LIGO/Virgo S190706ai

IceCube Collaboration (http://icecube.wisc.edu/) reports:

Searches [1,2] for track-like muon neutrino events detected by IceCube
consistent with the sky localization of gravitational-wave candidate S190706ai
 in a time range of 1000 seconds [3] centered on the alert event time
(2019-07-06 22:18:21.345 UTC to 2019-07-06 22:35:01.345 UTC) have been performed.  During this time
period IceCube was collecting good quality data.  No significant track-like
events are found in spatial coincidence of S190706ai calculated from the map
circulated in the 1-Preliminary notice.

IceCube's sensitivity assuming an E^-2 spectrum (E^2 dN/dE) to neutrino
point sources within the locations spanned by the 90% spatial  containment
of S190706ai ranges from  0.035 to 0.881 GeV cm^-2 in a 1000 second
time window.

The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector
operating at the geographic South Pole, Antarctica. The IceCube realtime
alert point of contact can be reached at roc@icecube.wisc.edu<mailto:roc@icecube.wisc.edu>


[1] Bartos et al. arXiv:1810.11467
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  (2018) and Countryman et al.arXiv:1901.05486
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  (2019)
[2] Braun et al., Astroparticle Physics 29, 299 (2008)
[3] Baret et al., Astroparticle Physics 35, 1 (2011)

The LIGO Scientific Collaboration and the Virgo Collaboration report:


We identified the compact binary merger candidate S190706ai during
real-time processing of data from LIGO Hanford Observatory (H1), LIGO
Livingston Observatory (L1), and Virgo Observatory (V1) at 2019-07-06
22:26:41.345 UTC (GPS time: 1246487219.345). The candidate was found
by the PyCBC Live [1], CWB [2], GstLAL [3], MBTAOnline [4], and SPIIR
[5] analysis pipelines.

S190706ai is an event of interest because its false alarm rate, as
estimated by the online analysis, is 1.9e-09 Hz, or about one in 16
years. The event's properties can be found at this URL:

https://gracedb.ligo.org/superevents/S190706ai

The classification of the GW signal, in order of descending
probability, is BBH (99%), Terrestrial (1%), BNS (<1%), NSBH (<1%), or
MassGap (<1%).

Assuming the candidate is astrophysical in origin, there is strong
evidence against the lighter compact object having a mass < 3 solar
masses (HasNS: <1%). Using the masses and spins inferred from the
signal, there is strong evidence against matter outside the final
compact object (HasRemnant: <1%).

One sky map is available at this time and can be retrieved from the
GraceDB event page:
 * bayestar.fits.gz, an updated localization generated by BAYESTAR
[6], distributed via GCN notice about 17 minutes after the candidate

For the bayestar.fits.gz sky map, the 90% credible region is 1100
deg2. Marginalized over the whole sky, the a posteriori luminosity
distance estimate is 5725 +/- 1446 Mpc (a posteriori mean +/- standard
deviation).

For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.

 [1] Nitz et al. PRD 98, 024050 (2018)
 [2] Klimenko et al. PRD 93, 042004 (2016)
 [3] Messick et al. PRD 95, 042001 (2017)
 [4] Adams et al. CQG 33, 175012 (2016)
 [5] Qi Chu, PhD Thesis, The University of Western Australia (2017)
 [6] Singer & Price PRD 93, 024013 (2016)

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov 
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias)

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev, O.Ershova 
(Irkutsk State University, API),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich, Yu. Sergienko 
(Blagoveschensk Educational State University)




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) started inspect of the LIGO/Virgo S190706ai errorbox  1152 sec after trigger time at 2019-07-06 22:45:53 UT, with upper limit up to  18.7 mag. The observations began at zenit distance = 107 deg. The sun  altitude  is -28.9 deg. 

The galactic latitude b = -60 deg., longitude l = 98 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/ligo_1.php?id=10450

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    1242 | 2019-07-06 22:45:53 |          MASTER-IAC | ( 12h  3m 31.75s , +55d 17m 03.03s) |  P| |   180 | 18.7 |        
    1242 | 2019-07-06 22:45:53 |          MASTER-IAC | ( 12h  2m 12.80s , +55d 21m 21.28s) |  P- |   180 | 18.7 |        


The observation and reduction will continue. 
The message may be cited.

F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ.
Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), F.
Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, N. Parmiggiani
(INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN
Trieste), report on behalf of the AGILE Team:

In response to the LIGO/Virgo GW event S190706ai at T0 = 2019-07-06 22:26:41.345 (UT),
a preliminary analysis of the AGILE minicalorimeter (MCAL) triggered data found no
event candidates within a time interval covering +/- 15 s from the LIGO/Virgo T0.

At the T0, about 54% of the S190706ai 90% c.l. localization region was accessible
to the AGILE MCAL. Three-sigma upper limits (ULs) are obtained for a 1 s integration
time at different celestial positions within the accessible S190706ai localization
region, from a minimum of 1.6E-06 erg cm^-2 to a maximum of 2.2E-06 erg cm^-2
(assuming as spectral model a single power law with photon index 1.5).

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.

H. Negoro (Nihon U.), N. Kawai, M. Sugizaki (Tokyo Tech), 
S. Sugita, M. Serino (AGU), 
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), 
S. Nakahira, T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN), 
T. Sakamoto, H. Nishida, A. Yoshida (AGU), 
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), 
M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech), 
S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai, M. Tominaga (JAXA), 
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), 
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), 
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.), 
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU) 
report on behalf of the MAXI team: 

We examined MAXI/GSC all-sky X-ray images (2-20 keV) 
after the LVC trigger S190706ai at 2019-07-06 22:26:41.344 UTC (GCN 24998
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 ). 

At the trigger time of S190706ai, the high-voltage of MAXI/GSC was off, 
and it was turned on at T0+730 sec (+12.1 min). 
The first one-orbit (92 min) scan observation with GSC after the event covered 66% 
of the 90% credible region of the bayestar skymap from 22:39:0 to 23:58:30 UTC (T0+739 to T0+5509 sec). 

No significant new source was found in the region in the one-orbit scan observation. 
A typical 1-sigma averaged upper limit obtained in one scan observation 
is 20 mCrab at 2-20 keV. 

If you require information about X-ray flux by MAXI/GSC at specific coordinates, 
please contact the submitter of this circular by email.

The HAWC Collaboration (https://www.hawc-observatory.org) reports:

The HAWC Collaboration performed a follow-up of the gravitational wave
trigger S190706ai (GCN #24998
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 ). At the time of the trigger the HAWC
local zenith was oriented towards (RA, Dec) = (163.7 deg, 19.1 deg).
62% of the GW candidate sky location probability fell within our
observable field of view (0-45 deg zenith angle).

We performed a search for a short timescale emission using 6 sliding
time windows (dt = 0.3s, 1s, 3s, 10s, 30s and  100s), shifted forward
in time by 20% of their width. We searched the 95% probability
containment area in a timescale-dependent time period, from t0-5dt to
t0+10dt, where t0 is the time of the GW trigger.

No significant gamma-ray detection above the background was observed.

The sensitivity of this analysis is greatly dependent on zenith angle,
ranging from 10.8 deg to 45 deg for the area searched in this
analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the
80-800GeV energy range goes from 1.6e-6 erg/cm^2 to 1.1e-4 erg/cm^2
(7.5e-6 erg/cm^2 to 5.0e-4 erg/cm^2), depending on the zenith
angle.

HAWC is a TeV gamma ray water Cherenkov array located in the state of
Puebla, Mexico. It is sensitive to the energy range ~0.1-100TeV, and
monitors 2/3 of the sky every day with an instantaneous field-of-view
of ~2 sr.

F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ.
Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), F.
Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, N. Parmiggiani
(INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN
Trieste), report on behalf of the AGILE Team:

In response to the LIGO/Virgo GW event S190706ai at T0 = 2019-07-06 22:26:41.345 (UT)
(GCN #24998
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 ), we performed an analysis of the AGILE Gamma-Ray Imaging Detector (GRID)
data.

At the LIGO/Virgo trigger time (T0), the GRID exposure covered nearly 54% of the
90% c.l. localization region (LR), observed at off-axis angles between 30 and 50 deg.

An analysis of the data in the energy range 50 MeV - 10 GeV was performed between
different time intervals and time integrations near T0. Preliminary values of 3-sigma
upper limits (UL) obtained within the accessible LIGO/Virgo 90% c.l. LR are:

(T0-2s; T0+2s): from 9.4e-07 to 2.4e-06 erg cm^-2 s^-1;

(T0; T0+10s): from 3.4e-07 to 8.9e-07 erg cm^-2 s^-1;

(T0; T0+100s): from 3.6e-08 to 2.7e-07 erg cm^-2 s^-1;

These measurements were obtained with AGILE observing a large portion of the
sky in spinning mode. Additional analysis of AGILE data is in progress.

M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration:

Using on-line data from the ANTARES detector, we have performed a follow-up analysis of the
recently reported LIGO/Virgo S190706ai event using the 90% contour of the bayestar probability
map provided by the GW interferometers (GCN #24998
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  <https://gcn.gsfc.nasa.gov/gcn3/24998.gcn3
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 >). The ANTARES visibility at the time of the
alert, together with the 50% and 90% contours of the probability map are shown at http://antares.in2p3.fr/GW/S190706ai.png <http://antares.in2p3.fr/GW/S190706ai.png>.
Considering the location probability provided by the LIGO/Virgo collaborations, there is a
48.7% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of the alert.

No up-going muon neutrino candidate events were recorded in the ANTARES sky during a
+/-500s time-window centered on the time 2019-07-06 22:26:41 and in the 90% contour of the S190706ai
event. The expected number of atmospheric background events in the region visible by ANTARES is
3.63e-04 in the +/- 500s time window. An extended search during +/- 1 hour gives no
up-going muon neutrino coincidence. The expected number of atmospheric background events in the
region visible by ANTARES is 2.62e-03 in this larger time window.

ANTARES <http://antares.in2p3.fr/> is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is
primarily sensitive to neutrinos in the TeV-PeV  energy range. At 10 TeV, the median angular
resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a
competitive sensitivity to this position in the sky.

Celia Sanchez-Fernandez (ESA ESAC, Madrid), James Rodi (IAPS-Roma, Italy)
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
A. Coleiro (APC, France)
S. Mereghetti (INAF IASF-Milano, Italy)

on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration

Using combination of INTEGRAL all-sky detectors (following [1]):
SPI/ACS, IBIS/Veto, and IBIS we have performed a search for a prompt
gamma-ray counterpart of S190706ai (GCN 24998
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 ).

At the time of the event (2019-07-06 22:26:41 UTC, hereafter T0),
INTEGRAL was operating in nominal mode. The peak of the event
localization probability was at an angle of 65 deg with respect to the
spacecraft pointing axis. This orientation implies strongly suppressed
(19% of optimal) response of ISGRI, somewhat suppressed (40% of
optimal) response of IBIS/Veto, and near-optimal (98% of optimal)
response of SPI-ACS.

The background within +/-300 seconds around the event was very stable
(excess variance 1.2).

We have performed a search for any impulsive events in INTEGRAL SPI-
ACS (as described in [2]), IBIS, and IBIS/Veto data.

We do not detect any significant counterparts and estimate a 3-sigma
upper limit on the 75-2000 keV fluence of 1.7e-07 erg/cm^2 (within the
50% probability containement region of the source localization) for a
burst lasting less than 1 s with a characteristic short GRB spectrum
(an exponentially cut off power law with alpha=-0.5 and Ep=600 keV)
occurring at any time in the interval within 300 s around T0. For a
typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and
Ep=300 keV), the derived peak flux upper limit is ~1.5e-07 (5.4e-08)
erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.

For the mean reported distance 5725.0 Mpc this corresponds to the
limit on the total isotropic equivalent energy in 1 s of 6.8e+50 erg
for the short GRB spectrum and for a long GRB spectrum isotropic
equivalent luminosity in 1 s (8 s) of 5.8e+50 erg/s (2.1e+50 erg/s)



All results quoted are preliminary.

This circular is an official product of the INTEGRAL Multi-Messenger
team.

[1] Savchenko et al. 2017, A&A 603, A46
[2] Savchenko et al. 2012, A&A 541A, 122S

R. Hamburg (UAH) reports on behalf of the Fermi-GBM Team and the
GBM-LIGO/Virgo group:

For the LIGO/Virgo detection of GW trigger S190706ai (GCN 24998
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 ) and using
the initial BAYESTAR skymap, Fermi-GBM was observing 62.0% of the
localization probability at
event time.

There was no Fermi-GBM onboard trigger around the event time of S190706ai.
An
automated, blind search for short gamma-ray bursts below the onboard
triggering
threshold in Fermi-GBM also identified no counterpart candidates. The GBM
targeted
search, the most sensitive, coherent search for GRB-like signals, was run
from +/- 30 s
around merger time, and also identified no counterpart candidates.

Part of the LVC localization region is behind the Earth for Fermi, located
at RA = 170.4
and Dec = -20.2 with a radius of 67.5 degrees. We therefore set upper
limits on
impulsive gamma-ray emission. Using the representative soft, normal, and
hard GRB-like templates described in arXiv:1612.02395
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 , we set the following
3 sigma flux upper limits
over 10-1000 keV, weighted by GW localization probability, (in units of
10^-7
erg/s/cm^2):

Timescale  Soft    Normal    Hard
--------------------------------------
0.1 s:      5.7     7.5      13.
1.0 s:      1.5     2.2      3.9
10. s:      0.5     0.5      0.9

Assuming the median luminosity distance of 5725 Mpc (z=0.881) from the GW
detection,
we estimate the following intrinsic luminosity upper limits over the 1
keV-10 MeV energy
range (in units of 10^51 erg/s):

Timescale  Soft   Normal   Hard
------------------------------------
0.1 s:     3.6     4.0     11.7
1.0 s:     1.0     1.2      3.5
10  s:     0.3     0.3      0.8

M. Axelsson (KTH and Stockholm Univ.),
E. Bissaldi (Politecnico and INFN Bari) and
F. Longo (University and INFN, Trieste)
report on behalf of the Fermi-LAT Collaboration:


"We have searched data collected by the Fermi Large Area Telescope (LAT)
on July 6, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission
in spatial/temporal coincidence with the LIGO/Virgo trigger S190706ai (GCN 24998
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 ).

We define "instantaneous coverage" as the integral over the region
of the LIGO probability map that is within the LAT field of view
at a given a time, and "cumulative coverage" as the integral
of the instantaneous coverage over time.
Fermi-LAT had instantaneous coverage of 45% of the LIGO probability
region at the time of the trigger (T0 = 2019-07-06 22:26:41.345 UTC),
and reached full coverage at T0+1 ks.

We performed a search for a transient counterpart
within the observed region of the 90% contour of the LIGO map
in a fixed time window from T0 to T0+10 ks.
No significant sources were found.
We also performed a search which adapted the time interval of the analysis
to the exposure of each region of the sky,
and no additional excesses were found.

Energy flux upper bounds for the fixed time interval
between 100 MeV and 1 GeV for this search vary
between 2e-10 and 5e-09 [erg/cm^2/s].

The Fermi-LAT point of contact for this event is
Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it)."


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.

S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
A. A. Breeveld (MSSL-UCL), A. P. Beardmore (U. Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASI-SSDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU), H. A. Krimm (NSF),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), J. A. Nousek (PSU),
S. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU),
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:

We report the search results in the BAT data within T0 �� 100 s of the
LVC event S190706ai (LIGO/VIRGO Collaboration GCN Circ. 24998
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 ),
where T0 is the LVC trigger time (2019-07-06T22:26:41.344 UTC).

The center of the BAT FOV at T0 is
RA = 107.468 deg,
DEC = -29.539 deg,
ROLL = 357.582 deg.
The BAT Field of View (>10% partial coding) covers 0.41% of the integrated
LVC localization probability, and 1.84% of the galaxy convolved
probability (Evans et al. 2016).

Within T0 �� 100 s, no significant detections (signal-to-noise ratio
> ~ 5 sigma) are found in the BAT raw light curves with time bins of 64 ms, 
1 s, and 1.6 s. Assuming an on-axis (100% coded) short GRB with a typical
spectrum in the BAT energy range (i.e., a simple power-law model with a
power-law index of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma upper
limit in the 1-s binned light curve corresponds to a flux upper
limit (15-350 keV) of ~ 7.91 x 10^-8 erg/s/cm^2.

Event data are available from T0+29.4 s to T0+32.6 s. No significant
detections are found in the 15-350 keV images made using T0+29.4 s
and T0+32.6 s.

BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 68.12% of the integrated LVC
localization probability was outside of the BAT FOV but above the
Earth's limb from Swift's location, and the corresponding flux upper limits
for this region are within roughly an order of magnitude higher than those
within the FOV.

The results of the BAT analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S190706ai/web/source.html

P. S. Marrocchesi (U of Siena), A. Yoshida, T. Sakamoto, V. Pal'shin,
S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), 
S. Nakahira (RIKEN), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
and the CALET collaboration:


At the trigger time of the compact binary merger candidate S190706ai,
T0 = 2019-07-06 22:26:41.345 UT (The LIGO Scientific Collaboration 
and Virgo Collaboration, GCN Circ. 24998
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 ), the CALET Gamma-ray 
Burst Monitor (CGBM) high voltages were off (from T0-15 min to 
T0+12 min).

The CALET Calorimeter (CAL) was operating in the high energy
trigger mode at the trigger time of S190706ai, but the CAL FOV 
does not have any overlap with the LVC high probability localization 
region.  The CAL FOV was centered at RA= 210.4 deg, DEC = -45.4 deg
at T0.

Shaunak Modak, Yukei Murakami, Andrew Hoffman, Thomas de Jaeger,
Sergiy Vasylyev, Benjamin Stahl, Keto Zhang, WeiKang Zheng,
Nachiket Girish, and Alexei V. Filippenko (UC Berkeley) report
on behalf of the Lick/KAIT GW follow-up team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, observed the 90% region of the gravitational-wavei
event S190706ai (GCN 24998
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 ) detected by LIGO/Virgo. More than one
thousand galaxies were selected from the Glade catalog V1.0 (Dalya et al.,
2018, MNRAS, 479, 2374; http://aquarius.elte.hu/glade/)
according to their priority score. KAIT observed 129 of them based on
their priority scores and elevation visibility, with each clear-filter
exposure time being 60 s. The first image was taken at 04:22:48, July
7th UT, about 5.9 hours after the trigger, and the last image at 07:18:41
UT.
Our typical limiting mag is 19.0. No viable counterparts were identified
and the analysis is ongoing. A full list of galaxies observed by KAIT
is given below.

GladeID   UT(July07)  RA_J2000   Dec_J2000
-----------------------------------------------
G0777412  04:22:48  12:13:30.498   +61:02:32.7372
G0571516  04:23:57  12:14:48.589   +59:54:21.9384
G0564638  04:25:06  12:16:06.599   +60:35:13.2072
G0904927  04:26:16  12:17:20.5774  +60:52:59.4984
G0787109  04:27:25  12:17:49.7863  +61:29:39.5808
G1199777  04:28:34  12:19:32.0654  +62:09:19.7676
G0732275  04:29:44  12:20:24.5472  +61:05:59.9388
G0698214  04:30:53  12:20:54.5875  +61:59:34.9656
G0565645  04:32:11  12:22:30.8093  +63:54:11.2788
G0682903  04:33:20  12:23:01.0913  +61:42:26.2044
G0765680  04:34:29  12:23:05.2368  +63:13:21.1764
G1908371  04:35:39  12:23:42.9859  +62:56:25.4904
G0790650  04:36:48  12:24:08.4082  +63:38:49.7184
G1709689  04:38:03  12:24:12.24    +58:50:13.308
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G1097215  07:18:41  16:09:06.4855  +60:52:14.1672

The LIGO Scientific Collaboration and the Virgo Collaboration report:

We have conducted further analysis of the LIGO and Virgo data around
the time of the compact binary coalescence (CBC) candidate S190706ai
(GCN 24998
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 ). Parameter estimation has been performed using
LALInference [1] and a new sky map, LALInference.offline.fits.gz,
distributed via GCN Notice, is available for retrieval from the
GraceDB event page:

https://gracedb.ligo.org/superevents/S190706ai

LALInference.offline.fits.gz is the preferred sky map at this time.
The 90% credible region is 826 deg2. Marginalized over the whole sky,
the a posteriori luminosity distance estimate is 5263 � 1402 Mpc
(a posteriori mean � standard deviation).

For further information about analysis methodology and the contents
of this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https/emfollow.docs.ligo.org/userguide/>.

[1] Veitch et al. PRD 91, 042003 (2015)

Y. G. Zheng, C. Cai, S. Xiao, Q. B. Yi, Q. Luo, C. K. Li, 
X. B. Li, G. 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: 

Insight-HXMT was taking data normally around the reported LIGO/Virgo 
S190706ai event (GCN #24998
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 ), trigger time 2019-07-06T22:26:41.344 UTC. 
At T0, about 64% of the LIGO localization region was covered by the 
Insight-HXMT without occultationby the Earth.

Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are 
found in a search of the Insight-HXMT/HE raw light curves.

Assuming the GW counterpart GRB with three typical GRB Band spectral 
models, two typical duration timescales (1 s, 10 s) from the center 
of the LIGO-Virgo location probability map (RA=181 deg, DEC=57 deg), 
the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are 
reported below:

Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV):
1 s:   3.0e-08 erg cm^-2
10 s:  9.1e-08 erg cm^-2

Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV):
1 s:   5.0e-08 erg cm^-2
10 s:  1.5e-07 erg cm^-2

Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV):
1 s:   2.3e-07 erg cm^-2
10 s:  6.8e-07 erg cm^-2

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 spacecraft.

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 could be found at: http://www.hxmt.org.