Gamma-ray Burst 161023A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sun 23 Oct 16 22:38:58 UT
NOTICE_TYPE:    INTEGRAL Wakeup
TRIGGER_NUM:    7613,   Sub_Num: 0
GRB_RA:         310.9939d {+20h 43m 59s} (J2000),
                311.2866d {+20h 45m 09s} (current),
                310.1203d {+20h 40m 29s} (1950)
GRB_DEC:        -47.6810d {-47d 40' 51"} (J2000),
                -47.6194d {-47d 37' 09"} (current),
                -47.8620d {-47d 51' 42"} (1950)
GRB_ERROR:      3.28 [arcmin, radius, statistical only]
GRB_INTEN:      8.09 [sigma]
GRB_TIME:       81531.10 SOD {22:38:51.10} UT
GRB_DATE:       17684 TJD;   297 DOY;   16/10/23
SC_RA:          299.50 [deg] (J2000)
SC_DEC:         -39.91 [deg] (J2000)
SUN_POSTN:      208.82d {+13h 55m 18s}  -11.81d {-11d 48' 17"}
SUN_DIST:        89.50 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:     136.62d {+09h 06m 28s}  +14.06d {+14d 03' 45"}
MOON_DIST:      146.15 [deg]
GAL_COORDS:     352.09,-38.29 [deg] galactic lon,lat of the burst
ECL_COORDS:     300.15,-28.44 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=10.0000 and Time_Error=10.0000.  
COMMENTS:       Possibly real GRB event

red DSS finding chart ps-file

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sun 23 Oct 16 22:39:06 UT
NOTICE_TYPE:    INTEGRAL Refined
TRIGGER_NUM:    7613,   Sub_Num: 1
GRB_RA:         311.0512d {+20h 44m 12s} (J2000),
                311.3438d {+20h 45m 23s} (current),
                310.1778d {+20h 40m 43s} (1950)
GRB_DEC:        -47.6790d {-47d 40' 43"} (J2000),
                -47.6173d {-47d 37' 01"} (current),
                -47.8602d {-47d 51' 36"} (1950)
GRB_ERROR:      2.72 [arcmin, radius, statistical only]
GRB_INTEN:      16.23 [sigma]
GRB_TIME:       81539.10 SOD {22:38:59.10} UT
GRB_DATE:       17684 TJD;   297 DOY;   16/10/23
SC_RA:          299.50 [deg] (J2000)
SC_DEC:         -39.91 [deg] (J2000)
SUN_POSTN:      208.82d {+13h 55m 18s}  -11.81d {-11d 48' 17"}
SUN_DIST:        89.54 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:     136.62d {+09h 06m 28s}  +14.06d {+14d 03' 44"}
MOON_DIST:      146.16 [deg]
GAL_COORDS:     352.09,-38.33 [deg] galactic lon,lat of the burst
ECL_COORDS:     300.19,-28.45 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=10.0000 and Time_Error=10.0000.  
COMMENTS:       Possibly real GRB event

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sun 23 Oct 16 22:41:57 UT
NOTICE_TYPE:    INTEGRAL Refined
TRIGGER_NUM:    7613,   Sub_Num: 2
GRB_RA:         311.0404d {+20h 44m 10s} (J2000),
                311.3331d {+20h 45m 20s} (current),
                310.1670d {+20h 40m 40s} (1950)
GRB_DEC:        -47.6815d {-47d 40' 53"} (J2000),
                -47.6199d {-47d 37' 11"} (current),
                -47.8627d {-47d 51' 45"} (1950)
GRB_ERROR:      2.60 [arcmin, radius, statistical only]
GRB_INTEN:      22.82 [sigma]
GRB_TIME:       81581.10 SOD {22:39:41.10} UT
GRB_DATE:       17684 TJD;   297 DOY;   16/10/23
SC_RA:          299.50 [deg] (J2000)
SC_DEC:         -39.91 [deg] (J2000)
SUN_POSTN:      208.83d {+13h 55m 18s}  -11.81d {-11d 48' 20"}
SUN_DIST:        89.53 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:     136.64d {+09h 06m 35s}  +14.06d {+14d 03' 24"}
MOON_DIST:      146.15 [deg]
GAL_COORDS:     352.09,-38.33 [deg] galactic lon,lat of the burst
ECL_COORDS:     300.18,-28.45 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=40.0000 and Time_Error=40.0000.  
COMMENTS:       Possibly real GRB event

GCN Circular #20102
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 NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sun 23 Oct 16 23:25:38 UT
NOTICE_TYPE:    INTEGRAL Offline
TRIGGER_NUM:    7613,   Sub_Num: 3
GRB_RA:         311.0342d {+20h 44m 08s} (J2000),
                311.3268d {+20h 45m 18s} (current),
                310.1609d {+20h 40m 39s} (1950)
GRB_DEC:        -47.6613d {-47d 39' 40"} (J2000),
                -47.5997d {-47d 35' 58"} (current),
                -47.8425d {-47d 50' 32"} (1950)
GRB_ERROR:      2.60 [arcmin, radius, statistical only]
GRB_INTEN:      22.82 [sigma]
GRB_TIME:       81581.10 SOD {22:39:41.10} UT
GRB_DATE:       17684 TJD;   297 DOY;   16/10/23
SC_RA:          299.50 [deg] (J2000)
SC_DEC:         -39.91 [deg] (J2000)
SUN_POSTN:      208.86d {+13h 55m 25s}  -11.82d {-11d 48' 58"}
SUN_DIST:        89.50 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:     137.04d {+09h 08m 10s}  +13.97d {+13d 58' 25"}
MOON_DIST:      146.04 [deg]
GAL_COORDS:     352.11,-38.32 [deg] galactic lon,lat of the burst
ECL_COORDS:     300.19,-28.43 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=40.0000 and Time_Error=40.0000.  
COMMENTS:       refined_coordinates_after_offline_analysis

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sun 23 Oct 16 23:28:20 UT
NOTICE_TYPE:    INTEGRAL Offline
TRIGGER_NUM:    7613,   Sub_Num: 3
GRB_RA:         311.0342d {+20h 44m 08s} (J2000),
                311.3268d {+20h 45m 18s} (current),
                310.1609d {+20h 40m 39s} (1950)
GRB_DEC:        -47.6613d {-47d 39' 40"} (J2000),
                -47.5997d {-47d 35' 58"} (current),
                -47.8425d {-47d 50' 32"} (1950)
GRB_ERROR:      1.00 [arcmin, radius, statistical only]
GRB_INTEN:      22.82 [sigma]
GRB_TIME:       81581.10 SOD {22:39:41.10} UT
GRB_DATE:       17684 TJD;   297 DOY;   16/10/23
SC_RA:          299.50 [deg] (J2000)
SC_DEC:         -39.91 [deg] (J2000)
SUN_POSTN:      208.86d {+13h 55m 26s}  -11.82d {-11d 49' 00"}
SUN_DIST:        89.50 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:     137.07d {+09h 08m 16s}  +13.97d {+13d 58' 06"}
MOON_DIST:      146.03 [deg]
GAL_COORDS:     352.11,-38.32 [deg] galactic lon,lat of the burst
ECL_COORDS:     300.19,-28.43 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=40.0000 and Time_Error=40.0000.  
COMMENTS:       refined_coordinates_after_offline_analysis

GCN Circular #20103
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
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, in obtaining these observations.
GCN Circular #20106
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
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
tin-carrillo@ucd.ie>
A. Martin-Carrillo (UCD), D. Murphy (UCD), L. Hanlon (UCD), H. J. van Hee= rden (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=3D22:38:40 UT) when the source was just 21.9 degrees above the horiz= on. A series of 5 second exposures was taken in the SDSS r=E2=80=99 filte= r using an Andor EMCCD camera for the first 600 seconds, followed by 60 s= econd 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 co= nsistent 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=E2=80= =99) ~12.8, followed by a slow decay. On our last measurement at T0+893 s= econds, the source had faded to m(r=E2=80=99)~14.4.
Magnitudes were calibrated using several nearby APASS stars and are shown= in the Vega system. No correction for Galactic extinction in the directi= on of the GRB has been applied.
GCN Circular #20109
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
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
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=3D81552.321 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 =B1 0.6)x10^-5 erg/cm2 and a 64-ms peak energy flux, measured from T0-8.320, of (5.3 =B1 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 =3D -1.11 (-0.18,+0.22), the high energy photon index beta =3D -2.27 (-0.32,+0.16), the peak energy Ep =3D 163 (-28,+37) keV, chi2 =3D 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 =3D -0.55 (-0.28,+0.34), the high energy photon index beta =3D -2.16 (-0.24,+0.14), the peak energy Ep =3D 172 (-28,+43) keV, chi2 =3D 89/97 dof.
Assuming the redshift z=3D2.708 (Tanvir et al., GCN 20104) and a standard cosmology model with H_0 =3D 70 km/s/Mpc, Omega_M =3D 0.3, and Omega_Lambda =3D 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
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
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
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.

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Jochen Greiner, last update: 25-Oct-2016 [Disclaimer]