GRB 210410A
GCN Circular 29817
Subject
GRB 210410A: AstroSat CZTI detection
Date
2021-04-15T14:44:22Z (5 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 210410A, which was also
detected by Fermi-GBM (GCN #29777, #29788), Swift-XRT (GCN #29778, #29790),
Fermi-LAT (GCN #29781), Swift-BAT (GCN #29793), Konus-Wind (GCN #29797) and
AGILE-MCAL (GCN #29798).
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
2021-04-10 00:53:16.50 UT. Quadrant D was noisy, and we exclude it from
further analysis. The measured peak count rate associated with the burst is
225 (+45, -16) cts/s above the background in the combined data of four
quadrants, with a total of 1808 (+239, -299) cts. The local mean background
count rate was 373 (+2, -2) cts/s. Using cumulative rates, we measure a
T90 of 20 (+6, -7) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in
the 100-500 keV energy range. The light curve showed multiple peaks of
emission with the strongest peak at 2021-04-10 00:53:15.867 UT. The
measured peak count rate is 1149 (+91, -57) cts/s above the background in
the combined Veto data of four quadrants, with a total of 8483 (+515, -574)
cts. The local mean background count rate was 1580 (+4, -4) cts/s. We
measure a T90 of 18 (+6, -4) s from the cumulative Veto light curve.
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 29816
Subject
GRB 210410A: A twin of short GRB 090510 with complementary observations
Date
2021-04-15T08:43:33Z (5 years ago)
From
Remo Rufinni at ICRA <ruffini@icra.it>
Y. Aimuratov, C.L. Bianco, L. Li, R. Moradi, F. Rastegar Nia, J.A.
Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue on behalf of the
ICRANet team, report:
GRB 210410A has been announced as a likely long GRB (Fermi GBM Team
2021, GCN 29777), it has been also observed by Swift-XRT (A. Melandri
et al 2021, GCN 29778, and A. D���Ai et al, 2021, GCN 29790), by
Fermi-LAT (M. Arimoto et al 2021, GCN 29781), by AGILE (A. Ursi et al.
2021, GCN 29782), by Swift BAT (A. Y. Lien et al, 2021 GCN 29793) as
well as by Konus-Wind (A. Ridnaia et al 2021, GCN 29797). The
Fermi-GBM has determined T90=48 s in 50-300 keV (J. Wood et al 2021,
GCN 29788). A possible detection of the host galaxy at redshift z<3.6
was indicated by Butler et al 2021 (GCN 29784).
We here propose that GRB 210410A is a twin and covers the
complementary observation to the short GRB 090510, with T90=0.3 s. (R.
Ruffini et al 2016 ApJ 831 178).
We infer that GRB 210410A is a short GRB originating from a black hole
formation in view of its observed GeV emission (M. Arimoto et al
GCN29781) that and no supernova will be detected. We evidence for the
first time an angle dependence of the emission of short GRB: in the
polar observation for GRB 090510, with T90=0.3 s and in the equatorial
observation for GRB 210410A, with T90=48 s.
The spectroscopic determination of the redshift of the host galaxy is
essential for the determination of the GeV luminosity and consequently
the BH mass (R. Ruffini et al 2019 ApJ 886 82). We indicate the
relevance of the redshift determinations in the two enclosed figures.
"http://www.icranet.org/documents/GRB210410A-z=0.6-and-GRB090510-z=0.903.pdf"
"http://www.icranet.org/documents/GRB210410A-z=3.6-and-GRB090510-z=0.903.pdf"
GCN Circular 29812
Subject
GRB 210410A: Swift/UVOT Upper Limits (revision)
Date
2021-04-13T12:29:44Z (5 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Paul Kuin (MSSL/UCL) reports on behalf of the Swift/UVOT team:
In our previous report (Kuin & Melandri, GCN Circ 29787) we made
an error computing T0, which affected our T_start and T_stop times.
Below are the corrected values.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) mag 3-sigma UL
v 1070 1095 19 >17.0
b 4967 5055 85 >19.7
u 4763 4960 197 >19.9
w1 4556 4755 197 >19.3
m2 4349 4548 197 >19.4
w2 1059 1071 12 >17.0
GCN Circular 29805
Subject
GRB 210410A: MITSuME Akeno optical upper limits
Date
2021-04-12T10:29:30Z (5 years ago)
From
Katsuhiro L. Murata at Nagoya U <murata@u.phys.nagoya-u.ac.jp>
K. L. Murata, R. Hosokawa, M. Niwano, N. Ito, H. Takamatsu, Y. Yatsu, and
N.Kawai (TokyoTech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 210410A (The Fermi GBM team et al. GCN
Circular #29777, A. Melandri et al. GCN Circular #29778, V. Lipunov et al.
GCN Circular #29779, M. Jelinek et al. GCN Circular #29780, M. Arimoto et
al. GCN Circular #29781, A. Ursi et al. GCN Circular #29782, Nat Butler et
al. GCN Circular #29784, Nat Butler et al. GCN Circular #29786, Paul Kuin
et al. GCN Circular #29787, J. Wood et al. GCN Circular #29788, A. D'Ai et
al. GCN Circular #29790, A. Y. Lien et al. GCN Circular #29793, A. Ridnaia
et al. GCN Circular #29797, A. Ursi et al. GCN Circular #29798) with the
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50
cm telescope of Akeno Observatory, Yamanashi, Japan. The observation with a
series of 60 sec exposures started at 2021-04-10 13:35 (9.7 hours after the
Fermi/GBM trigger). We stacked the images with good conditions. We did not
detect the optical afterglow reported previously (Jelinek et al. GCN
Circular #29780, Butler et al. GCN Circular #29784) in all three bands. We
obtained the 5-sigma limits of the stacked images as follows.
T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
10.0 14:00:15 1740 g'>19.3, Rc>19.6, Ic>19.0
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used the PS1 catalog for flux calibration.The magnitudes are expressed
in the AB system. The images were processed in real-time through the
MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1,
Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN Circular 29798
Subject
GRB 210410A: AGILE/MCAL analysis
Date
2021-04-11T19:51:25Z (5 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), F.
Verrecchia, C. Pittori (SSDC, and INAF/OAR), A. Argan, M. Cardillo, C.
Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, A. Di Piano, V. Fioretti, F. Fuschino, N.
Parmiggiani (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen
University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F.
Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report
on behalf of the AGILE Team:
We carried out further analysis of the AGILE/MCAL data of GRB 210410A (GCNs
#29777, #29778, #29779, #29780, #29781, #29782, #29786, #29787, #29788,
#29790, #29793