GRB 221029A

J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk 
U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly 
Observatory), M. Dafcikova, F. Munz, N. Husarikova, J.-P. Breuer, M. 
Topinka, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,�� A. Povalac (Brno 
U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. 
Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky 
(Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos 
U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida 
(ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto 
(Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. 
Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), 
K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),�� T. Mizuno 
(Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. 
Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama 
(Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) 
-- the GRBAlpha collaboration.

The long-duration GRB 221029A (Fermi-GBM detection trigger 
688698332/221029045; INTEGRAL/SPI-ACS detection peak at about 2022-10-29 
01:05:28) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 
2020).

The 9.8 sigma detection was confirmed at the peak time 2022-10-29 
01:05:27.8 UTC. The GRB has the T90 duration of 36 s.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB221029A_GCN_GRBAlpha.pdf

GRBAlpha, launched on 2021 March 22, is a demonstration mission for a 
future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its 
detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by 
a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To 
increase the duty cycle and the downlink rate, we are continuously 
upgrading the on-board data acquisition software stack. The ground 
segment is also supported by the radio amateur community and it takes 
advantage of the SatNOGS network for increased data downlink volume.

James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (GSFC/UMBC) report:

Swift/BAT did not localize GRB 221029A onboard (T0:
2022-10-29T01:05:27 UTC, GECAM trig 49, Fermi/GBM trig 688698332,
GRBAlpha GCN 32890
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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 51.6 in a
2.048 s analysis time bin.

NITRATES results indicate a burst coming from outside the FOV, with
DeltaLLHOut of -60.
The NITRATES best fit sky location is consistent with the Fermi/GBM
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/

The Fermi GBM team reports the detection of a likely Long GRB.

"At 01:05:27.31 UT on 29 October 2022, the Fermi Gamma-Ray Burst
Monitor (GBM) triggered and located GRB221029A (trigger 688698332 /
221029045).

The on-ground calculated location, using the GBM trigger data, is RA =
53.3, DEC = -44.9 (J2000 degrees, equivalent to 3h 33m, -44d 54'),
with a statistical uncertainty of 1 degrees (radius, 1-sigma
containment, statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90%
of GRBs having a 3.7 deg error and a small tail suffering a larger
than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32]
).

The angle from the Fermi LAT boresight at the GBM trigger time is 72 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221029045/quicklook/glg_skymap_all_bn221029045.png

The HEALPix FITS file, including the estimated localization
systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221029045/quicklook/glg_healpix_all_bn221029045.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221029045/quicklook/glg_lc_medres34_bn221029045.gif

J. Mangan (UCD), R. Dunwoody (UCD) and C. Meegan (UAH), report on behalf of
the Fermi GBM Team:

At 01:05:27.31 UT on 29 October 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 221029A (trigger 688698332 / 21029045). The
Fermi GBM Final Real-time Localization is reported in GCN 32900
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 .

The GBM light curve consists of three emission episodes
with a duration (T90) of about 27.7 s (50-300 keV).
The time-averaged spectrum from T0+0.003 s to T0+28.416 s is
best fit by a Band function with Epeak = 130.7 +/- 6.3 keV,
alpha = -1.12 +/- 0.03, and beta = -2.15 +/- 0.04

The event fluence (10-1000 keV) in this time interval is
(2.69 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.32 s in the 10-1000 keV band
is 35.5 +/- 0.5 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM
Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/

S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 221029A (Detection by GRBAlpha: Ripa et al., GCN Circ. 32890
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 ;
Swift/BAT-GUANO detection: DeLaunay et al., GCN Circ. 32891
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 ;
Fermi GBM Final Localization: Fermi GBM team, GCN Circ. 32900
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 ;
Fermi GBM observation: Mangan et al., GCN Circ. 32903
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 ) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 01:05:26.60 UTC on 29 October 2022
(http://cgbm.calet.jp/cgbm_trigger/flight/1351040741/index.html).
The burst signal was seen by all CGBM detectors.
No real-time CGBM GCN notice was distributed about this trigger because
the real-time communication from the ISS was off (loss of signal).

The burst light curve shows a multi-peaked structure that starts
at T+0.2 sec, peaks at T+1.6 sec, and ends at T+32.4 sec.
The T90 and T50 durations measured by the SGM data are 27.6 +/- 0.8 sec
and 12.7 +/- 1.4 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1351040741/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.