LIGO/Virgo S230518h
GCN Circular 33814
Subject
LIGO/Virgo S230518h: Upper limits from IceCube neutrino search
Date
2023-05-18T14:37:41Z (2 years ago)
From
Jessie Thwaites at IceCube/U Wisc-Madison <thwaites@wisc.edu>
IceCube Collaboration (http://icecube.wisc.edu/) reports:
A search for track-like muon neutrino events detected by IceCube consistent with the sky localization of gravitational-wave candidate S230518h in a time range of 1000 seconds centered on the alert event time (2023-05-18 12:50:48.000 UTC to 2023-05-18 13:07:28.000 UTC) has been performed [1,2].
During this time period IceCube was collecting good quality data. No significant track-like events are found in spatial coincidence of S230518h 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 S230518h ranges from 0.028 to 1.133 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.
[1] M. G. Aartsen et al 2020 ApJL 898 L10
[2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80
GCN Circular 33815
Subject
LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
Date
2023-05-18T16:57:30Z (2 years ago)
From
Volodymyr Savchenko at ISDC, University of Geneva; LASTRO, EPFL <volodymyr.savchenko@unige.ch>
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
Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed
a search for a prompt gamma-ray counterpart of S230518h (GCN 33813).
At the time of the event (2023-05-18 12:59:08 UTC, hereafter T0),
INTEGRAL was operating in nominal mode. The peak of the event
localization probability was at an angle of 136 deg with respect to
the spacecraft pointing axis. This orientation implies strongly
suppressed (3.7% of optimal) response of ISGRI, somewhat suppressed
(57% of optimal) response of IBIS/Veto, and strongly suppressed (35%
of optimal) response of SPI-ACS.
The background within +/-300 seconds around the event was rather
stable (excess variance 1.3).
We have performed a search for any impulsive events in INTEGRAL SPI-
ACS (as described in [2]) data.
We do not detect any significant counterparts and estimate a 3-sigma
upper limit on the 75-2000 keV fluence of 3.8e-07 erg/cm^2 (within the
50% probability containment 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 ~3.7e-07 (5.8e-08)
erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.
We report for completeness and in order of FAP, all excesses
identified in the search region. We find: 6 likely background
excesses:
T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP
7.98 | 1.15 | 3.1 | 0.494 +/- 0.211 +/- 0.477 | 0.123
-27.1 | 0.2 | 4.3 | 1.6 +/- 0.512 +/- 1.55 | 0.331
213 | 0.8 | 4.3 | 0.815 +/- 0.254 +/- 0.787 | 0.618
10.1 | 0.1 | 3.4 | 1.76 +/- 0.726 +/- 1.7 | 0.923
128 | 2.1 | 3.2 | 0.386 +/- 0.156 +/- 0.373 | 0.945
-28.9 | 0.3 | 3.3 | 1 +/- 0.415 +/- 0.965 | 0.991
Note that FAP estimates (especially at timescales above 2s) may be
possibly further affected by enhanced non-stationary local background
noise. This list excludes any excesses for which FAP is close to
unity.
All results quoted are preliminary.
This circular is an official product of the INTEGRAL Multi-Messenger
team.
Open SPI-ACS data can be retrieved in here
https://www.astro.unige.ch/mmoda/?T1=2023-05-18T12%3A59%3A00.000&T2=2023-05-18T12%3A59%3A18.000&T_format=isot&data_level=ordinary&instrument=spi_acs&product_type=spi_acs_lc&query_status=new&query_type=Real&time_bin=0.05&time_bin_format=sec
Note that we send GCNs Circulars only when one merger contains at least one neutron star or a
significance counterpart is found by any telescope. This policy may be revised, in which case we'll announce it in a GCN.
[1] Savchenko et al. 2017, A&A 603, A46
[2] Savchenko et al. 2012, A&A 541A, 122S
GCN Circular 33817
Subject
LIGO/Virgo S230518h: Global MASTER-Net observations report
Date
2023-05-18T18:28:23Z (2 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko,
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the LIGO/Virgo S230518h errorbox 192 sec after notice time and 10188 sec after trigger time at 2023-05-18 15:48:56 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 83 deg. The sun altitude is -20.3 deg.
MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the LIGO/Virgo S230518h errorbox 3191 sec after notice time and 13187 sec after trigger time at 2023-05-18 16:38:55 UT, with upper limit up to 17.7 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -11.0 deg.
The galactic latitude b = -11 deg., longitude l = 223 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11865
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
10278 | 2023-05-18 15:48:56 | MASTER-Amur | (23h 42m 34.05s , +27d 56m 23.2s) | C | 180 | 16.4 |
10486 | 2023-05-18 15:52:23 | MASTER-Amur | (23h 36m 00.68s , +26d 00m 33.9s) | C | 180 | 16.5 |
10686 | 2023-05-18 15:55:44 | MASTER-Amur | (23h 56m 30.29s , +27d 55m 52.4s) | C | 180 | 15.6 |
11213 | 2023-05-18 16:04:31 | MASTER-Amur | (00h 13m 40.72s , +29d 50m 21.9s) | C | 180 | 15.3 |
11413 | 2023-05-18 16:07:51 | MASTER-Amur | (23h 55m 58.92s , +31d 42m 40.7s) | C | 180 | 17.0 |
11647 | 2023-05-18 16:11:44 | MASTER-Amur | (00h 05m 25.45s , +31d 43m 52.8s) | C | 180 | 16.6 |
12170 | 2023-05-18 16:20:28 | MASTER-Amur | (23h 56m 00.17s , +31d 44m 12.4s) | C | 180 | 16.8 |
12370 | 2023-05-18 16:23:48 | MASTER-Amur | (00h 05m 18.97s , +31d 43m 14.6s) | C | 180 | 16.9 |
12571 | 2023-05-18 16:27:08 | MASTER-Amur | (23h 25m 22.89s , +27d 54m 58.8s) | C | 180 | 17.5 |
12770 | 2023-05-18 16:30:28 | MASTER-Amur | (23h 34m 20.58s , +27d 54m 00.4s) | C | 180 | 17.3 |
12970 | 2023-05-18 16:33:47 | MASTER-Amur | (23h 18m 57.17s , +26d 01m 19.5s) | C | 180 | 17.5 |
13170 | 2023-05-18 16:37:07 | MASTER-Amur | (23h 27m 50.84s , +25d 59m 52.3s) | C | 180 | 17.4 |
13278 | 2023-05-18 16:38:55 | MASTER-SAAO | (06h 32m 29.44s , -23d 26m 27.9s) | C | 180 | 17.3 |
13278 | 2023-05-18 16:38:55 | MASTER-SAAO | (06h 33m 19.54s , -23d 26m 52.9s) | C | 180 | 17.4 |
13370 | 2023-05-18 16:40:27 | MASTER-Amur | (23h 25m 21.09s , +27d 55m 38.3s) | C | 180 | 17.5 |
13489 | 2023-05-18 16:42:27 | MASTER-SAAO | (06h 41m 06.20s , -23d 27m 07.7s) | C | 180 | 15.8 |
13489 | 2023-05-18 16:42:27 | MASTER-SAAO | (06h 41m 56.73s , -23d 27m 32.5s) | C | 180 | 15.7 |
13569 | 2023-05-18 16:43:47 | MASTER-Amur | (23h 34m 18.00s , +27d 54m 49.9s) | C | 180 | 17.5 |
13689 | 2023-05-18 16:45:47 | MASTER-SAAO | (06h 26m 56.44s , -21d 32m 00.9s) | C | 180 | 15.9 |
13689 | 2023-05-18 16:45:47 | MASTER-SAAO | (06h 27m 46.21s , -21d 32m 26.0s) | C | 180 | 15.9 |
13769 | 2023-05-18 16:47:06 | MASTER-Amur | (23h 18m 51.54s , +26d 01m 33.5s) | C | 180 | 17.7 |
13901 | 2023-05-18 16:49:18 | MASTER-SAAO | (06h 35m 40.83s , -21d 32m 55.8s) | C | 180 | 17.7 |
13901 | 2023-05-18 16:49:18 | MASTER-SAAO | (06h 36m 30.85s , -21d 33m 20.5s) | C | 180 | 17.7 |
13968 | 2023-05-18 16:50:26 | MASTER-Amur | (23h 27m 53.06s , +26d 00m 39.5s) | C | 180 | 17.6 |
14112 | 2023-05-18 16:52:49 | MASTER-SAAO | (06h 22m 09.91s , -19d 39m 15.3s) | C | 180 | 15.3 |
14112 | 2023-05-18 16:52:49 | MASTER-SAAO | (06h 22m 59.36s , -19d 39m 40.9s) | C | 180 | 15.4 |
14168 | 2023-05-18 16:53:46 | MASTER-Amur | (23h 26m 09.80s , +20d 17m 47.3s) | C | 180 | 17.5 |
14569 | 2023-05-18 17:00:26 | MASTER-Amur | (23h 27m 45.99s , +22d 13m 09.2s) | C | 180 | 17.4 |
14769 | 2023-05-18 17:03:46 | MASTER-Amur | (23h 36m 17.86s , +22d 12m 37.0s) | C | 180 | 17.4 |
14969 | 2023-05-18 17:07:06 | MASTER-Amur | (23h 26m 03.47s , +20d 19m 20.5s) | C | 180 | 17.4 |
15391 | 2023-05-18 17:14:09 | MASTER-Amur | (23h 27m 38.02s , +22d 11m 11.9s) | C | 180 | 17.5 |
15591 | 2023-05-18 17:17:28 | MASTER-Amur | (23h 36m 21.64s , +22d 11m 45.9s) | C | 180 | 17.4 |
15791 | 2023-05-18 17:20:48 | MASTER-Amur | (23h 30m 53.60s , +24d 05m 24.2s) | C | 180 | 17.6 |
15991 | 2023-05-18 17:24:08 | MASTER-Amur | (23h 39m 42.89s , +24d 07m 13.7s) | C | 180 | 17.6 |
16190 | 2023-05-18 17:27:28 | MASTER-Amur | (00h 13m 23.27s , +27d 55m 46.2s) | C | 180 | 17.0 |
16390 | 2023-05-18 17:30:47 | MASTER-Amur | (00h 22m 34.20s , +27d 54m 50.2s) | C | 180 | 16.8 |
16789 | 2023-05-18 17:37:26 | MASTER-Amur | (00h 04m 00.08s , +27d 48m 45.4s) | C | 180 | 16.8 |
16989 | 2023-05-18 17:40:46 | MASTER-Amur | (00h 03m 57.56s , +27d 50m 06.1s) | C | 180 | 16.8 |
17189 | 2023-05-18 17:44:06 | MASTER-Amur | (00h 03m 57.25s , +27d 48m 30.8s) | C | 180 | 16.7 |
17875 | 2023-05-18 17:55:33 | MASTER-Amur | (23h 30m 51.84s , +24d 05m 05.7s) | C | 180 | 16.9 |
18075 | 2023-05-18 17:58:52 | MASTER-Amur | (23h 39m 33.41s , +24d 04m 17.8s) | C | 180 | 16.6 |
18280 | 2023-05-18 18:02:18 | MASTER-Amur | (00h 13m 26.48s , +27d 53m 29.6s) | C | 180 | 15.9 |
18480 | 2023-05-18 18:05:37 | MASTER-Amur | (00h 22m 26.18s , +27d 54m 42.7s) | C | 180 | 15.8 |
18679 | 2023-05-18 18:08:57 | MASTER-Amur | (23h 55m 59.05s , +29d 47m 58.1s) | C | 180 | 16.0 |
18879 | 2023-05-18 18:12:17 | MASTER-Amur | (00h 05m 53.80s , +29d 47m 33.9s) | C | 180 | 15.8 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 33824
Subject
LIGO/Virgo S230518h: Swift XRT observations, 8 X-ray sources
Date
2023-05-19T10:44:27Z (2 years ago)
From
P.A. Evans at U. Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P.
Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL),
S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), P. D'Avanzo (INAF-OAB), R.A.J.
Eyles-Ferris (U. Leicester), C. Gronwall (PSU), D. Hartmann (U. Clemson), N.J.
Klingler (NASA/GSFC), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E.
Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R. Oates (U.
Birmingham), P.T. O'Brien (U. Leicester), J.P.Osborne (U. Leicster), K.L. Page
(U.Leicester), M.J.Page (UCL-MSSL), B. Sbarufatti (INAF-OAB), M.H. Siegel (PSU),
G. Tagliaferri (INAF-OAB), E. Troja (U Tor Vergata, INAF) report on behalf of
the Swift team:
Swift has carried out 60 observations of the LVC error region for the GW trigger
S230518h convolved with the 2MPZ catalogue (Bilicki et al. 2014, ApJS, 210, 9),
using the 'BAYESTAR' GW localisation map. As this is a 3D skymap, galaxy
distances were taken into account in selecting which ones to observe. The
observations currently span from 7.8 ks to 35 ks after the LVC trigger, and
the XRT has covered 6.0 deg^2 on the sky (corrected for overlaps). This covers
1% of the probability in the 'ligo-skymap-from-samples' skymap, and 4.7% after
convolving with the 2MPZ galaxy catalogue, as described by Evans et al. (2016,
MNRAS, 462, 1591). These pointings and associated metadata have been reported to
the Treasure Map.
In total, we have detected 8 X-ray sources. Each source is assigned a rank of
1-4 which describes how likely it is to be related to the GW trigger, with 1
being the most likely and 4 being the least likely. The ranks are described at
https://www.swift.ac.uk/ranks.php.
We have found:
* 0 sources of rank 1
* 1 source of rank 2
* 1 source of rank 3
* 6 sources of rank 4
The 'rank 2' source was identified as such because it is uncatalogued in X-rays, and in
the initial analysis its flux was found to be significantly above the upper-limit from
the ROSAT All Sky Survey. However, this assumes a standard spectral model; using a model
fitted to the data from source 2 for this conversion we find that the XRT observed flux
is consistent with the ROSAT non-detection and so cannot be identified as a transient.
Details of all of the detected sources, by rank, are given below. All
coordinates are in J2000.
RANK 2 sources
==============
These are uncatalogued X-ray sources, which in the inital X-ray analysis had fluxes above the
historical 3-sigma upper limits.
| Source ID | RA | Dec | Err90 |
| S230518h_X8 | 22h 19m 10.78s | -84d 49' 08.0" | 7.8" |
RANK 3 sources
==============
These are uncatalogued X-ray sources, however they are not brighter than
previous upper limits, so do not stand out as likely counterparts to the GW
trigger.
| Source ID | RA | Dec | Err90 |
| S230518h_X6 | 07h 46m 12.93s | -54d 02' 40.3" | 7.8" |
RANK 4 sources
==============
These are catalogued X-ray sources, showing no signs of outburst compared to
previous observations, so they are not likely to be related to the GW trigger.
| Source ID | RA | Dec | Err90 |
| S230518h_X1 | 20h 40m 07.33s | -71d 15' 02.7" | 4.6" |
| S230518h_X2 | 20h 41m 59.36s | -73d 19' 09.5" | 7.7" |
| S230518h_X3 | 20h 02m 16.15s | -83d 26' 41.9" | 6.3" |
| S230518h_X4 | 07h 45m 07.88s | -54d 04' 50.7" | 17.1" |
| S230518h_X5 | 07h 45m 09.54s | -54d 05' 45.3" | 15.4" |
| S230518h_X7 | 07h 02m 12.02s | -86d 43' 48.3" | 6.7" |
For all flux conversions and comparisons with catalogues and upper limits from
other missions, we assumed a power-law spectrum with NH=3x10^20 cm^-2, and
photon index (Gamma)=1.7
The results of the XRT automated analysis, including details of the sources
listed above, are online at https://www.swift.ac.uk/LVC/S230518h
This circular is an official product of the Swift XRT team.
GCN Circular 33826
Subject
LIGO/Virgo S230518h: AGILE/MCAL observations
Date
2023-05-19T11:54:04Z (2 years ago)
From
Francesco Verrecchia at SSDC,INAF-OAR <francesco.verrecchia@ssdc.asi.it>
F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ.
Roma Tor Vergata), A. Ursi (ASI), C. Pittori (SSDC, and INAF/OAR),
M. Cardillo, C. Casentini, L. Foffano, G. Piano (INAF/IAPS), F.
Lucarelli (SSDC, and INAF/OAR), L. Baroncelli, A. Bulgarelli, A.
Ciabattoni, A. Di Piano, V. Fioretti, G. Panebianco, 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 S230518h at T0 = 2023-05-18
12:59:08.167 (UT), a preliminary analysis of the AGILE minicalorimeter
(MCAL) triggered data found no significant event candidates within
a time interval covering -/+ 2 sec from the LIGO/Virgo T0.
At the T0, about 25% of the S230518h 90% c.l. localization region
(LR) was accessible to the AGILE/MCAL.
Three-sigma upper limits (ULs) are obtained in the 0.4-1 MeV energy
range, for a 1 s integration time at different celestial positions
within the accessible S230518h LR, from a minimum of 1.4E-06 erg
cm^-2 to a maximum of 6.6E-06 erg cm^-2 (assuming as spectral model
a single power-law with photon index 1.5).
An independent procedure based on photon counting statistics
provides UL fluences in the range 0.4-1 MeV, for a 300 microseconds
integration time, from a minimum of 1.1E-08 erg cm^-2 to a maximum
of 4.4E-08 erg cm^-2.
We notice the detection of a short pulse in the energy range 0.4-1.4
MeV with S/N 5.7 at time T0+10.77 s.
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.