LIGO/Virgo S190521r
GCN Circular 24744
Subject
LIGO/Virgo S190521r: Gaia Photometric Alerts transient candidate
Date
2019-06-04T16:31:05Z (6 years ago)
From
Deepak Eappachen at SRON Netherlands <d.eappachen@sron.nl>
Z. Kostrzewa-Rutkowska, D. Eappachen (SRON/RU), S. Hodgkin, A. Delgado,
D.L. Harrison, M.van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), P.G. Jonker
(SRON/RU) on behalf of Gaia Alerts team report the discovery of a transient
candidate within the probability skymap of S190521r (LIGO/VIRGO
Collaboration GCN 24632):
---------------------------------------------------------------------------
Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL
----------------------------------------------------------------------------
Gaia19cbb AT2019gui 2019-06-01T13:45:58 306.02533 32.05174 18.28
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19cbb/
---------------------------------------------------------------------------
candidate QSO brightens by 0.7 mag, the source falls in the high confidence region (within the 2% contour of the bayestar map)
Acknowledgements: This work has made use of data from the European Space
Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by
the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC
has been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. ZKR, DE, and PGJ
acknowledge support from the European Research Council under ERC
Consolidator Grant agreement no 647208.
GCN Circular 24672
Subject
LIGO/Virgo S190521r : Gaia Photometric Alerts transient candidate
Date
2019-05-28T11:53:25Z (7 years ago)
From
Deepak Eappachen at SRON Netherlands <d.eappachen@sron.nl>
Z. Kostrzewa-Rutkowska, D. Eappachen (SRON/RU), S. Hodgkin, A. Delgado,
D.L. Harrison, M.van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), P.G. Jonker
(SRON/RU) on behalf of Gaia Alerts team report the discovery of transient
candidates within the probability skymap of S190521r (LIGO/VIRGO
Collaboration GCN 24632):
---------------------------------------------------------------------------
Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL
���������������������������������������������������������������������������������������������������������������
Gaia19byc AT2019fzr 2019-05-25T19:57:05 280.25271 16.15807 17.03
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19byc/ <http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19byc/>
���������������������������������������������������������������������������������������������������������������
Blue hostless transient, likely a CV candidate.
Acknowledgements: This work has made use of data from the European Space
Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia <https://www.cosmos.esa.int/gaia>), processed by
the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium <https://www.cosmos.esa.int/web/gaia/dpac/consortium>). Funding for the DPAC
has been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. ZKR, DE, and PGJ
acknowledge support from the European Research Council under ERC
Consolidator Grant agreement no 647208.
GCN Circular 24666
Subject
LIGO/Virgo S190521r: CNEOST follow-up observations
Date
2019-05-27T05:24:28Z (7 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Dong Xu, Zi-pei Zhu, Bang-Yao Yu, Chen-zhou Cui, Hui-juan Wang (NAOC),
Bin Li, Hai-bin Zhao (PMO), Tian-meng Zhang, Xu Zhou (NAOC), Xue-feng
Wu, Zhi-ping Jin, Tian-rui Sun, Hao Lu, Ge-tu Zhaori, Ren-quan Hong,
Long-fei Hu (PMO), Xiao-feng Wang, Wen-xiong Li (THU), Li-fan Wang
(PMO/TAMU), Jin-zhong Liu (XAO), Ji-rong Mao, Jin-ming Bai (YNAO),
report on behalf of the CNEOST collaboration
We performed the search for the optical counterpart of LIGO/Virgo
S190521r (LVC, GCN 24632) with the Chinese Near Earth Object Survey
Telescope (CNEOST) at Xuyi, Jiangsu, China. The 3 x 3 deg^2 imager
scanned high probability regions of the LVC localization that are
accessible to CNEOST. Following are statistics of the tiled observations:
StartTime (UT): 2019-05-21T15:41:24.772
EndTime (UT): 2019-05-21T18:58:17.206
Skycover (Square Degree): 558.0
#id CentRA(D) CentDEC(D) LimiteMag3_sig 5_sig 10_sig Filter
1 256.829041 -6.872913 18.906 17.909 17.240 VR
2 263.413177 -1.295197 18.800 17.806 17.101 VR
3 266.871521 4.283368 18.938 17.940 17.189 VR
4 260.596588 1.530886 18.954 17.973 17.259 VR
5 254.027359 -6.888728 18.816 17.862 17.191 VR
6 255.475098 -12.495871 18.512 17.530 16.844 VR
7 258.430573 -4.105478 18.924 17.890 17.219 VR
8 263.388000 1.514573 18.899 17.867 17.125 VR
9 264.045441 4.303978 18.962 17.958 17.209 VR
10 257.776398 -1.294184 18.856 17.902 17.240 VR
11 253.024246 -9.658165 18.851 17.853 17.180 VR
12 255.829697 -9.686105 18.821 17.822 17.170 VR
13 260.619476 -1.281923 18.921 17.919 17.255 VR
14 266.239868 1.524753 18.916 17.893 17.176 VR
15 261.243134 4.316584 18.997 17.975 17.204 VR
16 255.604233 -4.063662 18.796 17.848 17.179 VR
17 252.588333 -12.481894 18.730 17.778 17.132 VR
18 270.061768 9.874986 19.504 18.502 17.592 VR
19 278.463013 12.668616 19.556 18.571 17.582 VR
20 277.198456 18.282120 19.539 18.579 17.618 VR
21 269.861023 12.686904 19.543 18.561 17.643 VR
22 268.135651 7.094193 19.438 18.450 17.563 VR
23 272.937866 9.901986 19.409 18.434 17.513 VR
24 278.957642 15.476604 19.641 18.638 17.682 VR
25 277.198456 18.282120 19.539 18.579 17.618 VR
26 269.861023 12.686904 19.543 18.561 17.643 VR
27 268.135651 7.094193 19.438 18.450 17.563 VR
28 272.937866 9.901986 19.409 18.434 17.513 VR
29 278.957642 15.476604 19.641 18.638 17.682 VR
30 276.081696 15.470144 19.592 18.620 17.690 VR
31 267.238159 9.903188 19.570 18.565 17.649 VR
32 283.112885 18.275036 19.572 18.647 17.462 VR
33 293.939850 23.857258 19.854 18.915 17.552 VR
34 295.872009 29.443975 19.790 18.872 16.935 VR
35 284.753967 23.871096 19.637 18.700 17.547 VR
36 285.074524 21.086744 19.661 18.703 17.557 VR
37 293.939850 23.857258 19.854 18.915 17.552 VR
38 295.872009 29.443975 19.790 18.872 16.935 VR
39 288.274506 26.684416 19.757 18.806 17.457 VR
40 282.108063 21.065495 19.696 18.709 17.592 VR
41 287.858276 23.898252 19.692 18.740 17.593 VR
42 294.522736 26.683321 19.925 19.008 17.375 VR
43 292.672424 29.453629 19.845 18.924 17.228 VR
44 284.753967 23.871096 19.637 18.700 17.547 VR
45 301.318268 32.231853 19.783 18.872 17.461 VR
46 311.219604 35.047432 19.731 18.844 17.486 VR
47 321.477234 35.044441 19.787 18.838 17.540 VR
48 321.120056 32.208073 19.759 18.821 17.537 VR
49 311.248566 32.256496 19.797 18.881 17.570 VR
50 299.083832 29.438494 19.977 19.067 17.377 VR
51 304.624878 32.250858 19.814 18.893 17.764 VR
52 314.688507 35.058681 19.851 18.874 17.503 VR
53 324.914825 35.024250 19.810 18.847 17.540 VR
54 317.852173 32.231461 19.811 18.805 17.484 VR
55 307.892761 32.248425 19.958 18.992 17.790 VR
56 299.083832 29.438494 19.977 19.067 17.377 VR
57 304.624878 32.250858 19.814 18.893 17.764 VR
58 314.688507 35.058681 19.851 18.874 17.503 VR
59 324.914825 35.024250 19.810 18.847 17.540 VR
60 317.852173 32.231461 19.811 18.805 17.484 VR
61 307.892761 32.248425 19.958 18.992 17.790 VR
62 299.083832 29.438494 19.977 19.067 17.377 VR
Apart from our previously reported optical transient (OT), OPEM-19ki in
GCN 24647, which was also observed by RATIR (GCN 24650) and ATLAS (GCN
24653), we discovered another OT as well. Both of them are finally found
unrelated with LIGO/Virgo S190521r.
GCN Circular 24661
Subject
LIGO/Virgo S190521r: Kanata optical/NIR follow-up observations of the CNEOST Transient
Date
2019-05-24T23:02:01Z (7 years ago)
From
Mahito Sasada at Hiroshima University <sasadam@hiroshima-u.ac.jp>
Sasada, M., Nakaoka, T., Akitaya, H., Imazato, F. (Hiroshima U.) on behalf
of J-GEM collaboration
We observed the optical transient identified by CNEOST (Li et al., GCN
Circ. 24647) at two epochs using the 1.5-m Kanata telescope at
Higashi-Hiroshima Observatory with HONIR (Akitaya et al. 2014, Proc SPIE,
9147, 91474O) and HOWPol (Kawabata, K. S., et al. 2008, Proc. SPIE, 7014,
151).
We confirmed that the transient existed at the position where Li et al.
reported. We derived following magnitudes for the transient based on the
magnitudes of the field stars taken in the same frames (in AB system;
PanSTARRS and 2MASS catalogs):
MJD 58625.66
B = 18.19 +/- 0.06
V = 17.83 +/- 0.04
R = 17.87 +/- 0.02
J = 18.41 +/- 0.04
MJD 58627.59
B = 18.45 +/- 0.05
V = 18.11 +/- 0.03
R = 18.04 +/- 0.02
J = 18.72 +/- 0.10
The Galactic extinction has not corrected for. These suggest that the
transient faded by about 0.3 mag in 2 days.
=================================
Name: Mahito Sasada
Affiliation: Hiroshima University
E-mail address: sasadam@hiroshima-u.ac.jp <sasada.mahito@naoj.ac.jp>
=================================
GCN Circular 24660
Subject
LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
Date
2019-05-24T11:46:57Z (7 years ago)
From
Damien Turpin at NAOC (CAS) <dturpin-astro@hotmail.com>
LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
D. Turpin (NAOC), N. Dagoneau (CEA/AIM), L.P. Xin (NAOC),
X.H. Han (NAOC), J.Y. Wei (NAOC), C. Wu (NAOC), L. Huang (NAOC),
Y. Xu (NAOC), H.B. Cai (NAOC), J. Wang (NAOC), X.M. Lu (NAOC),
Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Jia (NAOC), S.C. Zou (NAOC),
S.F. Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC), D.W. Xu (NAOC),
Y.J. Xiao (NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC), P.P. Zhang (NAOC),
R.S. Zhang (NAOC), E.W. Liang (GXU), X.G. Wang (GXU), Z.G. Dai (NJU),
X.Y. Wang (NJU), Y.G. Yang (HBNU), J.R. Mao (YNAO), B. Cordier (CEA/AIM),
S. Basa (CNRS/LAM), J.L. Atteia (UPS/IRAP), D. G�tz (CEA/AIM),
A. Claret (CEA/AIM), N. Leroy (CNRS/LAL), C. Lachaud (CNRS/APC),
E. Le Floc'h (CEA/AIM), S.N. Zhang (IHEP), B.B. Wu (IHEP),
report on behalf of the SVOM Ground Follow-up Group:
We observed 12 sky regions to cover the initial skymap of the
LIGO/Virgo trigger S190521r (GCN24632), with the SVOM/GWAC-F30
telescope operated by Huaibei Normal University and NAOC, CAS
at Xinglong Observatory, China.
The SVOM/GWAC-F30 is equipped with Standard Johnson filters
and 3Kx3K FLI CCD (FOV~1.8x1.8 degree). The GWAC-F30 is using
tiling observation strategy. The tiles are calculated to cover
the most probable regions of the 90% localization area given in the
GW probability skymap. Several images with a single exposure of 60s
time in R band are taken for each tile.
The 12 tile coordinates and the observation periods are listed below:
# Ra[hms] Dec[dms] start-obs[UTC] Total_exp[s] N_image R_lim
1 18:21:52.801 +14:27:00.00 2019-05-21T14:25:25.305 300.0 5 14.26
2 18:32:50.399 +17:51:00.00 2019-05-21T14:32:37.560 300.0 5 14.11
3 18:30:21.600 +16:08:60.00 2019-05-21T14:35:33.417 300.0 5 16.38
4 19:08:35.999 +22:57:00.00 2019-05-21T14:45:16.739 300.0 5 13.38
5 19:15:40.799 +24:39:00.00 2019-05-21T14:55:28.205 300.0 5 14.23
6 18:02:52.800 +09:21:00.00 2019-05-21T15:04:44.953 300.0 5 14.72
7 18:37:23.999 +16:08:60.00 2019-05-21T15:13:00.797 300.0 5 15.53
8 18:08:12.001 +11:03:00.00 2019-05-21T15:21:21.874 300.0 5 14.03
9 18:07:33.600 +12:45:00.00 2019-05-21T15:29:22.493 300.0 5 14.85
10 18:23:19.201 +16:08:60.00 2019-05-21T15:37:16.618 240.0 4 13.47
11 18:01:16.799 +11:03:00.00 2019-05-21T15:45:37.945 300.0 5 14.83
12 19:01:14.401 +22:57:00.00 2019-05-21T15:52:45.649 300.0 5 15.20
The covering map is available at:
http://cmm.svom.cn/gwpub/O3/S190521r/S190521r_GWAC-F30.png
(user:svomo3 pwd:gwo3)
The first image was taken ~7.3 hours after the event trigger time. The
weather conditions were partly cloudy during the night.
No credible new source is detected by our online pipeline.
A more detailed image analysis is in progress with our offline pipeline
to search for any fainter transient candidate.
GCN Circular 24659
Subject
LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
Date
2019-05-24T11:45:42Z (7 years ago)
From
Damien Turpin at NAOC (CAS) <dturpin-astro@hotmail.com>
D. Turpin (NAOC), N. Dagoneau (CEA/AIM), L.P. Xin (NAOC),
X.H. Han (NAOC), J.Y. Wei (NAOC), C. Wu (NAOC), L. Huang (NAOC),
Y. Xu (NAOC), H.B. Cai (NAOC), J. Wang (NAOC), X.M. Lu (NAOC),
Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Jia (NAOC), S.C. Zou (NAOC),
S.F. Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC), D.W. Xu (NAOC),
Y.J. Xiao (NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC), P.P. Zhang (NAOC),
R.S. Zhang (NAOC), E.W. Liang (GXU), X.G. Wang (GXU), Z.G. Dai (NJU),
X.Y. Wang (NJU), Y.G. Yang (HBNU), J.R. Mao (YNAO), B. Cordier (CEA/AIM),
S. Basa (CNRS/LAM), J.L. Atteia (UPS/IRAP), D. G�tz (CEA/AIM),
A. Claret (CEA/AIM), N. Leroy (CNRS/LAL), C. Lachaud (CNRS/APC),
E. Le Floc'h (CEA/AIM), S.N. Zhang (IHEP), B.B. Wu (IHEP),
report on behalf of the SVOM Ground Follow-up Group:
We observed 9 sky regions (total: 147.3 square degrees) to cover the
initial skymap of the LIGO/Virgo trigger S190521r (GCN24632), with
SVOM/GWAC, at Xinglong Observatory, equipped with a set of two types
of wide angle cameras: FFOV cameras (FOV~900 square degrees/camera,
aperture = 3.5cm) and JFOV cameras (FOV~150 square degrees/camera,
aperture = 18cm).
SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras,
working with unfiltered band. The observations are operated in time-series
mode, taking one exposure every 15 seconds (10s exposure + 5s readout).
We estimate a 30.2% prior probability that these 9 regions contain the
true location of the source.
The coordinates of the 9 regions and observation time are listed below:
# Ra[deg] Dec[deg] start-obs(UTC) end-obs(UTC) FoV
1 277.934 18.1817 2019-05-22 15:48:27 2019-05-22 17:58:07 12.5x12.5 deg
2 264.736 18.0991 2019-05-22 15:56:09 2019-05-22 17:58:07 12.5x12.5 deg
3 278.536 30.4064 2019-05-22 16:10:35 2019-05-22 17:58:08 12.5x12.5 deg
4 264.327 30.1808 2019-05-22 17:50:50 2019-05-22 17:58:07 12.5x12.5 deg
5 334.381 18.0954 2019-05-22 18:20:31 2019-05-22 19:02:15 12.5x12.5 deg
6 321.183 18.0074 2019-05-22 18:22:32 2019-05-22 19:02:15 12.5x12.5 deg
5 332.268 18.1257 2019-05-22 18:24:45 2019-05-22 19:04:27 12.5x12.5 deg
6 321.343 18.5382 2019-05-22 18:25:58 2019-05-22 18:34:28 12.5x12.5 deg
7 320.76 30.1094 2019-05-22 18:29:25 2019-05-22 18:59:00 12.5x12.5 deg
7 320.628 29.7237 2019-05-22 18:31:38 2019-05-22 18:56:45 12.5x12.5 deg
8 334.97 30.349 2019-05-22 18:35:30 2019-05-22 19:02:15 12.5x12.5 deg
9 342.46 35.0794 2019-05-22 19:15:29 2019-05-22 19:19:32 12.5x12.5 deg
The covering map is available at:
http://cmm.svom.cn/gwpub/O3/S190521r/S190521r_GWAC.png
(user:svomo3 pwd:gwo3)
The first image was taken ~1.3 days after the event trigger time. The
weather conditions were partly cloudy during the two consecutive days
of observations. A 3 sigma limiting magnitude of about 16 mag in R band
is typically obtained in our single frames.
No credible new source is detected by our online pipeline.
A more detailed image analysis including co-addition is ongoing with
our offline pipeline to search for faint transient candidates.
GCN Circular 24653
Subject
LIGO/Virgo S190521r: No candidate counterparts from ATLAS observations of the skymap
Date
2019-05-22T13:56:40Z (7 years ago)
From
Shubham Srivastav at QUB <S.Srivastav@qub.ac.uk>
---- End of SpamAssassin results
X-MS-Exchange-Organization-SCL: 0
Content-Transfer-Encoding: 8bit
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S. Srivastav, P. Clark, K. W. Smith, D. R. Young, S. J. Smartt (QUB)
L. Denneau, H. Flewelling, A. Heinze, J. Tonry, H. Weiland (IfA, Univ. Hawaii),
O. McBrien, J. Gillanders, D. O���Neil, S. Sim (QUB) A. Rest (STScI), B. Stalder (LSST), C. Stubbs (Harvard)
We report observations of the BAYESTAR skymap of the BBH event S190521r (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 24632) with the ATLAS telescope system (Tonry et al. 2018, PASP, 13, 164505). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa employing two filters cyan and orange. While carrying out the primary mission for Near Earth Objects, we can adjust the schedule rapidly to point at LVC gravitational wave skymaps.
Sequences of 30 sec images were taken in the ATLAS o band, and at each pointing position a sequence of quads (4 x 30 sec) was taken. The images were processed with the ATLAS pipeline and reference images subtracted from each one. Transient candidates were run through our standard filtering procedures, combined with machine learning algorithms (e.g. Wright et al. 2015, MNRAS, 449, 451). Candidates were spatially cross-matched with known minor planets, and star, galaxy, AGN and multi-wavelength catalogues (as described in Smartt et al. 2016, MNRAS, 462 4094, Stalder et al. 2017, ApJ, 850, 149).
We covered 488 square degrees of the bayestar map 90% credible region and covered a sky region totalling 96% of the event���s full localisation likelihood. Data acquisition began at MJD 58624.333909 or 2019-05-21 08:00:49.7 (UTC), ~11 mins after the PRELIMINARY notice and ~17 mins after the GW merger event. All data acquisition finished approximately 5 hours later.
We found no new transients to magnitudes of o < 18.7 (the median of the 5 sigma limits of the individual 30 sec images) between ~20 to ~320 minutes after the BBH merger.
We also report previous detection of the CNEOST transient (Li et al., GCN 24647) by ATLAS, designated as ATLAS19kvc. ATLAS19kvc (or AT 2019fsk) was first detected on 2019-05-15.43 UT (MJD 58618.43) at a magnitude of
m_o = 17.33 +/- 0.06, with subsequent detections on 2019-05-17 and 2019-05-21. ATLAS19kvc is therefore
unrelated to the gravitational wave event S190521r.
This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, and the Space Telescope Science Institute.
GCN Circular 24650
Subject
LIGO/Virgo S190521r: RATIR Optical and NIR Observations of the CNEOST Transient
Date
2019-05-22T06:20:23Z (7 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Diego
Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM),
Margarita Pereyra (UNAM), Eleonora Troja (GSFC/UMD), and Tanner Wolfram
(ASU) report:
We observed the field of the optical transient observed by CNEOST (Li et
al., GCN Circ. 24647) with the Reionization and Transients Infrared
Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at
the Observatorio Astron��mico Nacional on Sierra San Pedro M��rtir from
2019/05 22.22 to 2019/05 22.23 UTC, obtaining a total of 0.18 hours
exposure in the r and i bands and 0.07 hours exposure in the Z, Y, J,
and H bands.
The source is located at RA, Dec = 17:19:41.79, +01:04:44.9 (J2000,
+/-0.5"). In comparison with the SDSS DR9 and 2MASS catalogs, we obtain
the following detections:
r = 17.88 +/- 0.01
i = 17.93 +/- 0.02
Z = 18.08 +/- 0.06
Y = 18.15 +/- 0.08
J = 18.27 +/- 0.14
H = 18.61 +/- 0.24
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
We note that the spectrum is not especially red and can be well-fitted by a
power law with F_\nu \proportional to \nu. The source does not appear to
have faded dramatically since the CNEOST observations about 13 hours
previously.
Further observations are planned.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 24649
Subject
LIGO/Virgo S190521r: No transient candidates from CALET observations
Date
2019-05-22T03:04:49Z (7 years ago)
From
Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>
S. Ozawa (Waseda U), A. Yoshida, T. Sakamoto,
V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), 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:
At the trigger time of the compact binary merger candidate S190521r,
T0 = 2019-05-21 07:43:59.463 UT (The LIGO Scientific Collaboration
and Virgo Collaboration, GCN Circ. 24632), the CALET Gamma-ray
Burst Monitor (CGBM) high voltages were off (from T0-6 min to
T0+11 min).
The CALET Calorimeter (CAL) was operating in high energy trigger
mode at the trigger time of S190521r. Using the CAL data, we have
searched for gamma-ray events in the 10-100 GeV band from -60
sec to +60 sec from the GW trigger time and found no candidates.
There is no significant overlap with the LVC location probability map.
The CAL FOV was centered at RA = 225.3 deg, Dec = 51.4 deg at T0.
GCN Circular 24647
Subject
LIGO/Virgo S190521r: One optical transient from CNEOST
Date
2019-05-22T02:11:08Z (7 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Bin Li, Hai-bin Zhao (PMO), Dong Xu, Zi-pei Zhu, Bang-Yao Yu,Tian-meng
Zhang, Xu Zhou, Chen-zhou Cui, Hui-juan Wang (NAOC), Xue-feng Wu,
Zhi-ping Jin, Tian-rui Sun, Hao Lu, Ge-tu Zhaori, Ren-quan Hong,
Long-fei Hu (PMO), Xiao-feng Wang, Wen-xiong Li (THU), Li-fan Wang
(PMO/TAMU), Jin-zhong Liu (XAO), Ji-rong Mao, Jin-ming Bai (YNAO),
report on behalf of the CNEOST collaboration
We performed the search for the optical counterpart of LIGO/Virgo
S190521r (LVC, GCN 24632) with the Chinese Near Earth Object Survey
Telescope (CNEOST) at Xuyi, Jiangsu, China. The 3 x 3 deg^2 imager
scanned high probability regions of the LVC localization that are
accessible to CNEOST. Statistical results on the search will be reported
later, and here we report an optical transient.
The OT is localised at coordinates:
R.A. (J2000) = 17:19:41.85
Dec. (J2000) = +01:04:45.19
with an uncertainty of ~ 0.5 arcsec. The OT had m(VR) ~ 17.8 mag at
15:48:04 UT on 2019-05-21, and appeared at the above position in three
images with time interval of ~ 40 mins. At the above position, there
exists a very low S/N object in the PanSTARRS and SDSS surveys. The
object had m(r) ~ 23.3 mag, and seems extended to some extent.
Verification of the OT is encouraged.
GCN Circular 24645
Subject
LIGO/Virgo S190521r: Swift/BAT Counterpart Search
Date
2019-05-21T21:16:20Z (7 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (NASA/GSFC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
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(ASDC), 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. 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 S190521r (LIGO/VIRGO Collaboration GCN Circ. 24632),
where T0 is the LVC trigger time (2019-05-21T07:43:59.463 UTC).
The center of the BAT FOV at T0 is
RA = 113.108 deg,
DEC = -13.516 deg,
and the ROLL angle is 295.891 deg.
The BAT Field of View (>10% partial coding) covers 0.00% of the integrated
LVC localization probability.
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 ~ 7.50 x 10^-8 erg/s/cm^2.
Event data are available from T-101.444 s to T-98.314 s. No significant
detections are found in the 15-350 keV image made using the whole event
data duration.
BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 33.41% 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/S190521r/web/source.html
GCN Circular 24643
Subject
LIGO/Virgo S190521r: Coverage and upper limits from Fermi-LAT observations
Date
2019-05-21T18:17:12Z (7 years ago)
From
Elisabetta Bissaldi at INFN,Bari <elisabetta.bissaldi@ba.infn.it>
E. Bissaldi (Politecnico & INFN Bari), M. Axelsson (KTH & Stockholm Univ.),
and D. Tak (Univ. of Maryland),
report on behalf of the Fermi-LAT Collaboration:
We have searched data collected by the Fermi Large Area Telescope (LAT)
on May 21, 2019, for possible high-energy (E > 100 MeV)
gamma-ray emission in spatial/temporal coincidence with
the LIGO/Virgo trigger S190521r (GCN 24632).
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 ~50% of the LIGO probability
at the time of the trigger (T0 = 2019-05-21 07:43:59.463 UTC),
and reached 100% cumulative coverage after ~4.3 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
3.0e-10 and 6.4e-09 [erg/cm^2/s].
The Fermi-LAT point of contact for this event is Donggeun Tak
(takdg123@umd.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 24642
Subject
LIGO/Virgo S190521r: Upper limits from Fermi-GBM observations
Date
2019-05-21T17:45:13Z (7 years ago)
From
Suraj Poolakkil at UAH <sp0076@uah.edu>
S. Poolakkil (UAH) and A. Goldstein (USRA) report on behalf of the
Fermi-GBM Team and the GBM-LIGO/Virgo group:
For S190521r, and using the initial BAYESTAR skymap, Fermi-GBM was
observing 100.0% of the localization probability at event time.
There was no Fermi-GBM onboard trigger around the event time of the
LIGO/Virgo detection of GW trigger S190521r (GCN 24632). 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.
We therefore set upper limits on impulsive gamma-ray emission. Using the
representative soft, normal, and hard GRB-like spectral templates described
in arXiv:1612.02395, we set the following 3 sigma flux upper limits over
10-1000 keV, weighted by the remaining visible GW localization probability
(in units of erg/s/cm^2):
Timescale soft norm hard
--------------------------------------
0.128 s: 6.5e-07 8.4e-07 2.1e-06
1.024 s: 1.6e-07 2.4e-07 4.3e-07
8.192 s: 5.8e-08 7.8e-08 1.5e-07
Assuming the median luminosity distance of ~1136 Mpc from the GW detection,
we estimate intrinsic luminosity upper limits of (1.4-16.1)E49 erg/s for the
soft template, (1.7-18.8)E49 erg/s for the normal template, and
(5.5-78.2)E49 erg/s for the hard template over the 1 keV-10 MeV energy
range.
GCN Circular 24638
Subject
LIGO/Virgo S190521r: Upper limits from AGILE-GRID observations
Date
2019-05-21T11:52:18Z (7 years ago)
From
Francesco Verrecchia at ASDC <francesco.verrecchia@ssdc.asi.it>
F. Verrecchia (SSDC, and INAF-OAR), C. Casentini (INAF/IAPS), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata),�� F. Lucarelli, C. Pittori
(SSDC, and
INAF-OAR), M. Cardillo, G. Piano A. Ursi (INAF/IAPS), 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 S190521r at T0 = 2019-05-21
07:43:59.463
UTC (GCN #24632) a preliminary analysis of the AGILE exposure at T0 showed
the S190521g 90% c.l. localization region (LR) was not exposed by the
Gamma-Ray
Imaging Detector (GRID). The closest exposure in time occurred at T0-15s
covering about 40% of the LR at off-axis angles between 50 and 60 deg.
We performed an analysis of the GRID data in the energy range 50 MeV -
10 GeV
over three time intervals before and after T0, when good exposure of
the S190521r 90% c.l. LR was available.
The following preliminary GRID 3-sigma upper limit (UL) values are obtained
over a large area of the exposed LR:
(T0-15s; T0-5s ): from 1.3e-06 to 3.0e-06 erg cm^-2 s^-1, with exposure of
about 40% of the LR;
(T0-100s; T0 ): from 3.5e-08 to 4.5e-07 erg cm^-2 s^-1, with exposure of
about 60% of the LR;
(T0+200s; T0+300s): from 5.2e-08 to 6.4e-07 erg cm^-2 s^-1, with exposure of
about 80% of the LR.
An image of the AGILE-GRID 10s exposure near T0 is available at the site
https://tools.ssdc.asi.it/ImgView/Agile/S190521r_T0-15s_d10s_FM_UL-E50offbm14
These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.
GCN Circular 24637
Subject
LIGO/Virgo S190521r Global MASTER-Net observations report
Date
2019-05-21T11:01:53Z (7 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, V.V.Chazov, D. Vlasenko
(Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University)
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
(Irkutsk State University)
V. Yurkov, A. Gabovich, Yu. Sergienko
(Blagoveschensk Educational State University, Blagoveschensk)
R. Podesta, Carlos Lopez and F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA))
Hugo Levato and Carlos Saffe
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE))
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
(The Instituto de Astrofisica de Canarias)
D. Buckley, S. Potter, A. Kniazev, M. Kotze
(South African Astronomical Observatory)
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the LIGO/Virgo S190521r errorbox 427 sec after trigger time at 2019-05-21 07:51:06 UT, with upper limit up to 17.6 mag. The observations began at zenit distance = 75 deg. The sun altitude is -44.1 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=10407
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
473 | 2019-05-21 07:51:06 | MASTER-OAFA | ( 20h 34m 44.39s , +32d 44m 02.74s) | C | 90 | 17.0 |
598 | 2019-05-21 07:51:06 | MASTER-OAFA | ( 20h 34m 44.40s , +32d 44m 02.69s) | C | 340 | 17.6 | Coadd
613 | 2019-05-21 07:53:17 | MASTER-OAFA | ( 20h 34m 44.20s , +32d 44m 08.83s) | C | 110 | 17.1 |
781 | 2019-05-21 07:55:49 | MASTER-OAFA | ( 20h 34m 44.01s , +32d 44m 13.71s) | C | 140 | 17.1 |
982 | 2019-05-21 07:58:51 | MASTER-OAFA | ( 20h 34m 43.80s , +32d 44m 16.83s) | C | 180 | 17.2 |
1904 | 2019-05-21 08:14:12 | MASTER-OAFA | ( 21h 7m 57.50s , +33d 55m 58.59s) | C | 180 | 16.6 |
2603 | 2019-05-21 08:25:52 | MASTER-OAFA | ( 21h 7m 57.26s , +33d 55m 38.68s) | C | 180 | 16.6 |
2835 | 2019-05-21 08:29:43 | MASTER-OAFA | ( 21h 17m 35.60s , +33d 55m 57.36s) | C | 180 | 16.9 |
3015 | 2019-05-21 08:29:43 | MASTER-OAFA | ( 21h 17m 35.60s , +33d 55m 57.34s) | C | 540 | 17.4 | Coadd
3059 | 2019-05-21 08:33:27 | MASTER-OAFA | ( 21h 17m 33.96s , +33d 56m 01.41s) | C | 180 | 16.9 |
3330 | 2019-05-21 08:37:59 | MASTER-OAFA | ( 20h 39m 28.03s , +31d 56m 43.84s) | C | 180 | 17.1 |
3557 | 2019-05-21 08:41:45 | MASTER-OAFA | ( 21h 17m 33.53s , +33d 55m 47.16s) | C | 180 | 17.0 |
3784 | 2019-05-21 08:45:33 | MASTER-OAFA | ( 21h 46m 31.06s , +33d 55m 41.51s) | C | 180 | 17.1 |
4094 | 2019-05-21 08:50:43 | MASTER-OAFA | ( 20h 39m 29.03s , +31d 56m 24.26s) | C | 180 | 17.2 |
4457 | 2019-05-21 08:56:46 | MASTER-OAFA | ( 20h 34m 42.15s , +32d 44m 17.24s) | C | 180 | 17.1 |
4637 | 2019-05-21 08:56:46 | MASTER-OAFA | ( 20h 34m 42.15s , +32d 44m 17.14s) | C | 540 | 17.5 | Coadd
4679 | 2019-05-21 09:00:27 | MASTER-OAFA | ( 20h 34m 41.96s , +32d 44m 16.49s) | C | 180 | 17.2 |
4900 | 2019-05-21 09:04:09 | MASTER-OAFA | ( 20h 34m 41.81s , +32d 44m 14.63s) | C | 180 | 17.2 |
5121 | 2019-05-21 09:07:50 | MASTER-OAFA | ( 20h 34m 41.74s , +32d 44m 14.01s) | C | 180 | 17.2 |
5348 | 2019-05-21 09:11:36 | MASTER-OAFA | ( 21h 46m 28.55s , +33d 55m 37.61s) | C | 180 | 17.1 |
5577 | 2019-05-21 09:15:25 | MASTER-OAFA | ( 21h 56m 07.73s , +33d 55m 09.20s) | C | 180 | 17.1 |
6036 | 2019-05-21 09:23:05 | MASTER-OAFA | ( 20h 48m 54.49s , +31d 56m 28.30s) | C | 180 | 16.9 |
6268 | 2019-05-21 09:26:56 | MASTER-OAFA | ( 21h 56m 07.41s , +33d 55m 27.03s) | C | 180 | 17.2 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 24636
Subject
LIGO/Virgo S190521r: No counterpart candidate in AGILE-MCAL observations
Date
2019-05-21T09:45:11Z (7 years ago)
From
Claudio Casentini at INAF-IAPS <claudio.casentini@inaf.it>
C.Casentini (INAF/IAPS), F.Verrecchia (SSDC, and INAF/OAR), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), M.Cardillo, G.Piano, A.Ursi
(INAF/IAPS), F.Lucarelli, C. Pittori (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 S190521r at T0 = 2019-05-21T07:43:59
(UT), a preliminary analysis of the AGILE minicalorimeter (MCAL) triggered
data found no event candidate within a time interval covering +/- 15 sec
from the LIGO/Virgo T0.
Three-sigma upper limits (ULs) are obtained for a 1 s integration time at
different celestial positions within the accessible 90% c.l. localization
region (LR) of S190521r (almost 80% of the LR), from a minimum of 1.6E-06
erg cm^-2 to a maximum of 7.6E-06 erg cm^-2 (assuming as spectral model a
single power law with photon index 1.5). The average off-axis angle is
about 70 degrees.
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.
GCN Circular 24635
Subject
LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
Date
2019-05-21T09:35:58Z (7 years ago)
From
Motoko Serino at RIKEN/MAXI <motoko@crab.riken.jp>
M. Serino, S. Sugita (AGU),
N. Kawai, M. Sugizaki (Tokyo Tech), H. Negoro (Nihon U.),
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 S190521r at 2019-05-21 07:43:59.463 UTC (GCN 24632).
At the trigger time of S190521r, the high-voltage of MAXI/GSC was off,
and it was turned on at T0+848 sec (+14.1 min).
The first one-orbit (92 min) scan observation with GSC after the event covered 99%
of the 90% credible region of the bayestar skymap from 07:58:17 to 09:09:32 UTC (T0+858 to T0+5133 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.
GCN Circular 24634
Subject
LIGO/Virgo S190521r: No neutrino counterpart candidates in ANTARES search
Date
2019-05-21T09:28:58Z (7 years ago)
From
Damien Dornic at CPPM,France <dornic@cppm.in2p3.fr>
M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite Paris Diderot), M. Colomer (APC/Universite Paris Diderot)), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), 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 S190521r event using the 90% contour of the bayestar probability map provided by the GW interferometers (GCN#24632). The ANTARES visibility at the time of the alert, together with the 50% and 90% contours of the probability map are shown at https://www.cppm.in2p3.fr/~dornic/events_runo3/S190521r.png. Considering the location probability provided by the LIGO/Virgo collaborations, there is a 30% 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 (2019-05-21 07:43:59 UT) and in the 90% contour of the S190521r event. The expected number of atmospheric background events in the region visible by ANTARES is 7.4e-5 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 5.3e-4 in this larger time window.
ANTARES 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.
GCN Circular 24633
Subject
LIGO/Virgo S190521r: IceCube Neutrino Search
Date
2019-05-21T08:42:39Z (7 years ago)
From
Raamis Hussain at IceCube <raamis.hussain@icecube.wisc.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
IceCube has performed a search for track-like muon neutrino events
consistent with the sky localization of S190521r-1-Preliminary in a time
range of 1000
seconds centered on the alert event time (2019-05-21 07:35:39.463 UTC to
2019-05-21 07:52:19.463 UTC)
during which IceCube was collecting good quality data.
No track-like events are found in spatial coincidence with the 90% spatial
containment of S190521r-1-Preliminary calculated from the map
circulated in the preliminary notice.
IceCube's sensitivity to point sources within the location spanned by the
90% spatial containment of S190521r-1-Preliminary ranges from
0.029 to 0.456 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
GCN Circular 24632
Subject
LIGO/Virgo S190521r: Identification of a GW compact binary merger candidate
Date
2019-05-21T08:41:27Z (7 years ago)
From
Shasvath J. Kapadia at U. of Wisconsin, Milwaukee <kapadia@uwm.edu>
The LIGO Scientific Collaboration and the Virgo Collaboration report:
We identified the compact binary merger candidate S190521r during
real-time processing of data from LIGO Hanford Observatory (H1) and
LIGO Livingston Observatory (L1) at 2019-05-21 07:43:59.463 UTC (GPS
time: 1242459857.463). The candidate was found by the PyCBC Live [1],
SPIIR [2], CWB [3], and GstLAL [4] analysis pipelines.
S190521r is an event of interest because its false alarm rate, as
determined by the online analysis, is 3.2e-10 Hz, or about one in 100
years. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S190521r
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 skymap is available at this time and can be retrieved from the
GraceDB event page:
* bayestar.fits.gz, an updated localization generated by BAYESTAR
[5], distributed via GCN notice about 6 minutes after the candidate
For the bayestar.fits.gz skymap, the 90% credible region is 488 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 1136 +/- 279 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] Qi Chu, PhD Thesis, The University of Western Australia (2017)
[3] Klimenko et al. PRD 93, 042004 (2016)
[4] Messick et al. PRD 95, 042001 (2017)
[5] Singer & Price PRD 93, 024013 (2016)
GCN Circular 24630
Subject
LIGO/Virgo S190521r: No counterpart candidates in HAWC observations
Date
2019-05-21T08:20:47Z (7 years ago)
From
Hugo Ayala at Pennsylvania State University <hgayala@psu.edu>
The HAWC Collaboration (https://www.hawc-observatory.org) reports:
The HAWC Collaboration performed a follow-up of the gravitational wave
trigger S190521r. At the time of the trigger the HAWC
local zenith was oriented towards (RA, Dec) = (257.1 deg, 19.0 deg).
72% 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 12.6 deg to 45.0 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 1.5e-06 erg/cm^2 to 1.1e-04 erg/cm^2
(8.0e-06 erg/cm^2 to 5.0e-04 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.
GCN Circular 24629
Subject
LIGO/Virgo S190521r: No counterpart candidates in INTEGRAL SPI/ACS prompt observation
Date
2019-05-21T07:59:42Z (7 years ago)
From
Maeve Doyle at U College Dublin, Ireland <maeve.doyle.1@ucdconnect.ie>
Maeve Doyle (UCD, Ireland), Enrico Bozzo,
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
J. Rodi (IAPS-Roma, Italy)
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 <https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration>
Using INTEGRAL/SPI-ACS realtime data (following Savchenko et al. 2017,
A&A 603, A46) we have performed a search for a prompt gamma-ray
counterpart of S190521r.
At the time of the event (2019-05-21 07:43:59 UTC, hereafter T0),
INTEGRAL was operating in nominal mode. The peak of the event
localization probability was at an angle of 125 deg with respect to
the spacecraft pointing axis. This orientation implies strongly
suppressed (3.3% of optimal) response of ISGRI, strongly suppressed
(36% of optimal) response of IBIS/Veto, and somewhat suppressed (53%
of optimal) response o f SPI-ACS.
The background within +/-300 seconds around the event was stable
(excess variance 1.4).
We have performed a search for any impulsive events in INTEGRAL SPI-
ACS (as described in Savchenko et al. 2012, A&A 541A, 122S) data.
We do not detect any significant counterparts and estimate a 3-sigma
upper limit on the 75-2000 keV fluence of 4e-07 erg/cm^2 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 ~3.2e-07 (1.8e-07)
erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.