GRB 240603A
GCN Circular 36602
Subject
GRB 240603A: GECAM detection of a short burst
Date
2024-06-03T04:36:25Z (a year ago)
From
Chenwei Wang at IHEP <cwwang@ihep.ac.cn>
Via
Web form
Chen-Wei Wang, Shao-Lin Xiong report on behalf of the GECAM team:
GECAM-B was triggered in-flight by a weak short burst, GRB 240603A, at 2024-06-03T02:27:33.950 UTC (T0), which was also detected by INTEGRAL/SPI-ACS (trigger #10729).
The GECAM-B in-flight location (J2000) is:
Ra: 3.5 deg
Dec: -18.5 deg
Err: 5.9 deg (1-sigma, statistical only)
According to the realtime alert data of GECAM-B, this burst mainly consists of a spike and a tail with a total duration of about 1 s. The time-averaged spectrum from T0-0.5 s to T0 could be adequately fit by a power law with high energy exponential cutoff function with a fluence of about 1.21E-6 erg/cm^2 in 20-1000 keV.
We note that these results are very preliminary. Refined analysis will be reported later.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).
GCN Circular 36608
Subject
GRB 240603A: Fermi GBM Final Localization
Date
2024-06-03T17:36:14Z (a year ago)
From
sumanbala2210@gmail.com
Via
Web form
The Fermi GBM team reports the detection of a likely SHORT GRB
"At 02:27:33.48 UT on 03 June 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240603A (trigger 739074458/240603102).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 324.16, Dec = -18.92 (J2000 degrees, equivalent to J2000 21h 36m, -18d 55'),
with a statistical uncertainty of 3.06 degrees.
The angle from the Fermi LAT boresight is 86.00 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240603102/quicklook/glg_skymap_all_bn240603102.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240603102/quicklook/glg_healpix_all_bn240603102.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240603102/quicklook/glg_lc_medres34_bn240603102.gif"
GCN Circular 36618
Subject
IPN triangulation of GRB 240603A
Date
2024-06-05T12:19:02Z (a year ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
Via
Web form
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,
D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,
A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:
The short-duration GRB 240603A
(GECAM-B detection: Wang et al., GCN 36602;
Fermi-GBM detection: The Fermi GBM team, GCN 36608)
was detected by Fermi (GBM trigger 739074458), Konus-Wind
INTEGRAL (SPI-ACS), GECAM-B, and Mars-Odyssey (HEND)
at about 8853 s UT (02:27:33).
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
328.634 (21h 54m 32s) -24.049 (-24d 02' 58")
Corners:
329.538 (21h 58m 09s) -25.739 (-25d 44' 21")
329.570 (21h 58m 17s) -25.919 (-25d 55' 10")
327.632 (21h 50m 32s) -22.008 (-22d 00' 28")
327.575 (21h 50m 18s) -21.746 (-21d 44' 44")
---------------------------------------------
The error box area is 821 sq. arcmin, and its maximum
dimension is 4.56 deg (the minimum one is 3.2 arcmin).
The Sun distance was 110 deg.
The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final localization.
This localization may be improved.
A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240603_T08857/IPN
The HEALPix triangulation map is the multi-order HEALPix in units of probability density.
The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.
GCN Circular 36627
Subject
Konus-Wind detection of GRB 240603A
Date
2024-06-06T12:47:29Z (a year ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Via
Web form
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The short-duration GRB 240603A
(GECAM-B detection: Wang & Xiong, GCN 36602;
Fermi-GBM detection: The Fermi GBM team, GCN 36608;
IPN triangulation: Kozyrev et al., GCN 36618)
triggered Konus-Wind at T0=8857.191 s UT (02:27:37.191).
The burst light curve shows a single pulse,
which starts at ~T0-0.3 s and has a total duration of ~1.1 s.
The emission is seen up to ~4 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240603_T08857/
As observed by Konus-Wind, the burst
had a fluence of 3.81(-0.02,+0.84)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.504 s,
of 8.34(-2.03,+2.74)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
Since a significant fraction of the burst counts
was detected before the trigger, the spectral analysis
was performed using the KW 3-channel light curve data.
Modelling the KW 3-channel time-integrated spectrum
(measured from T0-0.260 s to T0+0.784 s)
by a power law with exponential cutoff (CPL) model,
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -1.08(-0.68,+1.42) and Ep = 592(-82,+92) keV.
All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.
GCN Circular 36668
Subject
GRB 240603A: VZLUSAT-2 detection
Date
2024-06-14T22:17:33Z (a year ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration.
The short-duration GRB 240603A (Fermi/GBM detection: GCN 36608; Konus/Wind detection: GCN 36627; GECAM-B detection: GCN 36602; INTEGRAL/SPI-ACS peak detection at 2024-06-03 ~02:27:33 UT) was detected by the GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).
The data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2024-06-03 02:27:32 UTC. The T90 duration is 1 s (2 s) and the significance during T90 reaches 5.9 sigma (6.9 sigma) for detector unit no. 0 (no. 1).
The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB240603A_GCN_VZLUSAT2.pdf
All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.