GRB 160709A
GCN Circular 19674
Subject
GRB 160709A: Tiled Swift observations
Date
2016-07-10T01:34:19Z (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 series of observations, tiled on the sky, of the
Fermi/LAT GRB 160709A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00057
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/LAT event is high: 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 19675
Subject
GRB 160709A: Fermi-LAT detection
Date
2016-07-10T01:58:47Z (9 years ago)
From
Sylvain Guiriec at UAH <sylvain.guiriec@lpta.in2p3.fr>
S. Guiriec (NASA GSFC/UMD/CRESST), G. Vianello (Stanford)
& J. Racusin (NASA GSFC)
report on behalf of the Fermi-LAT team:
At 19:49:03.50 on July, 09, 2016 Fermi-LAT detected high-energy
emission from GRB 160709A, which was also detected
by Fermi-GBM (trigger 489786546 / 160709826).
The best LAT on-ground location is found to be
RA, Dec = 236.110, -28.500 (J2000)
with an error radius of 0.18 deg (90 % containment, statistical error only).
This was 48 deg from the LAT boresight at the time of the trigger.
The data from the Fermi-LAT show a significant increase in the event rate
that is spatially and temporally correlated with the trigger with high
significance.
More than 30 photons above 100 MeV are observed within 100 seconds,
with the highest-energy photons being 1 GeV events observed 2 seconds
after the GBM trigger and consistent with the GBM brightest emission
episode.
A Swift ToO has been requested for this burst.
The Fermi-LAT point of contact for this burst is Sylvain Guiriec (
sylvain.guiriec@nasa.gov).
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 19676
Subject
GRB 160709A: Fermi GBM Observations
Date
2016-07-10T02:14:16Z (9 years ago)
From
Valerie Connaughton at USRA/NSSTC <valerie.connaughton@nasa.gov>
P. Jenke (UAH) reports on behalf of the Fermi GBM Team:
"At 19:49:03.50 UT on 09 July 2016, the Fermi Gamma-Ray Burst Monitor triggered and
located GRB 160709A (trigger 489786547 / 160709826), which was also detected by the LAT
(Guiriec et al. 2016, GCN 19675). The GBM on-ground location is consistent with the LAT position.
The angle from the Fermi LAT boresight at the GBM trigger time is 48 degrees.
The GBM light curve consists of two peaks with a duration (T90) of
about 5.6 s (50-300 keV) beginning 64 ms before the trigger time.
The time-averaged spectrum from T0-0.26 s to T0+0.83 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.43 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 2211 +/- 131 keV.
The event fluence (10-1000 keV) in this time interval is
(3.33 +/- 0.09)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.06 s in the 10-1000 keV band
is 6.5 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 19677
Subject
Konus-Wind observation of GRB 160709A (short/hard)
Date
2016-07-10T13:15:15Z (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 short/hard GRB 160709A
(Fermi-LAT detection: Guiriec, et al., GCN Circ. 19675;
Fermi-GBM detection: Jenke, GCN Circ. 19676)
triggered Konus-Wind at T0=71345.896 s UT (19:49:05.896).
The light curve shows a short, hard pulse with a total duration
of ~0.4 s. The emission is seen up to ~8 MeV.
As observed by Konus-Wind, the burst had a fluence of
(1.5 �� 0.3)x10^-5 erg/cm2 and a 16-ms peak energy flux,
measured from T0, of (6.3 �� 0.9)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).
The spectrum of the burst (measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 10 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.51(-0.17,+0.19),
and the peak energy Ep = 2554(-509,+664) keV,
chi2 = 40.1/50 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep with only an upper limit on beta of -2.1,
chi2 = 39.8/49 dof.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160709_T71345/
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
GCN Circular 19678
Subject
GRB 160709A: Global MASTER Net Fermi GBM Alerts observations
Date
2016-07-10T18:57:13Z (9 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, N.Tyurina, P.Balanutsa,
V.Kornilov, A.Kuznetsov, D.Kuvshinov,
Lomonosov Moscow State University, Sternberg Astronomical Institute
D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, 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, A.Gabovich, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
Ricardo Podesta, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in SAAO was pointed to the GRB160709.83 66 sec after notice time
and 105 sec after trigger time at 2016-07-09 19:50:49 UT. On our first
(20s exposure) set we no found OT within FERMI
error-box (ra=15 12 59 dec=-29 48 00 r=4.32) brighter then 18.8.
But this field do not included FERMI LAT error box (Guiriec et al., GCN
19675).
MASTER-SAAO robotic telescope located in SAAO was continue inspection of the GRB160709A and 1727 sec
after FERMI GBM
notice time (Jenke, GCN 19676) and before 9709 sec FERMI LAT notice time
and 1750 sec after trigger time at 2016-07-09 20:18:14 UT observed FERI
LAT error box. On our 120s exposure set we not found OT within FERMI LAT
error-box (Guiriec et al., GCN 19675) brighter then 19.6.
The message may be cited.
GCN Circular 19679
Subject
GRB 160709A: Swift-XRT observations
Date
2016-07-10T18:57:35Z (9 years ago)
From
Beatriz Mingo at U of Leicester,XRT <bm188@le.ac.uk>
T.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU),
B. Mingo (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
Fermi/LAT-detected burst GRB 160709A (Guiriec et al. GCN Circ. 19675)
in a series of observations tiled on the sky. The total exposure time
is 3.3 ks, distributed over 7 tiles; the maximum exposure at a single
sky location was 1.4 ks. The data were collected between T0+20.7 ks and
T0+39.1 ks, and are entirely in Photon Counting (PC) mode.
No uncatalogued X-ray sources have been detected. The 3-sigma upper
limit in the field (not including the regions where the tiles overlap)
ranges from ~0.01 to ~0.06 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 4.3e-13 to 2.2e-12 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).
Two previously-catalogued X-ray sources have been detected, however
their status as catalogued objects makes them unlikely to be the
afterglow.
The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00057.
This circular is an official product of the Swift-XRT team.
GCN Circular 19681
Subject
GRB 160709A, Swift-BAT detection and localization
Date
2016-07-11T23:01:33Z (9 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), J. P. Norris (BSU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
At 19:49:03.464 UT on 2016-07-09, BAT detected a count rate increase and
a sub-threshold signal in the image. Due to the sub-threshold nature, this event
did not trigger a normal burst event-by-event response. Using the data set from
T-2 to T+8 sec from the recent telemetry downlink, the ground analysis found
an 8.8 sigma detection in a 10-s image in 15-350 keV. As discussed below,
this is likely the same burst, GRB160709A, that was detected by Fermi/GBM
(Jenke et al. GCN Circ. 19676), Fermi/LAT (Guiriec et al. GCN Circ. 19675),
and Konus-Wind (Frederiks et al. GCN Circ. 19677).
The BAT ground-calculated position is RA, Dec = 235.996, -28.188 deg which is
RA(J2000) = 15h 43m 59.1s
Dec(J2000) = -28d 11' 18.2"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 19%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~T0
and peaks at ~T+0.8 s. The main pulses end at ~T+1 s, but there are some
weak emissions that continue beyond the event data range. T90 (15-350 keV)
estimated from the raw light curve is 4.8 +- 1.6 sec (estimated error including
systematics).
The time-averaged spectrum from T+0.0 to T+4.8 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.11 +- 0.28. The fluence in the 15-150 keV band is 4.5 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.30 sec in the 15-150 keV band
is 2.7 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
Using a 16-ms binned light curve, the lag of the initial pulse (~T0 to ~T+1 s)
for the 100-350 keV to 25-50 keV bands is 3 (+/-5) ms (with 1-sigma error).
Using a 4-ms binned light curve, the lag of the initial pulse for the same energy
bands is 6 (+/-5) ms. These values are consistent with those from a short GRB.
The detection time of this burst is only ~0.04 s from the Fermi/GBM trigger
time of GRB160709A (Jenke et al., GCN Circ. 19676). Also, the burst structure
is very similar to the one seen in the GBM. We thus believe the BAT detection
is highly likely to be GRB160709A.
However, we note that the BAT location is ~0.33 degrees from the LAT location
and outside of the reported LAT error circle of 0.18 deg (statistical error only;
Guiriec et al. GCN Circ. 19675). The large dispersion in the position
measurements may be explained by the unknown systematic uncertainty in the
LAT position. Nonetheless, we cannot rule out the possibility that these are
independent events.
The BAT location for this burst is covered by the XRT tiling search. No XRT or
UVOT afterglows are found within the BAT error circle.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/703769/BA/
GCN Circular 19682
Subject
GRB 160709A: MASTER early imaging Swift BAT error box
Date
2016-07-12T08:54:53Z (9 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, N.Tyurina, P.Balanutsa, V.Kornilov, A.Kuznetsov,
D.Kuvshinov,
Lomonosov Moscow State University, Sternberg Astronomical Institute
D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, 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, A.Gabovich, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
R.Podesta, C.Lopez and F.Podest
Observatorio Astronomico Felix Aguilar (OAFA)
H.Levato and C.Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
MASTER-SAAO robotic telescope (2x4 square
degrees twin telescope, http://observ.pereplet.ru) was pointing
to the Swift-BAT error box (Sakamoto et al., GCN 19681) during Fermi-GBM
alert inspection 1727 sec after FERMI GBM notice time (Jenke, GCN
19676) and before 9709 sec FERMI LAT notice time and 1750 sec after trigger
time at 2016-07-09 20:18:14 UT. On our 180s exposure set we not found OT
within Swift-BAT (Sakamoto et al., GCN 19681) brighter then 19.6.
The inspection and references images are available at
http://master.sai.msu.ru/static/GRB160709A_MASTER_SAAO.png .
The message may be cited.
GCN Circular 19701
Subject
GRB 160709A CALET Gamma-Ray Burst Monitor detection
Date
2016-07-14T06:57:55Z (9 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama,
Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU),
S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR),
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
The short-duration GRB 160709A (Guiriec, et al., GCN circ. 19675;
Jenke, et al., GCN circ. 19676; Frederiks, et al. GCN circ. 19677)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 19:49:04.67
on 9 July 2016. No real time CGBM GCN notice was distributed about
this trigger because the real time communication from the ISS was
off (loss of signal) between 19:42 and 20:04. The burst signal was
seen by all CGBM instruments.
The light curve of the SGM shows a single starting at T-0.2 sec,
peaking at T0-0.1 sec and ending at T+0.2 sec. The T90 duration
measured by the SGM data is 0.38 +- 0.04 sec (600-3000 keV).
The light curve is available at
http://cgbm.calet.jp/cgbm_trigger/flight/1152128868/
The CALET data used in this analysis are provided by the Waseda
CALET Operation Center located at the Waseda University.
GCN Circular 19740
Subject
GRB160709A: Astrosat CZTI detection of short GRB
Date
2016-07-29T04:24:51Z (9 years ago)
From
Varun Bhalerao at IUCAA <varunb@iucaa.in>
V. Bhalerao (IUCAA), V. Kumar (IUCAA), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
Analysis of Astrosat data showed the CZTI detection of a short GRB 160709A (Fermi-LAT detection: Guiriec, et al., GCN Circ. 19675).
The GRB occured at an angle of 124 degrees away from the CZTI pointing direction. The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak at 19:49:04.00 UT, 0.5 seconds after Fermi Trigger at 19:49:03.50 and a peak count rate of 1035.0 counts/sec above the background (four quadrants summed together), with a total of 3878.0 counts. The local mean background count rate was 314.0 counts/sec. Using cumulative rates, we measure a T90 of 0.45 sec, consistent with the Konus-Wind measurement of 0.4s (Frederiks et al., GCN Circ. 19677) and CALET (Asaoka et al., GCN Circ. 19701) but inconsistent with Swift-BAT (Sakamoto et al., GCN Circ. 19681) and Fermi (Jenke et al., GCN Circ. 19676).
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.