GRB 231125A
GCN Circular 35190
Subject
GRB 231125A: AstroSat CZTI detection of a short burst
Date
2023-11-26T10:14:19Z (2 years ago)
From
Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>
Via
Web form
G. Waratkar (IITB), P. K. Navaneeth (IUCAA), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a short-duration GRB 231125A. We also inspected INTEGRAL/SPI-ACS data, and see a detection there.
The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-11-25 17:47:20.75 UTC. The measured peak count rate associated with the burst is 1641.9 (+219.7, -187.4) counts/s above the background in the combined data of three quadrants (out of four), with a total of 901 (+67, -66) counts. The local mean background count rate was 255.6 (+3.7, -6.9) counts/s. Using cumulative rates, we measure a T90 of 1.09 (+0.31, -0.23) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-11-25 17:47:20.72 UTC. The measured peak count rate is 1315.6 (+87.4, -93.6) counts/s above the background in the combined Veto data of all quadrants, with a total of 2706 (+219, -253) counts. The local mean background count rate was 1618.4 (+11.8, -11.9) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb
GCN Circular 35196
Subject
GRB 231125A (short): Glowbug gamma-ray detection
Date
2023-11-27T01:19:23Z (2 years ago)
From
C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>
Via
Web form
C.C. Cheung, M. Kerr, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 231125A, which was also detected by Astrosat/CZTI and INTEGRAL/SPI-ACS (GCN 35190).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-11-25 17:47:19.344 with a duration of 1.15 s and a total significance of about 194 sigma. The light curve comprises a single peak.
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=0.7 and a cutoff energy ("Epeak") of 296 keV. The modeled 10-10000 keV fluence is 6.1e-06 erg/cm^2.
The best-fit localization is RA, Decl. (J2000) = 109.7 deg, -30.6 deg with a radius of 2.6 deg (95% confidence), with a highly uncertain systematic uncertainty.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS. The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
Distribution Statement A: Approved for public release. Distribution is unlimited.
GCN Circular 35198
Subject
GRB 231125A: CALET Gamma-Ray Burst Monitor detection
Date
2023-11-27T12:41:07Z (2 years ago)
From
Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>
Via
Web form
Y. Akaike (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The GRB 231125A (AstroSat CZTI detection: Waratkar et al.,
GCN Circ 35190; Glowbug gamma-ray detection: Cheung et al.,
GCN Circ 35196) triggered the CALET Gamma-ray Burst Monitor
(CGBM) at 17:47:20.53 UTC on 25 November 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1384969551/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 single pulse that starts
at T-0.19 sec, peaks at T+0.41 sec, and ends at T+1.60 sec.
The T90 and T50 durations measured by the SGM data are
1.17 +/- 0.13 sec and 0.40 +/- 0.04 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1384969551/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.
GCN Circular 35199
Subject
GRB 231125A: GRBAlpha detection
Date
2023-11-27T13:02:50Z (2 years ago)
From
Jakub Ripa <ripa.jakub@gmail.com>
Via
Web form
J. Ripa, M. Dafcikova (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Szakszonova, J.-P. Breuer, 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.), yyT. 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 short-duration GRB 231125A (AstroSat/CZTI detection: GCN 35190; Glowbug detection: GCN 35196; INTEGRAL/SPI-ACS peak detection at 2023-11-25 ~17:47:21 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048).
The detection was confirmed at the peak time 2023-11-25 17:47:20.8 UTC. The T90 duration measured by GRBAlpha is 2 s and the overall significance during T90 reaches 12 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB231125A_GCN_GRBAlpha.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI 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, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.