GRB 201103B
GCN Circular 28872
Subject
Konus-Wind observation of GRB 201103B
Date
2020-11-09T15:28:16Z (5 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 201103B
(AGILE detection: Ursi et al., GCN Circ. 28831;
ZTF afterglow discovery: Coughlin et al., GCN Circ. 28841;
IPN triangulation: Svinkin et al., GCN Circ. 28844)
triggered Konus-Wind at T0=65207.923 s UT (18:06:47.923).
The burst light curve shows a multi-peaked structure
which starts at ~T0-14 s, peaks at ~T0+1.5, and ends at ~T0+20 s,
followed by a weaker emission seen up to ~T0+91 s.
The total burst duration is ~105 s.
The emission is seen up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB201103_T65207/
As observed by Konus-Wind, the burst
had a fluence of 5.26(-0.77,+0.82)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.536 s,
of 1.49(-0.24,+0.25)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+16.640 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.72(-0.16,+0.19),
the high energy photon index beta = -2.54(-1.13,+0.33),
the peak energy Ep = 403(-60,+74) keV
(chi2 = 102/97 dof).
The spectrum near the maximum count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.71(-0.12,+0.13)
and Ep = 466(-47,+58) keV (chi2 = 104/98 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.4
(chi2 = 102/97 dof).
Assuming the redshift z=1.105 (Xu et al., GCN Circ. 28847)
and a standard cosmology model with H_0 = 67.3 km/s/Mpc,
Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~1.8x10^53 erg,
the peak luminosity L_iso is ~1.1x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,z,i is ~850 keV.
With these values, GRB 201103B is consistent with the 'Amati'
and 'Yonetoku' relations built for 316 KW GRBs with known z
classified as Type II (Tsvetkova et al., ApJ 2020 submitted).
The 68% and 90% prediction bands for Type II are show with
dark and light shaded regions, respectively, see
http://www.ioffe.ru/LEA/GRBs/GRB201103_T65207/GRB201103B.pdf
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 28863
Subject
GRB 201103B: GMG observation (2nd epoch)
Date
2020-11-07T16:02:50Z (5 years ago)
From
Jirong Mao at Yunnan Obs <jirongmao_obs@ynao.ac.cn>
J. Mao, C.-J. Wang, and J.-M. Bai (YNAO) report:
We observed the field of GRB201103B/ZTF20acozryr/AT2020yxz with
the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan
Observatories once again. The observation began at UT 14:27:51, 7th,
Nov. 2020. We clearly detected the source, and the preliminary magnitude
is measured to be R~20.9. It seems that the source is fading very slightly.
We suggest to perform both photometric monitors to obtain the variability
behavior and spectral observations to obtain the possible spectral evolution
in the following nights.
GCN Circular 28861
Subject
GRB201103B: GMG observation
Date
2020-11-07T12:16:59Z (5 years ago)
From
Jirong Mao at Yunnan Obs <jirongmao_obs@ynao.ac.cn>
J. Mao, C.-J. Wang, and J.-M. Bai (YNAO) report:
We observed the field of GRB201103B/ZTF20acozryr/AT2020yxz with the 2.4-meter optical telescope
at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at UT 16:41:52, 6th,
Nov. 2020. We clearly detected the source, and the preliminary magnitude is measured to be R~20.6.
GCN Circular 28858
Subject
Swift XRT and UVOT detection of ZTF20acozryr/AT2020yxz/GRB201103B
Date
2020-11-06T17:44:52Z (5 years ago)
From
Boris Sbarufatti at PSU <bxs60@psu.edu>
P. A. Evans (U Leicester), N. P. M. Kuin (UCL-MSSL) and B. Sbarufatti (PSU) report on behalf of the Swift team:
Swift-XRT has performed follow-up observations of the ZTF-detected afterglow candidate ZTF20acozryr/AT2020yxz, (Coughlin et al., GCN 28841) proposed to be associated with the AGILE and IPN-detected GRB 201103B (Ursi et al., GCN Circ. 28831, Svinkin et al., GCN Circ. 28844), collecting 1.2 ks of Photon Counting (PC) mode data between T0+199.5 ks and T0+206.0 ks.
An uncatalogued X-ray source is detected, at RA, Dec=42.1842, +12.1382 which is equivalent to:
RA (J2000): 02:48:44.21
Dec(J2000): +12:08:17.6
with an uncertainty of 5.3 arcsec (radius, 90% confidence). This position is 3.8 arcsec from the ZTF position, consistent with that source. We cannot determine at the present time whether the source is fading.
The mean count-rate of the source is (1.5 +/- 0.5) x 10^-3 ct/sec, and we cannot yet confirm any variability.
This location has been previously observed by Swift in 2014 November, and these observations are in the 2SXPS catalogue (Evans et al., 2020):
https://www.swift.ac.uk/2SXPS/doSimpleSearch.php?searchpos=42.18421+12.1382&searchrad=750&getWhat=1&subset=1&dssubset=0&coordType=0&retType=0&searchWhat=1
The stacked image (field 10000005379) created from the 2014 observation contained about 2043 s of exposure at this position, and contained only 2 events at the ZTF location, giving a 3-sigma upper limit of 5.4 x 10^-3 ct/sec. Thus the XRT source reported above is a transient event, and we identify it as the X-ray afterglow to GRB 201103B.
It has been pointed out to us that we incorrectly stated in GCN 28849 that the nature of the object had not been confirmed, whereas Xu et al (GCN Circ. 28847) has in fact confirmed the associated with the GRB via their spectroscopy. We apologize for the confusion.
The automated analysis of this object is available at https://www.swift.ac.uk/xrt_products/00021039
A source is also detected in UVOT data with magnitude B=20.25+-0.26 at ~T+205 ks. A weak signal is also detected in the V band at less than 3 sigma significance (V > 19.6) with some evidence of fading.
This circular is an official product of the Swift XRT and UVOT teams.
GCN Circular 28854
Subject
GRB 201103B (ZTF20acozryr/AT2020yxz): Xinglong-2.16m optical observations
Date
2020-11-06T16:03:42Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu, L.P. Xin, J.Y. Wei, D. Xu (NAOC)
report on behalf of a larger collaboration:
We observed the field of ZTF20acozryr/AT2020yxz (Coughlin et al. GCN
28841), likely the optical afterglow of GRB 201103B (Svinkin et al., GCN
28844), using the 2.16m telescope equipped with the BFOSC camera at
Xinglong, Hebei, China. Observations started at 14:12:36 UT on
2020-11-06, and 8x180s R-band frames were obtained.
The source is clearly detected in our stacked image, with R = 20.36 +/-
0.05 mag at Tmid-T0 = 2.8373 days post-burst, calibrated with nearby
Pan-STARRS1.
We acknowledge excellent support from the Xinglong-2.16m observing
staff, in particular Jie Zheng.
GCN Circular 28847
Subject
GRB 201103B (ZTF20acozryr/AT2020yxz): VLT/X-shooter redshift
Date
2020-11-06T04:58:38Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
D. Xu (NAOC), J.-B. Vielfaure (APC, Paris University), D. A. Kann
(HETH/IAA-CSIC), D. B. Malesani (DTU Space), D. A. Perley (LJMU), A. J.
Levan (Radboud U. Nijmegen), S. Klose, B. Stecklum (both TLS Tautenburg),
K. Wiersema (Univ. Warwick), and A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI)
report on behalf of the Stargate Consortium:
We observed the transient ZTF20acozryr/AT2020yxz (Coughlin et al., GCN
28841), which has been proposed to be the optical afterglow of GRB
201103B (Svinkin et al., GCN 28844) using the ESO VLT UT3 (Melipal)
equipped with the X-shooter spectrograph. Our spectra cover the
wavelength range 3000-21000 AA, and consist of 4 exposures of 1200 s
each. The observation mid-time was 2020 Nov 6.116 UT (56.66 hr/2.361
days after the GRB).
In a 60 s image taken with the acquisition camera on Nov 6.0771 UT, we
detect the optical afterglow, for which we measure a preliminary
magnitude r ~ 20.7 mag (AB magnitude, calibrated against a nearby galaxy
from the Pan-STARRS catalog; Chambers et al. 2016, arXiv:1612.05560).
We clearly detect continuum over the entire wavelength range. From
detection of multiple absorption features, which we interpret as due to
CII, MgII, and multiple FeII lines, we infer a redshift z = 1.105. We
suggest this to be the redshift of the transient, which we hereby
confirm spectroscopically to be the afterglow of GRB 201103B.
We acknowledge excellent support from the ESO observing staff in Paranal,
in particular Ivan Aranda and Matias Jones.
[GCN OPS NOTE(04nov2020): Per author's request, Ivan Aranda and Matias Jones
were added to the last sentence.]
[GCN OPS NOTE(07nov20): Per author's request, Stecklum was added
to the author's list.]
GCN Circular 28846
Subject
GRB 201103B (ZTF20acozryr/AT2020yxz): Nanshan/NEXT-0.6m optical observations
Date
2020-11-06T02:36:07Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
D. Xu (NAOC), Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu (NAOC), X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the optical transient, ZTF20acozryr/AT2020yxz, an likely
orphan GRB optical afterglow when discovered by ZTF (Coughlin et al.,
GCN 28841) and later confirmed by the IPN localisation as the optical
afterglow of GRB 201103B (Svinkin et al., GCN 28844), using the
NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.
Observations started at 17:33:06 UT on 2020-11-05 and a series of 120s
exposures were obtained in the Sloan r-filter.
Considering the IPN trigger time, 18:06:47 UT on 2020-11-03, as the
onset of the burst, preliminary photometry results are as follows:
T_mid_obs (UT) T_mid_grb(day) Mag MagErr
2020-11-05T17:43:35 1.984 20.5 0.3
2020-11-05T18:31:28 2.017 20.8 0.2
calibrated with nearby PS1 stars.
Compared with the ZTF photometry, such a decay is consistent with that
of a conventional GRB optical afterglow.
GCN Circular 28844
Subject
IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
Date
2020-11-06T00:20:30Z (5 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
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,
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. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team,
A. Ursi, N. Parmiggiani, F. Verrecchia, A. Bulgarelli,
A. Trois, M. Marisaldi, C. Pittori, M. Tavani, Y. Evangelista,
I. Donnarumma, M. Cardillo, G. Piano, G. Minervini, A. Argan,
F. Lucarelli, A. Zoli, V. Fioretti, F. Fuschino, M. Pilia,
F. Longo, A. Giuliani on behalf of the AGILE 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, bright GRB 201103B
(AGILE detection: Ursi et al., GCN Circ. 28831)
has been detected by AGILE, Konus-Wind, INTEGRAL (SPI-ACS),
Mars-Odyssey (HEND), and Swift (BAT),
so far, at about 65207 s UT (18:06:47).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
42.089 (02h 48m 21s) +12.441 (+12d 26' 29")
Corners:
41.830 (02h 47m 19s) +14.128 (+14d 07' 41")
42.595 (02h 50m 23s) +11.069 (+11d 04' 07")
42.244 (02h 48m 59s) +10.759 (+10d 45' 32")
41.511 (02h 46m 03s) +13.781 (+13d 46' 52")
---------------------------------------------
The error box area is 1.24 sq. deg, and its maximum
dimension is 3.4 deg (the minimum one is 23.8 arcmin).
The Sun distance was 175 deg.
This box may be improved.
The distance between the optical transient ZTF20acozryr/AT2020yxz (Coughlin
et al., GCN Circ. 28841) and the IPN box center is 19 arcmin, thus
confirming the association of the burst and the OT.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB201103_T65207/IPN
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 28831
Subject
GRB 201103B: AGILE detection
Date
2020-11-04T21:05:06Z (5 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), 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),
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 a burst at T0 = 2020-11-03 18:06:45.36 +/-
0.01 s (UTC), reported by INTEGRAL/SPI-ACS (trigger ID 8788,0).
The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and
AntiCoincidence (AC; 50-200 keV) detectors. The event lasted ~7 s and
released a total number of 1850 counts in the SA detector (above a
background rate of 90 Hz), 25200 counts in the MCAL detector (above a
background rate of 1260 Hz), and 73000 counts in the AC detector (above a
background rate of 3650 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/GRB_201103B_AGILE_RM.png .
The event also triggered a partial high time resolution MCAL data
acquisition.
Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert
Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
[GCN OPS NOTE(06Nov20): Due to the uncertainty of the arrival time with respect
to the downtime window (15 hours) of the GCN Circulars processing system,
the error in the date-time in the header of this Circular can be off anywhere from 0-15 hours.]