GRB 161023A
GCN Circular 20102
Subject
GRB 161023A (Integral trigger 7613) MASTER-Net bright OT detection
Date
2016-10-23T23:06:38Z (9 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
E. Gorbovskoy, V. Lipunov, N.Tyurina, V.Kornilov, P.Balanutsa,
A.Kuznetsov, D.Kuvshinov,
Lomonosov Moscow State University, Sternberg Astronomical Institute
D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik
Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A. Gabovich
Blagoveschensk Educational State University, Blagoveschensk
V.Krushinski, I.Zalozhnih, A. Popov
Ural Federal University, Kourovka
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in SAAO was pointed to the GRB161023.94 24 sec after notice time
and 33 sec after trigger time at 2016-10-23 22:39:24 UT in two
polarization.
On our first (10s exposure) and consequent images we found optical
bright transient within INTEGRAL error-box (ra=20 45 08 dec=-47 37 08
r=0.054667) at following position:
RA Dec
20h 44m 05.21s , -47d 39m 48s.5
OT rise up to maximum magnituge about 12.5 (~ 3 minutes after the
trigger).
The 5-sigma upper limit at first has been about 16.11mag
The message may be cited.
GCN Circular 20103
Subject
GRB 161023A: A long GRB detected by INTEGRAL
Date
2016-10-23T23:45:13Z (9 years ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro@iasf-milano.inaf.it>
S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno,
S.Fotopoulou(ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of
the IBAS Localization Team report:
a gamma ray burst lasting about 45 s has been detected by IBAS in the
IBIS/ISGRI data at 22:38:40 UT of 2016 October 23.
The refined coordinates (J2000) are:
R.A.= 311.0342 deg
DEC.= -47.6614 deg
with an uncertainty of 1 arcmin (90% c.l.).
The burst had a peak flux greater than 5 counts/cm2/s (20-200 keV, 1-s
integration time) and a fluence in the same energy range greater than 5e-6
erg/cmq. These are lower limits because this bright burst caused ISGRI
telemetry saturation.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 20104
Subject
GRB 161023A VLT/X-shooter redshift
Date
2016-10-24T03:17:06Z (9 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), T. Kruehler (MPE), A. De Cia (ESO),
K. Wiersema (U. Leicester), D. Xu (NAOC), D. Malesani (DARK/NBI),
report on behalf of a larger collaboration:
We observed the optical counterpart of the bright INTEGRAL
GRB 161023A (Mereghetti et al. GCN 20103; Gorbovskoy et al.
GCN 20102) with the ESO Very Large Telescope UT 2 (Kueyen)
equipped with the X-shooter spectrograph, covering the wavelength
range 3500-20000 AA. Observations started on October 24.05 UT
(approx 3.0 hr after the GRB) and consisted of 2 exposures of
600 s each.
The spectrum exhibits numerous absorption features including the
hydrogen Lyman series, and lines of SII, SiII, SiIV, CIV, AlII, FeII, OI,
several of which are fine structure lines, at a redshift of z=2.708. We
conclude this is the redshift of the GRB.
We acknowledge the generosity of the visiting observer, Chris D'Andrea,
who approved the override, and expert support from the ESO observing
staff, particularly Linda Schmidtobreick and Luca Sbordone, in obtaining
these observations.
[GCN OPS NOTE(24oct16): L.Sbordone was added to the last paragraph.]
GCN Circular 20106
Subject
GRB 161023A: Swift ToO observations
Date
2016-10-24T07:55:17Z (9 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 161023A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020709
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 20107
Subject
GRB 161023A: LCOGT-FTS optical observations
Date
2016-10-24T10:30:23Z (9 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), S. Kobayashi, I.A. Steele (LJMU), C.G. Mundell
(U. Bath), A. Gomboc (U. Nova Gorica) on behalf of a large collaboration
report:
The 2-m LCOGT Faulkes Telescope South began observing INTEGRAL GRB
161023A (Mereghetti et al., GCN 20103) in the SDSS ri filters on October
24, 09:17 UT (~0.44 days since the GRB). We clearly detect the optical
afterglow (Gorbovskoy et al. GCN 20102; Tanvir al. GCN 20104) at the
position RA(J2000)= 20:44:05.17, DEC(J2000)= -47:39:47.8 (error radius
of 1 arcsec) with the following values:
Mid time from GRB Exposure Filter Magnitude
(days) (s)
-------------------------------------------------------------
0.44 5x60 SDSS-R 18.57 +- 0.03
0.45 5x60 SDSS-I 18.38 +- 0.03
-------------------------------------------------------------
Calibration is done against nearby USNOB-1 star 20:44:08.421,
-47:39:34.63 assuming r=17.27, i=17.20 mag.
GCN Circular 20108
Subject
GRB 161023A: Watcher optical observations
Date
2016-10-24T14:27:48Z (9 years ago)
From
Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo@ucd.ie>
A. Martin-Carrillo (UCD), D. Murphy (UCD), L. Hanlon (UCD), H. J. van Heerden (UFS), B. van Soelen (UFS) and P. J. Meintjes (UFS)
We observed the field of GRB 161023A (Mereghetti et al, GCN 20103) using the 40cm UCD Watcher telescope at Boyden Observatory in South Africa.
Observations started at 22:39:23 UT, 43.7 seconds after the burst trigger (T0=22:38:40 UT) when the source was just 21.9 degrees above the horizon. A series of 5 second exposures was taken in the SDSS r��� filter using an Andor EMCCD camera for the first 600 seconds, followed by 60 second exposures until the source was below our observation limit at 22:53:33 UT (T0+893 seconds).
A bright transient source is clearly detected in all individual frames consistent with the location reported by Gorbovskoy et al. (GCN 20102). The source shows a fast rise up to ~T0+200 seconds where it peaks at m(r���) ~12.8, followed by a slow decay. On our last measurement at T0+893 seconds, the source had faded to m(r���)~14.4.
Magnitudes were calibrated using several nearby APASS stars and are shown in the Vega system. No correction for Galactic extinction in the direction of the GRB has been applied.
GCN Circular 20109
Subject
GRB 161023A: Zadko observatory - Gingin optical observations
Date
2016-10-24T14:28:37Z (9 years ago)
From
Alain Klotz at IRAP-CNRS-OMP <Alain.Klotz@free.fr>
Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.),
Coward, D. McPherson, D. Williams A., Martin R.,
Moore J., Dodson R. (UWA) report:
report:
We imaged the field of GRB 161023A detected by Integral
(trigger 7613, Mereghetti et al., GCN 20103)
with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia.
The observations started 0.55 day after the GRB trigger.
The elevation of the field decreased from
72 degrees above horizon and weather conditions
were good.
We detected the candidate couterpart mentioned by Gorbovskoy
et al. (GCNC 20102) and Tanvir al. (GCN 20104). We used the same
calibration star than Guidorzi et al. (GCNC 20107):
t0+0.55d to t0+0.63d : R = 19.09 +/- 0.05
Magnitudes are not corrected for galactic dust extinction.
GCN Circular 20110
Subject
GRB 161023A: TAROT La Silla observatory optical observations
Date
2016-10-24T14:52:46Z (9 years ago)
From
Alain Klotz at IRAP-CNRS-OMP <Alain.Klotz@free.fr>
Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:
We imaged the field of GRB 161023A detected by Integral
(trigger 7613, Mereghetti et al., GCN 20103)
with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.
The observations started 64 min after the GRB trigger
(just after the dusk).
The elevation of the field decreased from
71 degrees above horizon and weather conditions
were cloudy so only few images can be measured.
We detected the couterpart mentioned by Gorbovskoy
et al. (GCNC 20102) and Tanvir al. (GCN 20104).
t0 +64 min to t0 +87 min : R = 15.2 +/-0.2
t0 +96 min to t0+116 min : R = 15.8 +/-0.4
t0+143 min to t0+149 min : Rlim = 15.8
Magnitudes were estimated with the nearby star
NOMAD-1 0423-1044399 ra=311.0274867 dec=-47.6493169
R=12.37.
Magnitudes are not corrected for galactic dust extinction.
GCN Circular 20111
Subject
Konus-Wind observation of GRB 161023A
Date
2016-10-24T17:04:57Z (9 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 161023A (INTEGRAL detection: Mereghetti et al., GCN 20103)
triggered Konus-Wind at T0=81552.321 s UT (22:39:12.321).
The light curve shows a broad emission pulse with a duration
of ~50 s. The emission is seen up to ~6 MeV.
As observed by Konus-Wind, the burst had a fluence of
(4.2 �� 0.6)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0-8.320, of (5.3 �� 0.8)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+24.832 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 = -1.11 (-0.18,+0.22),
the high energy photon index beta = -2.27 (-0.32,+0.16),
the peak energy Ep = 163 (-28,+37) keV,
chi2 = 81/97 dof.
The spectrum near the peak count rate (measured from T0 to T0+8.448 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 = -0.55 (-0.28,+0.34),
the high energy photon index beta = -2.16 (-0.24,+0.14),
the peak energy Ep = 172 (-28,+43) keV,
chi2 = 89/97 dof.
Assuming the redshift z=2.708 (Tanvir et al., GCN 20104)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.3, and Omega_Lambda = 0.7,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~6.8x10^53 erg,
the peak luminosity L_iso is ~3.2x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~640 keV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB161023_T81552/
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
GCN Circular 20112
Subject
GRB 161023A: Swift-XRT afterglow detection
Date
2016-10-24T17:39:57Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A. D'Ai (INAF-IASFPA), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows
(PSU), T.G.R. Roegiers (PSU), K.L. Page (U. Leicester), B. Mingo (U.
Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), P.
D'Avanzo (INAF-OAB) 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 161023A (Gorbovskoy et al. GCN Circ. 20102), collecting 1.1
ks of Photon Counting (PC) mode data between T0+34.8 ks and T0+53.2 ks.
A fading, uncatalogued X-ray source is detected consistent with the
MASTER position (Gorbovskoy et al., GCN Circ. 20102) and is therefore
believed to be the afterglow. Using 3643 s of PC mode data and 4 UVOT
images, we find an enhanced XRT position (using the XRT-UVOT alignment
and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
311.02161, -47.66348 which is equivalent to:
RA (J2000): 20h 44m 05.19s
Dec(J2000): -47d 39' 48.5"
with an uncertainty of 1.5 arcsec (radius, 90% confidence). This
position is 0.2 arcsec from the MASTER position.
The light curve can be modelled with a power-law decay with a decay
index of alpha=2.3 (+0.9, -1.0).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.09 (+0.30, -0.16). The
best-fitting absorption column is consistent with the Galactic value
of 3.2 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 3.1 x 10^-11 (3.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.2 (+/-5.6) x 10^20 cm^-2
Galactic foreground: 3.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 2.09 (+0.30, -0.16)
If the light curve continues to decay with a power-law decay index of
2.3, the count rate at T+24 hours will be 9.2 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x
10^-13 (3.1 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/00020709.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020709.
This circular is an official product of the Swift-XRT team.
GCN Circular 20113
Subject
GRB 161023A: GROND Observations
Date
2016-10-25T06:37:38Z (9 years ago)
From
Thomas Kruehler at MPE Garching <kruehler@mpe.mpg.de>
T. Kruehler and J. Greiner (both MPE Garching) report on behalf
of the GROND team:
We observed the field of GRB 161023A (INTEGRAL trigger 7613;
Mereghetti et al., GCN #20103) simultaneously in g'r'i'z'JHK with
GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG
telescope at the ESO La Silla Observatory (Chile).
Observations started at 23:52 UT on 2016-10-24, 25.2 hr after the GRB
trigger. They were performed at an average seeing of 1".6, and at an
average airmass of 1.1.
Based on combined images with 9.7 min of total exposures in g'r'i'z'
and 10.0 min in JHK at a mid-time of 00:12 UT on 2016-10-25,
we derive the following preliminary magnitudes (all in AB system) for
the optical/NIR afterglow (Gorbovskoy et al. GCN 20102, Tanvir et al.,
GCN 20104, Guidorzi et al., GCN 20107).
g' = 19.7 +- 0.1 mag
r' = 19.4 +- 0.1 mag
i' = 19.2 +- 0.1 mag
z' = 19.1 +- 0.1 mag
J = 18.7 +- 0.1 mag
H = 18.4 +- 0.1 mag
K = 18.2 +- 0.1 mag
Given magnitudes are calibrated against GROND zeropoints as well as
2MASS field stars and are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of E_(B-V) = 0.03 mag
in the direction of the burst (Schlafly & Finkbeiner 2011).
GCN Circular 20114
Subject
GRB161023A: AstroSat CZTI detection
Date
2016-10-25T07:05:27Z (9 years ago)
From
Varun Bhalerao at IUCAA <varunb@iucaa.in>
V. Sharma, V. Kumar, D. Bhattacharya and V. Bhalerao (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed clear detection of a long duration GRB161023A (INTEGRAL detection: Sandro Mereghetti et al., GCN Circ. 20103) in the 40-200 keV energy range. The light curve shows a single peak at 22:39:10.00 UT, 30 seconds after the INTREGAL trigger at 22:38:40 UT. The measured peak count rate is 132.10 counts/sec above the background in combined data of four quadrants, with a total of 2846 counts. The local mean background count rate was 367.10 counts/sec. Using cumulative rates, we measure a T90 of 44 sec.
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.