GRB 230913A
GCN Circular 34680
Subject
GRB 230913A: Fermi GBM Final Real-time Localization
Date
2023-09-13T08:06:34Z (2 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 07:56:12 UT on 13 Sep 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230913A (trigger 716284577.16364 / 230913331).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 287.6, Dec = 78.9 (J2000 degrees, equivalent to J2000 19h 10m, 78d 54'), with a statistical uncertainty of 6.5 degrees.
The angle from the Fermi LAT boresight is 41.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230913331/quicklook/glg_skymap_all_bn230913331.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230913331/quicklook/glg_healpix_all_bn230913331.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230913331/quicklook/glg_lc_medres34_bn230913331.gif
GCN Circular 34682
Subject
Fermi GRB 230913A: Global MASTER-Net observations report
Date
2023-09-13T11:30:45Z (2 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
legacy email
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)
MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 230913A ( Fermi GBM team, GCN 34680) errorbox 12289 sec after notice time and 12299 sec after trigger time at 2023-09-13 11:21:12 UT, with upper limit up to 18.5 mag. Observations started at twilight. The observations began at zenith distance = 27 deg. The sun altitude is -14.7 deg.
The galactic latitude b = 26 deg., longitude l = 111 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2269810
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
12330 | 2023-09-13 11:21:12 | MASTER-Amur | (19h 14m 13.35s , +77d 14m 05.4s) | C | 60 | 18.5 |
12411 | 2023-09-13 11:22:33 | MASTER-Amur | (19h 32m 21.13s , +76d 57m 30.6s) | C | 60 | 18.4 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 34683
Subject
GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
Date
2023-09-13T13:55:53Z (2 years ago)
From
Samuele Ronchini at PSU <sjs8171@psu.edu>
Via
Web form
Samuele Ronchini (PSU), Jamie A. Kennea (PSU), James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Tyler Parsotan (NASA GSFC) report:
Swift/BAT did not localize GRB 230913A onboard (T0: 2023-09-13T07:56:12.16 UTC, Fermi/GBM GCN 34680, CALET trigger 1378626813).
The Fermi and CALET notices, 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 2022, ApJ, 941, 169), detects the burst in a 8.192 s analysis time bin with a sqrt(TS) of 19.7.
An arcminute localization is found with DeltaLLHOut of 64.99 and a DeltaLLHPeak of 60.07.
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
The BAT position is
RA, Dec = 267.349, +74.484 deg (J2000) which is
RA (J2000) 17h 49m 23.8s
Dec (J2000) 74d 29m 2.4s
with an estimated uncertainty of 5 arcmin radius.
No XRT and UVOT follow-up can be done due to observational constraints.
We strongly encourage follow-up from other telescopes.
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/
GCN Circular 34689
Subject
GRB 230913A: Fermi GBM Observation
Date
2023-09-13T21:26:08Z (2 years ago)
From
Sarah Dalessi at UAH <sd0104@uah.edu>
Via
Web form
S. Dalessi (UAH), R. Hamburg (CNRS/IJCLab), and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 07:56:12.16 UT on 13 September 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230913A (trigger 716284577/230913331).
which was also detected by Swift/BAT GUANO (S. Ronchini et al. 2023, GCN 34683).
The Fermi GBM Final Real-time Localization was reported in GCN 34680.
The angle from the Fermi LAT boresight is 41 degrees.
The GBM light curve single peak with a duration (T90)
of about 12 s (50-300 keV). The time-averaged spectrum
from T0-1.0 to T0+9.2 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.1 +/- 0.2 and the cutoff energy,
parameterized as Epeak, is 160 +/- 10 keV.
The event fluence (10-1000 keV) in this time interval is
(3.1 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3 s in the 10-1000 keV band is 2.1 +/- 0.2 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 130 +/- 20 keV, alpha = 0.3 +/- 0.4 and beta = -2.3 +/- 0.2.
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/"
GCN Circular 34696
Subject
GRB 230913A: Glowbug gamma-ray detection
Date
2023-09-14T21:40:12Z (2 years ago)
From
matthew.kerr@gmail.com
Via
Web form
M. Kerr, C.C. Cheung, 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 230913A, which was also detected by Fermi/GBM, CALET, and Swift/BAT-GUANO (GCN 34680, 34683)
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-09-13 07:56:06.008 with a duration of 12.3 s and a total significance of about 22.2 sigma.
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=2.0 and a cutoff energy ("Epeak") of 152 keV. The modeled 10-10000 keV fluence is 7.7e-07 erg/cm^2.
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 34700
Subject
GRB 230913A: CALET Gamma-Ray Burst Monitor detection
Date
2023-09-15T03:21:21Z (2 years ago)
From
Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>
Via
Web form
M. L. Cherry (LSU), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The long GRB 230913A (Fermi GBM Final Real-time Localization:
Fermi GBM team, GCN Circ. 34680; Swift/BAT-GUANO arcminute
localization, Ronchini et al., GCN Circ. 34683; Fermi GBM Observation:
Dalessi et al., GCN Circ. 34689; Glowbug gamma-ray detection: Kerr et al.,
GCN Circ. 34696) triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 07:56:11.95 UTC on 13 September 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1378626813/index.html).
The burst signal was seen by all CGBM detectors.
The burst light curve shows a single pulse that starts
at T+0.9 sec, peaks at T+1.5 sec, and ends at T+4.4 sec.
The T90 and T50 durations measured by the SGM data are 3.1 +/- 0.3 sec
and 1.9 +/- 0.4 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1378626813/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.