GRB 200914A
GCN Circular 28495
Subject
Konus-Wind observation of GRB 200914A
Date
2020-09-25T14:29:03Z (5 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@mail.ioffe.ru>
A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Lysenko, A. Ridnaia and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, hard-spectrum GRB 200914A
(Integral detection: Mereghetti et al., GCN 28419;
Fermi GBM observation: Dunwoody et al., GCN 28424;
AGILE detection: Ursi et al., GCN 28426)
triggered Konus-Wind at T0=46113.769 s UT (12:48:33.769).
The burst light curve shows a single pulse
which starts at ~T0-2.4 s and has a total duration of~38.0 s
The emission is seen up to ~2 MeV.
As observed by Konus-Wind, the burst
had a fluence of 4.26(-0.96,+1.08)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.306 s,
of 8.12(-2.44,+2.55)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.35(-0.34,+0.50),
the high energy photon index beta = -2.11(-0.70,+0.28),
the peak energy Ep = 461(-128,+201) keV,
chi2 = 93/97 dof.
The spectrum near the peak count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 1.6 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with�� alpha = -0.58(-0.16,+0.19),
and Ep = 935(-170,+228) keV (chi2 = 86/98 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.51 (chi2 = 86/97 dof).
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200914_T46113/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 28466
Subject
GRB 200914A: Swift-XRT further observations
Date
2020-09-21T17:19:16Z (5 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
P. D���Avanzo (INAF-OAB), T. Sbarrato (INAF-OAB), M. G. Bernardini (INAF-OAB),
A. Melandri (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:
Swift-XRT has performed further follow-up observations of the INTEGRAL-detected
burst GRB 200914A (Mereghetti et al. GCN Circ. 28419), collecting 5.7 ks of Photon
Counting (PC) mode data between T0+325 ks and T0+395 ks.
The only uncatalogued source in the field, Source 1 (Perri et al., GCN Circ. 28425),
is not detected anymore down to a 3sigma count rate limit of 2.1e-3 ct s^-1.
From a re-analysis of the first XRT observation, consisting in 1.2 ks of data collected between
T+9.0 ks and T+10.2 ks, we measure a count rate of 6.6e-3 (+3.3e-3, -2.5e-3) ct s^-1.
Although there is moderate evidence for fading between these two epochs, we cannot exclude
that the observed X-ray emission is coming from the bright IR source reported in Perri et al.
(GCN Circ. 28425), possibly unrelated to GRB 200914A.
This circular is an official product of the Swift-XRT team.
GCN Circular 28427
Subject
Fermi GRB 200914A: Global MASTER-Net observations report
Date
2020-09-15T21:19:52Z (5 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 200914A ( Fermi GBM team, GCN 28417) errorbox 38039 sec after notice time and 38210 sec after trigger time at 2020-09-14 23:25:20 UT, with upper limit up to 18.1 mag. Observations started at twilight. The observations began at zenith distance = 20 deg. The sun altitude is -13.4 deg.
The galactic latitude b = 2 deg., longitude l = 348 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1440752
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
38301 | 2020-09-14 23:25:20 | MASTER-OAFA | (16h 56m 29.13s , -36d 56m 30.6s) | C | 180 | 17.7 |
38481 | 2020-09-14 23:25:20 | MASTER-OAFA | (16h 56m 29.13s , -36d 56m 30.6s) | C | 540 | 18.0 | Coadd
39111 | 2020-09-14 23:25:20 | MASTER-OAFA | (16h 56m 29.13s , -36d 56m 30.6s) | C | 1800 | 18.1 | Coadd
38500 | 2020-09-14 23:28:40 | MASTER-OAFA | (16h 56m 34.98s , -36d 57m 34.1s) | C | 180 | 17.9 |
38700 | 2020-09-14 23:31:59 | MASTER-OAFA | (16h 56m 29.91s , -36d 58m 36.1s) | C | 180 | 17.9 |
38899 | 2020-09-14 23:35:19 | MASTER-OAFA | (16h 56m 34.57s , -36d 58m 21.9s) | C | 180 | 17.9 |
39079 | 2020-09-14 23:35:19 | MASTER-OAFA | (16h 56m 34.57s , -36d 58m 22.0s) | C | 540 | 18.1 | Coadd
39099 | 2020-09-14 23:38:39 | MASTER-OAFA | (16h 56m 32.35s , -36d 57m 01.7s) | C | 180 | 18.0 |
39299 | 2020-09-14 23:41:58 | MASTER-OAFA | (16h 56m 32.25s , -36d 58m 28.7s) | C | 180 | 17.9 |
39498 | 2020-09-14 23:45:18 | MASTER-OAFA | (16h 56m 35.42s , -36d 56m 54.9s) | C | 180 | 18.0 |
39678 | 2020-09-14 23:45:18 | MASTER-OAFA | (16h 56m 35.42s , -36d 56m 54.9s) | C | 540 | 18.1 | Coadd
39698 | 2020-09-14 23:48:37 | MASTER-OAFA | (16h 56m 29.19s , -36d 57m 42.1s) | C | 180 | 17.9 |
39897 | 2020-09-14 23:51:57 | MASTER-OAFA | (16h 56m 28.00s , -36d 56m 42.3s) | C | 180 | 17.9 |
40097 | 2020-09-14 23:55:16 | MASTER-OAFA | (16h 56m 35.44s , -36d 57m 43.0s) | C | 180 | 18.0 |
40277 | 2020-09-14 23:55:16 | MASTER-OAFA | (16h 56m 35.44s , -36d 57m 43.0s) | C | 540 | 18.1 | Coadd
40296 | 2020-09-14 23:58:36 | MASTER-OAFA | (16h 56m 27.73s , -36d 58m 42.5s) | C | 180 | 18.0 |
40495 | 2020-09-15 00:01:55 | MASTER-OAFA | (16h 56m 34.80s , -36d 58m 34.5s) | C | 180 | 18.0 |
40695 | 2020-09-15 00:05:15 | MASTER-OAFA | (16h 56m 31.42s , -36d 56m 51.9s) | C | 180 | 18.0 |
40875 | 2020-09-15 00:05:15 | MASTER-OAFA | (16h 56m 31.42s , -36d 56m 51.9s) | C | 540 | 18.1 | Coadd
40894 | 2020-09-15 00:08:34 | MASTER-OAFA | (16h 56m 31.25s , -36d 58m 30.5s) | C | 180 | 18.0 |
41094 | 2020-09-15 00:11:53 | MASTER-OAFA | (16h 56m 33.29s , -36d 56m 54.6s) | C | 180 | 18.0 |
41293 | 2020-09-15 00:15:13 | MASTER-OAFA | (16h 56m 27.73s , -36d 57m 44.2s) | C | 180 | 18.0 |
41473 | 2020-09-15 00:15:13 | MASTER-OAFA | (16h 56m 27.73s , -36d 57m 44.2s) | C | 540 | 18.1 | Coadd
41493 | 2020-09-15 00:18:32 | MASTER-OAFA | (16h 56m 26.87s , -36d 56m 44.4s) | C | 180 | 18.0 |
41692 | 2020-09-15 00:21:52 | MASTER-OAFA | (16h 56m 34.63s , -36d 57m 44.6s) | C | 180 | 18.0 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 28426
Subject
GRB 200914A: AGILE detection
Date
2020-09-15T14:09:50Z (5 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), F. Verrecchia, C. Pittori (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),
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:
The AGILE satellite detected the long GRB 200914A, reported by Fermi-GBM
(GCNs #28417, #28424), INTEGRAL (GCN #28419), and Swift-XRT (GCN #28425) at
T0 = 2020-09-14 12:48:30 (UT).
The event is clearly visible in the scientific ratemeters of the SuperAGILE
(SA; 18-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence
(AC; 50-200 keV) detectors. The light curves show a double peaked time
profile, lasting about 17 s. The burst released 1510 counts in the SA
detector (above a background rate of 80 Hz), 22600 counts in the MCAL
detector (above a background rate of 1280 Hz), and 61510 counts in the AC
detector (above a background rate of 3720 Hz). The emission detected by the
MCAL and AC detectors starts about ~9 s after the T0. The initial part of
the burst detected by AGILE triggered also a MCAL high time resolution data
acquisition. The AGILE ratemeter light curves can be found at:
http://www.agilescienceapp.it/notices/GRB200914A_AGILE_RMs.png .
Additional analysis of AGILE data is in progress.
GCN Circular 28425
Subject
GRB 200914A: Swift-XRT observations
Date
2020-09-15T09:57:10Z (5 years ago)
From
Paolo D'Avanzo at INAF - OAB <paolo.davanzo@inaf.it>
M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), J. D. Gropp
(PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 200914A (Mereghetti et al. GCN Circ. 28419), collecting 3.2
ks of Photon Counting (PC) mode data between T0+8.9 ks and T0+49.2 ks.
One uncatalogued X-ray source has been detected consistent with being
within 148 arcsec of the INTEGRAL position, it is below the RASS limit
and shows no definitive signs of fading. Therefore, at the present time
we cannot confirm this as the afterglow. Details of this source are
given below:
Source 1:
RA (J2000.0): 254.5202 = 16:58:4.84
Dec (J2000.0): -36.2782 = -36:16:41.6
Error: 6.5 arcsec (radius, 90% conf.)
Count-rate: (2.42 [+1.23, -0.93])e-3 ct s^-1
Distance: 53 arcsec from INTEGRAL position.
Flux: (10.0 [+5.0, -3.8])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Within the 90% error circle of Source 1 we note the presence of a
relatively bright IR source reported in the 2MASS and AllWISE
catalogues (2MASS 16580467-3616436 / AllWISE J165804.63-361643.5).
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021033.
This circular is an official product of the Swift-XRT team.
GCN Circular 28424
Subject
GRB 200914A: Fermi GBM observation
Date
2020-09-15T02:33:43Z (5 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
R. Dunwoody (UCD), J. Mangan (UCD) and C. Meegan (UAH) report on
behalf of the Fermi GBM Team:
"At 12:48:30.03 UT on 14 September 2020, the Fermi Gamma-Ray Burst
Monitor (GBM) triggered and located GRB 200914A (trigger 621780515 /
200914534) which was also detected by INTEGRAL (S. Mereghetti et al.,
GCN 28419). The GBM on-ground location is consistent with the INTEGRAL
position. The on-ground calculated location, using the GBM trigger
data, is provided in GCN 28417.
The angle from the Fermi LAT boresight at the GBM trigger time is 62 degrees.
The GBM light curve shows a long GRB with multiple features with a
duration (T90) of about 65 s (50-300 keV). The time-averaged spectrum
from T0 + 1.1 s to T0 + 24.6 s is best fit by a power law function
with an exponential high-energy cutoff. The power law index is -0.89
+/- 0.03 and the cutoff energy, parameterized as Epeak, is 1260 +/-
140 keV.
The event fluence (10-1000 keV) in this time interval is (9.80 +/-
0.71)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from
T0 + 1.95 s in the 10-1000 keV band is 7.9 +/- 0.2 ph/s/cm^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 28420
Subject
GRB 200914A: Swift ToO observations
Date
2020-09-14T14:36:13Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the INTEGRAL GRB 200914A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021033
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the INTEGRAL event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular 28419
Subject
GRB 200914A : A long GRB detected by INTEGRAL
Date
2020-09-14T13:32:19Z (5 years ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay),
C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany
and ISDC, Versoix)
and J.Borkowski (CAMK, Torun) report:
a gamma ray burst lasting about 70 s has been detected by IBAS in the
IBIS/ISGRI data at 12:48:30 UT of 2020 September 14.
The refined coordinates (J2000) are:
R.A.= 254.512 deg
DEC.= -36.2914 deg
with an uncertainty of 1.5 arcmin (90% c.l.).
The burst had a peak flux of about 2 counts/cm2/s (20-200 keV, 1-s
integration
time) and a fluence in the same energy range of about 3e-6 erg/cmq.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 28418
Subject
GRB 200914A: BALROG localization (Fermi Trigger 621780515 / GRB 200914534)
Date
2020-09-14T13:19:09Z (5 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
621780515 at 12:48:30 on 14 Sept. 2020 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) = 261.8+/-4.0 deg
Decl.(2000.0) = -35.8+/-2.0 deg
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB200914534/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB200914534/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB200914534/json
GCN Circular 28417
Subject
GRB 200914A: Fermi GBM Final Real-time Localization
Date
2020-09-14T12:59:03Z (5 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 12:48:30 UT on 14 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200914A (trigger 621780515.03441 / 200914534).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 256.4, Dec = -37.6 (J2000 degrees, equivalent to J2000 17h 05m, -37d 36'), with a statistical uncertainty of 1.8 degrees.
The angle from the Fermi LAT boresight is 62.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200914534/quicklook/glg_skymap_all_bn200914534.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/bn200914534/quicklook/glg_healpix_all_bn200914534.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200914534/quicklook/glg_lc_medres34_bn200914534.gif