GRB 200311A
GCN Circular 27398
Subject
Konus-Wind observation of GRB 200311A
Date
2020-03-17T11:51:37Z (6 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 200311A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27363;
AGILE-MCAL detection: Ursi et al., GCN Circ. 27365;
AstroSat-CZTI detection: Gupta et al., GCN Circ. 27371;
IPN triangulation: Svinkin et al., GCN Circ. 27381)
triggered Konus-Wind at T0=54974.737 s UT (15:16:14.737).
The burst light curve shows a multipeaked structure
which starts at ~T0-0.8 s and has a total duration of ~65.2 s.
The emission is seen up to ~8 MeV.
As observed by Konus-Wind, the burst
had a fluence of 8.84(-0.76,+0.89)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.792 s,
of 1.56(-0.28,+0.28)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+64.512 s)
is best fit in the 20 keV - 8 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.93(-0.07,+0.08)
and Ep = 854(-112,+142) keV (chi2 = 113/81 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.1
(chi2 = 112/80 dof).
The spectrum near the maximum count rate
(measured from T0+0.256 to T0+7.168 s)
is best fit in the 20 keV - 8 MeV range
by a power law with exponential cutoff model
with alpha = -0.57(-0.08,+0.09)
and Ep = 957(-98,+114) keV (chi2 = 88/80 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.2
(chi2 = 86/79 dof).
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200311_T54974/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 27381
Subject
IPN triangulation of GRB 200311A
Date
2020-03-13T12:49:49Z (6 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
IPN triangulation of GRB 200311A
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,
K. Hurley, on behalf of the IPN,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team, and
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:
The long-duration GRB 200311A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27363;
AGILE-MCAL detection: Ursi et al., GCN Circ. 27365;
AstroSat-CZTI detection: Gupta et al., GCN Circ. 27371)
was detected by Fermi (GBM trigger 605632577), Konus-Wind,
INTEGRAL (SPI-ACS), AGILE-MCAL, and AstroSat-CZTI
at about 54973 s UT (15:16:13).
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
209.245 (13h 56m 59s) -50.054 (-50d 03' 15")
Corners:
206.898 (13h 47m 35s) -52.496 (-52d 29' 46")
211.898 (14h 07m 35s) -47.578 (-47d 34' 42")
211.296 (14h 05m 11s) -47.578 (-47d 34' 39")
206.215 (13h 44m 52s) -52.473 (-52d 28' 23")
---------------------------------------------
The error box area is 2.0 sq. deg, and its maximum
dimension is 6.1 deg (the minimum one is 21 arcmin).
The Sun distance was 117 deg.
This box may be improved.
The IPN localization is consistent with, but reduces the area of, the
Fermi-GBM final position (GCN Circ. 27363).
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200311_T54974/IPN
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 27371
Subject
GRB 200311A: AstroSat CZTI detection
Date
2020-03-12T08:29:18Z (6 years ago)
From
Soumya Gupta at IUCAA/ASTROSAT <soumya@iucaa>
S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed the detection of a GRB 200311A, which was also detected by Fermi GBM (GCN #27363), AGILE/MCAL (Ursi A. et al., GCN #27365) and Global MASTER-Net (Lipunov V. et al., GCN #27370).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-03-11 15:16:13.516 UT. The measured peak count rate associated with the burst is 958 +/- 38.4 cts/s above the background in the combined data of four quadrants, with a total of 10660 +/- 42.9 cts. The local mean background count rate was 532 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 30.5 +/- 0.03 s. In preliminary analysis, we find that 1186 Compton events are associated with this event.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
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 27365
Subject
GRB 200311A: AGILE/MCAL and scientific ratemeters observations
Date
2020-03-11T18:54:28Z (6 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), F. Longo (Univ. Trieste and INFN Trieste), M. Pilia
(INAF/OA-Cagliari), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C.
Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani
(INAF/IASF-Mi), report on behalf of the AGILE Team:
The AGILE satellite detected the long burst GRB 200311A reported by
Fermi/GBM (GCN #27363), that also triggered the automatic AGILE
Mini-CALorimeter (MCAL) GRB alert Notice (ID 511024575), published at:
https://gcn.gsfc.nasa.gov/agile_mcal.html.
The event is visible in the scientific ratemeters (RMs) of the
Anti-Coincidence (AC, 50-200 keV) and MCAL (0.4-100 MeV) detectors. The
burst light curve shows a multi-peaked profile, lasting ~25 s and releasing
~33000 counts in the MCAL RMs. The ratemeters light curves can be found at
http://www.agilescienceapp.it/notices/GRB_066883_511024575.756958_RM.png.
The event also triggered an MCAL data acquisition at T0 = 2020-03-11
15:16:15.75 +/- 0.01 s (UTC), lasting ~10 s and releasing a total number of
~7550 counts in the detector, above a background rate of ~700 Hz. The MCAL
light curve can be found at:
http://www.agilescienceapp.it/notices/GRB_066883_511024575.756958.png.
The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress.
GCN Circular 27363
Subject
GRB 200311A: Fermi GBM Final Real-time Localization
Date
2020-03-11T15:24:19Z (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 15:16:12 UT on 11 Mar 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200311A (trigger 605632577.928052 / 200311636).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 204.0, Dec = -49.7 (J2000 degrees, equivalent to J2000 13h 35m, -49d 42'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 122.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200311636/quicklook/glg_skymap_all_bn200311636.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200311636/quicklook/glg_healpix_all_bn200311636.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200311636/quicklook/glg_lc_medres34_bn200311636.gif