GRB 210324C
GCN Circular 29734
Subject
GRB 210324C: AstroSat CZTI detection
Date
2021-03-30T05:19:42Z (6 years ago)
From
Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>
P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), S. Gupta
(IUCAA), V. Bhalerao (IITB), D. Bhattacharya (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, 2020,
arxiv:2011.07067) showed detection of a long GRB 210324C, which was also
detected by Fermi-GBM (GCN #29718), and Konus-Wind (GCN #29728).
The source was clearly detected in the 20-200 keV energy range. The light
curve showed multiple peaks of emission with the strongest peak at
2021-03-24 20:00:36.50 UT. The measured peak count rate associated with the
burst is 214 (+47, -35) cts/s above the background in the combined data of
four quadrants, with a total 4856 (+784, -875) cts. The local mean
background count rate was 604 (+3, -3) cts/s. Using cumulative rates, we
measure a T90 of 63 (+14, -11) s.
CZTI GRB detections are reported regularly on the payload site at
http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led
consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and
PRL. The Indian Space Research Organisation funded, managed and facilitated
the project.
GCN Circular 29728
Subject
Konus-Wind detection of GRB 210324C
Date
2021-03-25T18:42:58Z (6 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, S. Golenetskii, A.Lysenko, A. Ridnaia,
D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 210324C (IPN triangulation: Hurley et al., GCN 29727)
triggered Konus-Wind (KW) at T0=72000.034 s UT (20:00:00.034).
The burst light curve shows a multi-peaked structure with the total
duration of ~75 s.
The emission is seen up to ~10 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB210324_T72000/
As observed by Konus-Wind, the burst had
a fluence of (7.0 �� 0.6)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0+34.112,
of (3.4 �� 0.4)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+65.024 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.51 (-0.10,+0.11),
the high energy photon index beta = -2.69 (-0.28,+0.18),
the peak energy Ep = 190 (-11,+12) keV,
chi2 = 97/97 dof.
The spectrum near the peak count rate (measured from T0+33.024
to T0+40.448 s) is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.56 (-0.15,+0.17),
the high energy photon index beta = -2.64 (-0.53,+0.24),
the peak energy Ep = 211 (-21,+26) keV,
chi2 = 108/97 dof.
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
GCN Circular 29727
Subject
IPN triangulation of GRB 210324C
Date
2021-03-25T18:28:37Z (6 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
K. Hurley, on behalf of the IPN,
I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak,
and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
A. Ridnaia, S. Golenetskii, D. Frederiks, D. Svinkin,
A. Lysenko, and T. Cline on behalf of the Konus-Wind team,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:
The long-duration GRB 210324C
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 29718;
BALROG localization: Kunzweileret et al., GCN Circ. 29719)
has been detected by Fermi (GBM trigger 638308803),
INTEGRAL (SPI-ACS), Konus-Wind, and Mars-Odyssey (HEND),
so far, at about 71998 s UT (19:59:58).
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
35.111 (02h 20m 27s) -48.606 (-48d 36' 21")
Corners:
43.843 (02h 55m 22s) -51.173 (-51d 10' 22")
43.444 (02h 53m 46s) -51.998 (-51d 59' 54")
27.400 (01h 49m 36s) -45.327 (-45d 19' 38")
27.969 (01h 51m 53s) -44.554 (-44d 33' 15")
---------------------------------------------
The error box area is 10.7 sq. deg, and its maximum
dimension is 12.7 deg (the minimum one is 51 arcmin).
The Sun distance was 51 deg.
This box may be improved.
The IPN localization is consistent with, but reduces the area of, the
Fermi RoboBA and BALROG localizations (GCN Circ. 29718 and 29719).
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB210324_T72000/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 29723
Subject
Fermi GRB 210324C: Global MASTER-Net observations report
Date
2021-03-24T22:30:17Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov, D. Cheryasov
(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. Gres, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko
(Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 210324C ( Fermi GBM team, GCN 29718) errorbox 2759 sec after notice time and 2786 sec after trigger time at 2021-03-24 20:46:24 UT, with upper limit up to 17.1 mag. The observations began at zenith distance = 81 deg. The sun altitude is -48.8 deg.
The galactic latitude b = -63 deg., longitude l = 263 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1576010
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
2876 | 2021-03-24 20:46:24 | MASTER-SAAO | (02h 45m 04.74s , -47d 04m 20.4s) | C | 180 | 17.1 |
3076 | 2021-03-24 20:49:44 | MASTER-SAAO | (02h 44m 59.67s , -47d 05m 16.2s) | C | 180 | 16.7 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 29719
Subject
GRB 210324C: BALROG localization (Fermi Trigger 638308803 / GRB 210324833)
Date
2021-03-24T20:21:57Z (6 years ago)
From
Jochen Greiner at MPE,Garching <jcg@mpe.mpg.de>
F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
638308803 at 19:59:58 on 24 March 2021 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 43.2+/-0.6 deg
Decl.(2000.0) = -48.1+/-0.5 deg
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB210324833/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB210324833/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB210324833/json
GCN Circular 29718
Subject
GRB 210324C: Fermi GBM Final Real-time Localization
Date
2021-03-24T20:10:22Z (6 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB
At 19:59:58 UT on 24 Mar 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210324C (trigger 638308803.321686 / 210324833).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 37.6, Dec = -46.0 (J2000 degrees, equivalent to J2000 02h 30m, -46d 00'), with a statistical uncertainty of 1.8 degrees.
The angle from the Fermi LAT boresight is 37.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_skymap_all_bn210324833.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_healpix_all_bn210324833.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif