GRB 200716C
GCN Circular 28154
Subject
GRB 200716C: Kitab optical observations
Date
2020-07-23T09:34:07Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), A. Zhornichenko (KIAM), A.
Novichonok (Petrozavodsk State University, KIAM), Sh. Ehgamberdiev
(UBAI) report on behalf of IKI-GRB-FuN:
We observed GRB 200716C (Fermi GBM team, GCN 28123; Ukwatta et al GCN
28124; Ohno et al., GCN 28130; Ursi et al., GCN 28133; Torii et al., GCN
28139; Xue et al., GCN 28145; Frederiks et al., GCN 28147) with RC-36
telescope of Kitab observatory starting July 17 (UT) 17:24:57. The
optical afterglow (Ukwatta et al., GCN 28124; Lipunov et al., GCN 28125;
Hu et al., GCN 28126; Kumar et al., GCN 28138; Gokuldass et al., GCN
28146; Jelinek et al., GCN 28149; Pozanenko et al., GCN 28151; Kann et
al., GCN 28152) is detected in a stacked image. Despite we do not
detect possible host galaxy (D���Avanzo et al., GCN 28132) the galaxy may
contaminate photometry result. Preliminary photometry of the afterglow
is following
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2020-07-17 17:24:57 0.78952 R 59*60 18.2 0.3 18.6
The photometry is based on nearby stars of USNO-B1.0
USNO-B1.0_id R2
1196-0207884 15.42
1197-0206830 14.99
GCN Circular 28152
Subject
GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
Date
2020-07-21T21:36:27Z (5 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
D. A. Kann (HETH/IAA-CSIC), M. Jelinek (ASU CAS Ondrejov), L. Izzo
(DARK/NBI), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. C.
Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), B. Arroyo,
G. Bergond, and S. Pedraz (all CAHA) report:
We observed the position of the afterglow (Ukwatta et al., GCN 28124;
Lipunov et al., GCN 28125; Hu et al., GCN 28126; Kumar et al., GCN
28138; Gokuldass et al., GCN 28146; Jelinek et al., GCN 28149; Pozanenko
et al., GCN 28151) and potential host galaxy (D'Avanzo, GCN 28132) of
the bright GRB 200716C (Swift detection: Ukwatta et al., GCN 28124;
Fermi GBM/LAT detections: Veres & Meegan, GCN 28135/Ohno et al., GCN
28130; AGILE detection: Ursi et al., GCN 28133; CALET detection: Torii
et al., GCN 28139; Insight-HXMT/HE detection: Xue et al., GCN 28145)
with the 2.2m telescope at Calar Alto, Almeria, Spain, equipped with
CAFOS. We obtained a 180 s image in SDSS r', starting 2020-07-17
20:37:13 UT, (mid-time 0.903495 days after the GRB trigger), at high
airmass.
The host galaxy is clearly visible, but there is no clear detection of
the afterglow. Calibrating against four nearby SDSS stars, we measure r'
= 19.67 +/- 0.07 mag (AB mag). This value is fainter than those given by
Pozanenko et al., GCN 28151, but we caution that an uneven background
nearby may be influencing our magnitude measurement somewhat. Therefore,
we are in agreement with Pozanenko et al. that the afterglow was not
distinguishable from the host galaxy anymore at this point in time.
Combining the above-mentioned sources and the automatically reduced UVOT
data (but excluding the point from Kumar et al.), we find the afterglow,
starting with the second Swift orbit, decays according to a broken
power-law with decay slopes alpha_1 = 0.80 +/- 0.04, alpha_2 = 5.5 +/-
1.3, and break time 0.44 +/- 0.03 days. Hereby, we estimated host galaxy
magnitudes in UVOT ubv based on the magnitudes given by D'Avanzo, GCN
28132, and assumed a significantly fainter host in the UV filters. Even
compared to this extreme fit, the data point given by Kumar et al. is
nearly two magnitudes too bright, as the steep decay should have set on
already here assuming it is achromatic. While we caution the second
decay slope depends strongly on the assumed host magnitudes, even
without a host there is clearly a break to a very steep decay seen in
uvw2, b, white, and partially v.
This behavior is in strong contrast to the X-rays, which show an
unbroken decay at alpha_X = 1.56 across this time span (Page & Evans,
GCN 28131). Combined with indications from the Konus-Wind analysis that
this may actually be a non-collapsar event (Frederiks et al., GCN
28148), this points to this being an event of interest. Further
follow-up is warranted.
[GCN OPS NOTE(21jul20): Due to some non-printing characters in the
Subject-line of the submission, the MIME processor left a large chunk
of the header of the submission email to appear as more of the body
of the email. This has been removed from the archive copies.]
GCN Circular 28151
Subject
GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
Date
2020-07-21T15:34:11Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), S. Belkin (IKI), V. Rumyantsev (CrAO), A. Gorshkov
(INASAN), V. Kim (AFIF, Pulkovo Observatory), N. Pankov (HSE), K.
Kamyshnikov (HSE), M. Krugov (AFIF), A. Volnova (IKI), E. Mazaeva
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed GRB 200716C (Fermi GBM team, GCN 28123; Ukwatta et al GCN
28124; Torii et al., GCN 28139; Xue et al., GCN 28145; Frederiks et
al., GCN 28147) with ZTSH 2.6m telescope of CrAO observatory,
Zeiss-2000 of Terskol observatory, and AZT-20 telescope of Assy-Turgen
observatory. The optical afterglow (Ukwatta et al., GCN 28124; Lipunov
et al., GCN 28125; Hu et al., GCN 28126; Kumar et al., GCN 28138;
Gokuldass et al., GCN 28146; Jelinek et al., GCN 28149) and possible
host galaxy (D���Avanzo et al., GCN 28132) is detected in a stacked
image. Preliminary photometry of the (afterglow + possible host galaxy)
is following
Date UT start t-T0 Filter Exp. OT Err. UL Telescope
(mid, days) (s)
2020-07-17 19:17:52 0.84735 R 29*60 19.04 0.03 22.0 ZTSh
2020-07-17 19:50:49 0.87023 R 30*60 19.21 0.03 21.9 ZTSh
2020-07-18 18:33:32 1.83323 R 24*120 19.21 0.06 22.1 Zeiss-2000
2020-07-18 19:25:19 1.85253 R 17*60 19.21 0.06 22.1 ZTSh
2020-07-19 17:15:50 2.78066 r' 52*60 19.31 0.03 22.4 AZT-20
The photometry is based for R-calibration on the star
USNO-B1.0_id R
1196-0207871 16.18
and nearby SDSS stars for r' calibration
SDSS-DR12_id r
J130423.13+294053.3 15.970
J130352.15+293733.9 16.592
J130416.16+293906.8 16.914
The above photometry besides of the first observation is consistent
with a brightness of possible host in USNO-B1.0 (R2=19.23) and in SDSS
DR12 (r'= 19.301 +/- 0.026). We may conclude that we detected afterglow
only in the first observation on 0.84735 days after trigger at R=19.04
+/- 0.03.
GCN Circular 28149
Subject
GRB 200716C: FRAM-ORM afterglow detection
Date
2020-07-21T09:04:42Z (5 years ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek,
Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza
(Institute of Physics, Prague, CZ)
report:
The 25cm robotic telescope FRAM-ORM at La Palma (Spain)
reacted robotically to the alert of GRB200716C (Ukwatta
et al GCNC 28124), obtaining a series of 20s unfiltered
images starting at 22:58:17.9 UT, i.e. 36.5s post trigger.
We clearly detect the source reported by other telescopes
(Ukwatta et al GCN 28124, Lipunov et al GCN 28125, Hu et al
GCN 28126) as it rises slowly. The brightness of the object
reaches maximum several minutes after the trigger with R =
16.1 and then it decays until the end of our dataset 2.4 h
after the trigger.
GCN Circular 28148
Subject
Konus-Wind observation of GRB 200716C: correction to GCN 28147
Date
2020-07-20T12:49:52Z (5 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, D. Svinkin, S. Golenetskii, R.Aptekar, A.Lysenko,
A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The GRB 200716C (Swift-BAT detection: Ukwatta et al., GCN 28124;
Fermi-LAT detection: Ohno et al., GCN 28130;
AGILE-MCAL detection: Ursi et al., GCN 28133;
Fermi-GBM detection: Veres & Meegan, GCN 28135;
CALET-GBM detection: Torii et al., GCN 28139;
Insight-HXMT/HE detection: Xue et al., GCN 28145)
triggered Konus-Wind (KW) at T0=82658.337 s UT (22:57:38.337).
The burst light curve shows two bright, short, hard-spectrum pulses
in the interval from ~T0-0.5 s to ~T0+2.5 s.
Both pulses are ~0.5 s wide and they are peaked
at ~T0+0.128 s and ~T0+2.096 s, respectively.
A much weaker extended post-burst emission is visible
in the KW 20-80 keV band up to ~T0+75 s.
The emission in the main pulses is seen up to ~7 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/
As observed by Konus-Wind, the burst had
a fluence of (1.2 +/- 0.2)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0+0.128 s,
of (3.7 +/- 0.6)x10^-5 erg/cm^2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.07(-0.12,+0.14)
and Ep = 652(-154,+241) keV (chi2 = 91/97 dof).
Fitting by a GRB (Band) model yields similar alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.0
(chi2 =91/96 dof).
The spectrum near the peak count rate (measured from T0
to T0+0.256 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.51 (-0.19,+0.31),
the high energy photon index beta = -2.23 (-0.58,+0.29),
the peak energy Ep = 616 (-200,+226) keV,
(chi2 = 48/42 dof).
Assuming the photo z=0.348 of a possible host galaxy (D'Avanzo, GCN 28132)
and a standard cosmology 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 ~ 3.9x10^51 erg,
the peak luminosity L_iso ~ 1.6x10^52 erg/s,
and the rest-frame peak energy of the time-integrated (peak)
spectrum Ep,z ~ 880 keV (~830 keV).
With these values, GRB 200716C is a clear outlier in the 'Amati' relation
built for 138 long KW GRBs with known z (Tsvetkova et al., ApJ 850 161, 2017).
Meanwile, in both Eiso-Ep,z and Liso-Ep,z planes, the GRB 200716C position
is consistent with short-hard (Type I) GRB population,
see http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/GRB200716C.pdf
All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.
GCN Circular 28147
Subject
Konus-Wind observation of GRB 200716C
Date
2020-07-19T23:32:33Z (5 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Frederiks, D. Svinkin, S. Golenetskii, R.Aptekar, A.Lysenko,
A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The GRB 200716C (Swift-BAT detection: Ukwatta et al., GCN 28124;
Fermi-LAT detection: Ohno et al., GCN 28130;
AGILE-MCAL detection: Ursi et al., GCN 28133;
Fermi-GBM detection: Veres & Meegan, GCN 28135;
CALET-GBM detection: Torii et al., GCN 28139;
Insight-HXMT/HE detection: Xue et al., GCN 28145)
triggered Konus-Wind (KW) at T0=82658.337 s UT (22:57:38.337).
The burst light curve shows two bright, short, hard-spectrum pulses
in the interval from ~T0-0.5 s to ~T0+2.5 s.
Both pulses are ~0.5 s wide and they are peaked
at ~T0-0.128 s and ~T0+2.096 s, respectively.
A much weaker post-burst emission is visible
in the KW 20-80 keV band up to ~T0+75 s.
The emission in the main pulses is seen up to ~7 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/
As observed by Konus-Wind, the burst had
a fluence of (1.2 +/- 0.2)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0+0.128 s,
of (3.7 +/- 0.6)x10^-5 erg/cm^2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.07(-0.12,+0.14)
and Ep = 652(-154,+241) keV (chi2 = 91/97 dof).
Fitting by a GRB (Band) model yields similar alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.0
(chi2 =91/96 dof).
The spectrum near the peak count rate (measured from T0
to T0+0.256 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.51 (-0.19,+0.31),
the high energy photon index beta = -2.23 (-0.58,+0.29),
the peak energy Ep = 616 (-200,+226) keV,
(chi2 = 48/42 dof).
Assuming the photo z=0.348 of a possible host galaxy (D'Avanzo, GCN 28132)
and a standard cosmology 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 ~ 3.9x10^51 erg,
the peak luminosity L_iso ~ 1.6x10^52 erg/s,
and the rest-frame peak energy of the time-integrated (peak)
spectrum Ep,z ~ 880 keV (~830 keV).
With these values, GRB 200716C is a clear outlier in the 'Amati' relation
built for 138 KW GRBs with known z (Tsvetkova et al., ApJ 850 161, 2017).
Meanwile, in both Eiso-Ep,z and Liso-Ep,z planes, the GRB 200716C position
is consistent with short-hard (Type I) GRB population,
see http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/GRB200716C.pdf
All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.
[GCN OPS NOTE(20jul20): Please see GCN Circ 24128 for a couple corrections.]
GCN Circular 28146
Subject
GRB 200716C: VIRT optical detection.
Date
2020-07-19T22:10:18Z (5 years ago)
From
Priyadarshini Gokuldass at U. of the Virgin Islands <priyadass.94@gmail.com>
P. Gokuldass (UVI), D. Morris (UVI), N. Orange (OrangeWave Innovative
Science, LLC), A. Cucchiara (UVI/College of Marin), R. Strausbaugh (UVI)
report:
We observed the field of GRB200716C (Ukwatta et al, GCN 28124) with the
0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 07-17-2020 starting at 01:48:10 UT (T+2.8
hrs). We performed a series of exposures in R filter with a total exposure
of 1210 s. The weather conditions were clear during the hours of
observation with an average airmass of 2.2.
We detect a source consistent with the UVOT position (Ukwatta et al, GCN
28124) and optical transient identified by others (Lipunov et al. 28125, Hu
et al. 28126, Kumar et al. 28138) with magnitude:
R= 17.1 +/- 0.2
The magnitude is estimated from comparison to nearby USNO B1 stars and is
not corrected for Galactic extinction. Further analysis is in progress to
confirm the decaying nature of the source. The VIRT is still in the
commissioning phase.
This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR AST
Award 1901296, and NSF HBCU-UP AST Award 1831682. This message can be cited.
GCN Circular 28145
Subject
GRB 200716C: Insight-HXMT/HE detection
Date
2020-07-19T10:56:08Z (5 years ago)
From
Wangchen Xue at IHEP <xuewc@ihep.ac.cn>
W. C. Xue, S. Xiao, Q. B. Yi, Y. G. Zheng, C. Cai, Q. Luo,
C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang,
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song,
M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
At 2020-07-16T22:57:41.18 (T0), Insight-HXMT/HE detected
GRB 200716C (trigger ID: HEB200716956) in a routine search of the data,
which also triggered Fermi/GBM (Fermi GBM team, GCN #28123),
Swift/BAT (Ukwatta et al., GCN #28124), Fermi-LAT (Ohno et al., GCN #28130)
and CALET GBM (Torii et al., GCN #28139).
The Insight-HXMT/HE light curve mainly consists of multiple
pulses with a duration (T90) of 2.16 s measured from T0+0.19 s.
The 1-ms peak rate, measured from T0+0.31 s, is 27488 cnts/sec.
The total counts from this burst is 6590 counts.
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB200716956_lc.jpg
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (deposited energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.
Insight-HXMT is the first Chinese space X-ray telescope, which was
funded jointly by the China National Space Administration (CNSA) and
the Chinese Academy of Sciences (CAS).
More information about it could be found at:
http://www.hxmt.org.
GCN Circular 28139
Subject
GRB 200716C: CALET Gamma-Ray Burst Monitor detection
Date
2020-07-18T12:06:31Z (5 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
S. Torii (Waseda U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The bright GRB 200716C (Swift detection: Ukwatta et al., GCN Circ. 28124,
Barthelmy et al., GCN Circ. 28136; Fermi-LAT detection: Ohno et al.,
GCN Circ. 28130; Fermi GBM detection: Veres and Meegan, GCN Circ. 28135;
https://gcn.gsfc.nasa.gov/other/200716C.gcn3) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 22:57:41.346 UTC on 16 July 2020.
The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script,
the GCN notice was not distributed automatically for this event.
The burst light curve shows two narrow pulses followed by a weak tail. The
emission starts at T-0.1 sec and ends at T+6.8 sec. The T90 and T50
durations measured by the SGM data are 5.3 +- 1.1 sec and 1.9 +- 0.1 sec
(40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1278975378/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.
GCN Circular 28138
Subject
GRB 200716C: Optical observations from HCT
Date
2020-07-18T12:03:42Z (5 years ago)
From
Brajesh Kumar at Indian Inst. of Astrophysics <brajesh.kumar@iiap.res.in>
Brajesh Kumar (ARIES, Nainital), Anirban Dutta, Avinash Singh, G. C.
Anupama, D. K. Sahu and Pramod Kumar (IIA, Bengaluru)
We observed the field of GRB 200716C (Fermi GBM, GCN #28123; Ukwatta et
al., GCN #28124) with the Himalaya Faint Object Spectrograph and Camera
(HFOSC) mounted on the 2-m Himalayan Chandra Telescope (IAO, Hanle,
India). Multiple frames (each 300 sec) of the GRB field in Bessell R and
I bands were obtained under moderate sky conditions. Preliminary PSF
photometry on the stacked images was performed and calibrated against
USNO-B1 catalogue. The estimated magnitudes are listed below:
DATE | UT (mean) | Exposure | Filter | Mag
2020-07-17 17:06:34 300x3 R 17.55 +/- 0.18
2020-07-17 17:23:33 300X3 I 17.19 +/- 0.15
Here, we caution that there is an extended object near the GRB location
(possibly the host galaxy, D'Avanzo et al. GCN #28132). However, the
extended source is fainter (~19.23 and ~18.67 mag in R and I bands,
respectively, USNO-B1). Therefore, the estimated magnitudes likely
belong to the OT candidate (Lipunov et al., GCN #28125; Hu et al., GCN
#28126), affected by the host contamination.
We thank the staff at IAO and CREST for helping with the observations.
GCN Circular 28136
Subject
GRB 200716C: Swift-BAT refined analysis
Date
2020-07-17T20:26:57Z (5 years ago)
From
Tilan Ukwatta at LANL <tilan.ukwatta@gmail.com>
S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF),S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the
recent telemetry downlink, we report further analysis
of BAT GRB 200716C (trigger #982707)
(Ukwatta, et al., GCN Circ. 28124). The BAT ground-calculated
position is RA, Dec = 196.011, 29.636 deg which is
RA(J2000) = 13h 04m 02.5s
Dec(J2000) = +29d 38' 08.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat,
90% containment). The partial coding was 57%.
The mask-weighted light curve shows two prominent peaks,
first at ~T+0.1 s and the second at ~T+2.1. Significant
activity is still visible until ~T+90 s. T90 (15-350 keV) is
86 +- 17 sec (estimated error including systematics).
The time-averaged spectrum from T-0.42 to T+112.63 sec is best
fit by a simple power-law model. The power law index of the
time-averaged spectrum is1.65 +- 0.09. The fluence in the
15-150 keV band is 3.6 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak
photon flux measured from T-0.18 sec in the 15-150 keV band
is 10.7 +- 0.5 ph/cm2/sec. All the quoted errors are at the
90% confidencelevel.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/982707/BA/
GCN Circular 28135
Subject
GRB 200716C: Fermi GBM detection
Date
2020-07-17T16:02:54Z (5 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
P. Veres (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 22:57:41.18 UT on 16 July 2020, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered
and located GRB 200716C (trigger 616633066 / 200716957) which was also
detected by the Swift (Ukwatta et al., GCN 28124), Fermi-LAT (Ohno et al.,
GCN 28130). The GBM on-ground location is consistent with both the Swift
and Fermi-LAT positions.
The angle from the Fermi LAT boresight at the GBM trigger time is 37
degrees.
The GBM light curve shows two overlapping pulses with a duration (T90) of
about 5.3 s (50-300 keV). The time-averaged spectrum from T0-0.26 s to
T0+4.9 s is best fit by a power law function with an exponential high-energy
cutoff. The power law index is -1.07 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 716 +/- 97 keV.
The event fluence (10-1000 keV) in this time interval is (9.57 +/- 0.25)E-6
erg/cm^2. The 1-sec peak photon flux measured starting from T0 + 64 ms in
the 10-1000 keV band is 19.3 +/- 0.3 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 28133
Subject
GRB 200716C: AGILE/MCAL detection
Date
2020-07-17T10:49:24Z (5 years ago)
From
Francesco Verrecchia at SSDC,INAF-OAR <francesco.verrecchia@ssdc.asi.it>
A. Ursi (INAF/IAPS), 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, C. Pittori
(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 Mini-CALorimeter (MCAL) detected the GRB 200716C at T0 =
2020-07-16 22:57:41.38 +/- 0.01 s (UTC), reported by Swift-BAT (GCN #28122,
#28124), Fermi-GBM (GCN #28123), BOOTES-1 (GCN #28126), Swift-XRT (GCN
#28128, #28129, #28131), and Fermi-LAT (GCN #28130).
The event consists of two main episodes, lasting ~0.64 s and ~0.26 s,
respectively, which released a total number of 623 counts and 416 counts
in the detector (in the 0.4-100 MeV energy range), above an average
background rate of 650 Hz.
The time-integrated spectrum of the first episode can be fitted in the
energy range 0.4-20 MeV with single power-law with ph.ind. = 2.40
-0.29/+0.32, resulting in a reduced chi-squared of 1.15 (21 d.o.f.) and a
fluence of 4.6e-06 ergs/cm^2 (90% confidence level). The time-integrated
spectrum of the second episode can be fitted in the energy range 0.4-20
MeV with single power-law with ph.ind. = 2.51 -0.37/+0.43, resulting in a
reduced chi-squared of 1.08 (21 d.o.f.) and a fluence of 5.7e-06 ergs/cm^2
(90% confidence level).
The MCAL light curve can be found at
http://www.agilescienceapp.it/notices/GRB_068714_522025061.386471.png .
The event is also clearly visible in the scientific ratemeters (RMs) of
the MCAL (0.4-100 MeV) and Anti-Coincidence (50-200 keV) detectors. Their
light curves can be found at
http://www.agilescienceapp.it/notices/GRB200716C_AGILE_RMs.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. Automatic MCAL GRB alert Notices can be found at:
https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN Circular 28132
Subject
GRB 200716C: possible host galaxy from the SDSS
Date
2020-07-17T09:34:53Z (5 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
P. D���Avanzo (INAF-OAB), on behalf of the CIBO collaboration report:
Inspection of the SDSS reveals the presence of an extended object, classified as a galaxy, at a position consistent (within ~ 1���)
with the one reported for the optical afterglow of GRB 200716C (Ukwatta et al., GCN Circ. 28124; Lipunov et al., GCN Circ. 28125;
Hu et al., GCN Circ. 28126).
According to the SDSS DR16 this galaxy has AB magnitudes:
u = 21.48 +/- 0.21,
g = 20.46 +/- 0.05,
r = 19.29 +/- 0.03,
i = 18.88 +/- 0.03,
z = 18.54 +/- 0.09
and a photoz = 0.348 +/- 0.053.
Further details can be found at the following link:
http://skyserver.sdss.org/dr16/en/tools/explore/Summary.aspx?id=1237665442053095703
This object can be the host galaxy of GRB 200716C.
GCN Circular 28131
Subject
GRB 200716C: Swift-XRT refined analysis correction
Date
2020-07-17T07:01:57Z (5 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
K.L. Page and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT
team:
GCN 28129 (Gropp et al.) incorrectly included a sentence that stated it
was not possible to tell if the X-ray afterglow of GRB 200716C was fading.
In fact, the first snapshot of data shows a complicated structure, which
can be modelled by changes in slope and overlapping flares. The late-time
light curve (from T0+4.3 ks) can be modelled with a power-law decay with a
decay index of alpha=1.56 (+/-0.11).
This circular is an official product of the Swift-XRT team.
GCN Circular 28130
Subject
GRB 200716C: Fermi-LAT detection
Date
2020-07-17T06:53:04Z (5 years ago)
From
Nicola Omodei at Stanford U. <nicola.omodei@slac.stanford.edu>
M. Ohno (Hiroshima Univ/Eotvos Univ.), M. Arimoto (Kanazawa Univ.), N. Di Lalla, N. Omodei (Stanford University), F. Longo (University and INFN, Trieste),
report on behalf of the Fermi-LAT Collaboration:
On July, 16th, 2020, Fermi-LAT detected high-energy emission from GRB 200716C, which was also detected by Fermi-GBM (trigger 616633066.180458/200716957; Fermi GBM Team GCN 28123) and Swift (Ukwatta et al. GCN 28124).
The best LAT on-ground location is found to be RA, Dec = 195.7, 29.9 (degrees, J2000) with an error radius of 0.3 deg (90% containment, statistical error only).
The best LAT position is consistent with the Swift position. This was 6 deg from the LAT boresight at the time of the GBM trigger: T0 = 22:57:41 UT.
The data from the Fermi-LAT show a significant increase in the event rate after the GBM trigger that is spatially correlated with the GBM emission with high significance.
The photon flux above 100 MeV in the time interval 0-1000 s after the GBM trigger is 5.3e-6 +/- 2.0e-6 ph/cm2/s.
The estimated photon index above 100 MeV is -1.9+/-0.2.
The highest-energy photon is a 8.2 GeV event which is observed 152 seconds after the GBM trigger.
The Fermi-LAT point of contact for this burst is
Nicola Omodei (nicola.omodei@stanford.edu).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular 28129
Subject
GRB 200716C: Swift-XRT refined Analysis
Date
2020-07-17T06:44:34Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo
(INAF-OAB) and T.N. Ukwatta report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 200716C (Ukwatta et al. GCN
Circ. 28124), from 86 s to 23.1 ks after the BAT trigger. The data
comprise 578 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN Circ. 28128). We cannot determine at the
present time whether the source is fading.
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.56 (+/-0.03). The
best-fitting absorption column is 5.8 (+1.0, -0.9) x 10^20 cm^-2, in
excess of the Galactic value of 1.1 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.45 (+0.13, -0.05)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 4.4 x 10^-11 (4.4 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.1 (+2.3, -0.0) x 10^20 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.45 (+0.13, -0.05)
If the light curve continues to decay with a power-law decay index of
1.46, the count rate at T+24 hours will be 8.5 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.7 x
10^-13 (3.8 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00982707.
This circular is an official product of the Swift-XRT team.
GCN Circular 28128
Subject
GRB 200716C: Enhanced Swift-XRT position
Date
2020-07-17T05:32:43Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1666 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 200716C, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 196.01029, +29.64407 which is equivalent
to:
RA (J2000): 13h 04m 2.47s
Dec (J2000): +29d 38' 38.6"
with an uncertainty of 1.5 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 28126
Subject
GRB200716C: BOOTES-1 optical afterglow detection
Date
2020-07-17T03:29:41Z (5 years ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:
Following the Swift trigger of GRB 200716C (Ukwatta et al., GCNC 28124), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this burst. Series images were taken started 22:58:53UT (72 s after trigger). In the first 10s image, the afterglow reported by UVOT (Ukwatta et al., GCNC 28124) and MASTER (Lipunov et al., GCNC 28125) is detected with magnitude of 16.8 (clear filter). Further observation are on going.
We thank the staff at INTA-CEDEA for their excellent support.
GCN Circular 28125
Subject
Swift GRB200716C: Global MASTER-Net OT detection
Date
2020-07-16T23:41:37Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina,
P.Balanutsa,
A.Kuznetsov, D. Vlasenko, F. Balakin, I. Gorbunov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk
D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory
R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
MASTER-IAC robotic telescope (Global MASTER-Net:
http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,
vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to
the GRB200716C (Ukwatta et al, GCN 28124) 55 sec after notice time and
79 sec after trigger time at 2020-07-16 22:59:00 UT.
On our 5-th (50s exposure) set , obtained 243 sec after tigger time
at 2020-07-16 23:01:45 UT, we found an optical transient within Swift
error-box (ra=196.012 dec=29.6292 r=0.05) brighter.
T-Tmid Date Time Expt. Ra Dec Mag
---------|---------------------|-------|-----------------|-----------------|-----
268 2020-07-16 23:01:45 50 (13h 04m 02.41s , +29d 38m 39.4s) 16.3
The 5-sigma upper limit has been about 16.6mag
The message may be cited.
GCN Circular 28124
Subject
GRB 200716C: Swift detection of a burst with an optical counterpart
Date
2020-07-16T23:10:50Z (5 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J.D. Gropp (PSU), N. J. Klingler (PSU),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:
At 22:57:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200716C (trigger=982707). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 196.013, +29.630 which is
RA(J2000) = 13h 04m 03s
Dec(J2000) = +29d 37' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 10 sec. The peak count rate
was ~30000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 22:59:04.2 UT, 82.9 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 196.0100, 29.6465 which is equivalent to:
RA(J2000) = 13h 04m 2.40s
Dec(J2000) = +29d 38' 47.4"
with an uncertainty of 6.6 arcseconds (radius, 90% containment). This
location is 60 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
The initial flux in the 0.1 s image was 1.10e-08 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 93 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 13:04:02.43 = 196.01011
DEC(J2000) = +29:38:40.6 = 29.64460
with a 90%-confidence error radius of about 0.75 arc sec. This position is 6.85
arc sec. from the center of the XRT error circle. The estimated magnitude is
16.34 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01.
Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular 28123
Subject
GRB 200716C: Fermi GBM Final Real-time Localization
Date
2020-07-16T23:08:03Z (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 22:57:41 UT on 16 Jul 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200716C (trigger 616633066.180458 / 200716957).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 192.1, Dec = 35.3 (J2000 degrees, equivalent to J2000 12h 48m, 35d 17'), with a statistical uncertainty of 2.3 degrees.
The angle from the Fermi LAT boresight is 36.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200716957/quicklook/glg_skymap_all_bn200716957.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/bn200716957/quicklook/glg_healpix_all_bn200716957.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200716957/quicklook/glg_lc_medres34_bn200716957.gif