The message may be cited.