//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27997 SUBJECT: IceCube-200620A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 20/06/20 05:57:26 GMT FROM: Marcos Santander at U. Alabama/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2020-06-20 at 03:03:32.282 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Bronze alert stream. The threshold astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 2.321 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/134207_33533447.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2020-06-20 Time: 03:03:32.28 UT RA: 162.11 (+0.64 -0.95 deg 90% PSF containment) J2000 Dec: 11.95 (+0.63 -0.48 deg 90% PSF containment) J2000 We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. There are no Fermi 4FGL or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J1041.0+1342 at RA: 160.27 deg, Dec: 13.71 deg (J2000), 2.51 deg away from the best-fit event position. 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 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28001 SUBJECT: IceCube Alert 200620.13: Global MASTER-Net observations report DATE: 20/06/20 17:13:09 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs 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, D. Cheryasov (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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the IceCube Alert 200620.13 (trigger No 33533447,10h 48m 26.40s , +11d 57m 00.0s, R=0.68) errorbox 48529 sec after notice time and 48560 sec after trigger time at 2020-06-20 16:32:52 UT, with upper limit up to 18.4 mag. Observations started at twilight. The observations began at zenith distance = 46 deg. The sun altitude is -10.7 deg. The galactic latitude b = 58 deg., longitude l = 236 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1386385 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 48650 | 2020-06-20 16:32:52 | MASTER-SAAO | (10h 50m 30.09s , +12d 04m 20.6s) | C | 180 | 18.4 | 48650 | 2020-06-20 16:32:52 | MASTER-SAAO | (10h 43m 31.72s , +12d 03m 09.6s) | C | 180 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28002 SUBJECT: IceCube-200620A: No ANTARES neutrino counterpart DATE: 20/06/21 06:42:25 GMT FROM: Antoine Kouchner at ANTARES Collaboration Alexis Coleiro (APC/Universite de Paris) and Damien Dornic (CPPM/CNRS) on behalf of the ANTARES Collaboration.
Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported single track-like event IceCube-200620A (GCN 27997>). The original reconstructed origin was 31.9 degrees below the horizon for ANTARES.
No up-going muon neutrino candidate events were recorded in a 3 deg cone around the location of the IceCube event coordinates (accounting for the reported uncertainties) during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible all time.
This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of about 15 GeV.cm^-2 over the energy range 5 TeV –4 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and about 30 GeV.cm^-2 (810 GeV - 405 TeV) for an E^-2.5 spectrum. A search over an extended time window of +/- 1 day has also yielded no detection (44% visibility).
ANTARES > is the largest undersea neutrino detector (Mediterranean Sea) and it is primarily sensitive to astrophysical 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28004 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-200620A DATE: 20/06/21 12:27:44 GMT FROM: Simone Garrappa at DESY ** *S. Garrappa (DESY-Zeuthen) and S. Buson (Univ. of Wuerzburg) on behalf of the Fermi-LAT collaboration:* * We report an analysis of observations of the vicinity of the high-energy IC200620A neutrino event (GCN 27997) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2020-06-20 at 03:03:32.28 UT (T0) with J2000 position RA =162.11 (+0.64 -0.95) deg, Decl. = 11.95 (+0.63 -0.48) deg 90% PSF containment. No cataloged >100 MeV gamma-ray sources (The Fermi-LAT Collaboration 2019, arXiv:1902.10045) are located within the 90% IC200620A localization error. We searched for intermediate (days to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (> 5 sigma) new excess emission (> 100 MeV), at the IC200620A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IceCube best-fit position, the >100 MeV flux upper limit (95% confidence) is < 1.4e-10 ph cm^-2 s^-1 for ~11-years (2008-08-04 / 2020-06-20 UTC), < 1.7e-8 (< 1.6e-7) ph cm^-2 s^-1 for a 1-month (1-day) integration time before T0. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this source will continue. For these observations the Fermi-LAT contact persons are S. Garrappa (simone.garrappa at desy.de ) and S. Buson (sara.buson at uni-wuerzburg.de ). 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. * //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28005 SUBJECT: IceCube-200620A: One Candidate Counterpart from the Zwicky Transient Facility DATE: 20/06/21 19:16:19 GMT FROM: Simeon Reusch at DESY Simeon Reusch, Robert Stein and Anna Franckowiak (DESY) report: On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We observed the localization region of the neutrino event IceCube-200620A (Santander et. al, GCN 27997) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We started observations in the r-band beginning at 2020-06-21T04:49 UTC, approximately 25.8 hours after event time. We covered 1.2 sq deg, corresponding to 100.0% of the reported localization region (this estimate does not account for chip gaps). Each exposure was 300s with a typical depth of 21.0 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019). We are left with the following high-significance transient candidate by our pipeline, lying within the 90.0% localization of the skymap. +---------------------------------------------------------------------------------+ | ZTF Name | IAU Name | RA (deg) | DEC (deg) | Filter | Mag | MagErr | +---------------------------------------------------------------------------------+ | ZTF20abgvabi | AT 2020ncr | 162.5306820 | +12.1462203 | r | 20.67 | 0.10 | +---------------------------------------------------------------------------------+ AT 2020ncr has a faint host with a SDSS photometric redshift estimate of z=0.51 +/- 0.09. This would result in an estimated absolute magnitude of -21.7. There have been optical pre-detections up to 120 days prior to neutrino arrival time. As the nature of the transient is unclear, spectroscopic follow-up is recommended. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28006 SUBJECT: IceCube-200620A: not observable by Fermi-GBM DATE: 20/06/21 19:29:15 GMT FROM: Cori Fletcher at USRA C. Fletcher (USRA) reports on behalf of the Fermi-GBM team: At the time of the neutrino candidate IceCube-200620A (GCN 27997), Fermi was passing through the South Atlantic Anomaly from 17.6 minutes prior until 4.1 minutes after the trigger time; therefore the GBM detectors were disabled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28007 SUBJECT: IceCube-200620A: MASTER previous detection of ZTF20abgvabi/AT2020ncr DATE: 20/06/21 22:59:26 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, K.Zhirkov, 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), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), 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 (Irkutsk State University, API), A. Gabovich, Yu. Sergienko, V.Yurkov (Blagoveschensk Educational State University) MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) started IceCube-200620A inspection (The IceCube Collaboration GCN 27997) 8560 sec after trigger time at 2020-06-20 16:32:52 UT (Lipunov et al. GCN 28001, see cover map and error-box altitude at alert time and inspect time at https://master.sai.msu.ru/site/master2/observ.php?id=1386385 ) ZTF candidate ZTF20abgvabi/AT 2020ncr with RA,Dec(2000)=162.5306820 +12.1462203 (Reusch et al. GCN 28005) presents at MASTER archive images on 2015-12-25 (60s exposition). MASTER database (2006-2020) analysis will be continued. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28009 SUBJECT: IceCube-200620A: INTEGRAL was inactive at the time of the event DATE: 20/06/22 14:04:20 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) S. Mereghetti (INAF IASF-Milano, Italy) J. Rodi (IAPS-Roma, Italy) A. Coleiro (APC, France) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration The INTEGRAL spacecraft has a highly elliptical orbit and the instruments are not acquiring science data during perigee passage, every 2.6 days to prevent radiation-induced damages. Unfortunately, at the time of the IceCube-200620A (2020-06-20 03:03:32, GCN27997) the spacecraft was preparing to the start the observations after the perigee passage between the orbits number 2241 and 2242 and no scientific instrument data are available between 2020-06-19T22:20:06 and 2020-06-20T08:40:00. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28010 SUBJECT: IceCube-200620A: Upper limits from a search for additional neutrino events in IceCube DATE: 20/06/22 14:09:01 GMT FROM: Alex Pizzuto at ICECUBE/U of Wisconsin The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search for additional track-like muon neutrino events arriving from the direction of IceCube-200620A (https://gcn.gsfc.nasa.gov/gcn3/27997.gcn3) in a time range of 2 days centered on the alert event time (2020-06-19 03:03:32.28 UTC to 2020-06-21 03:03:32.28 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, one additional track-like event is found in spatial coincidence with the 90% containment region of IceCube-200620A. We find that these data are consistent with atmospheric background expectations, with a p-value of 1.0. We accordingly derive a time-integrated muon-neutrino flux upper limit at the alert position of E^2 dN/ dE = 4.0 x 10^-5 TeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are approximately between 1 TeV and 1 PeV. A subsequent search was performed to include the month of data prior to the alert event (2020-05-20 03:03:32.28 UTC to 2020-06-21 03:03:32.28 UTC). In this case, we report a p-value of 1.0, consistent with no significant excess of track-like events, and a corresponding time-integrated muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) of 6.6 x 10^-5 TeV cm^-2 at the 90% CL. 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28014 SUBJECT: IceCube-200620A: No significant detection in HAWC DATE: 20/06/23 13:37:01 GMT FROM: Hugo Ayala at Pennsylvania State University Hugo Ayala (Penn State) reports on behalf of the HAWC collaboration (http://www.hawc-observatory.org/collaboration): On 2020/06/20 03:03:32 UTC, the IceCube collaboration reported a track-like very-high-energy event that has a high probability of being an astrophysical neutrino, IceCube-200620A. Location is at RA: 162.11 (+0.64/-0.95 deg 90% PSF containment) J2000 Dec: 11.95 (+0.63/-0.48 deg 90% PSF containment) J2000 (GCN circular 27997). We performed two types of analyses for the follow-up. The first is for a steady source in archival data and the second is a search for a transient source. We assume a power-law spectrum with an index of -2.3 for both analyses. Search for a steady source in archival data: The archival data spans from November 2014 to May 2018. We searched inside the reported IceCube error region. The most significant location, with p-value 2.17e-2 (1.79e-1 post-trials), is at RA 161.76 deg, Dec +12.02 deg (±0.26 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit on gamma rays at the maximum position of: E^2 dN/dE = 2.09e-13 (E/TeV)^-0.3 TeV.cm^-2.s^-1 Search for a transient source. Since the event was not in our field of view at the time reported, we report the combined result for the transits before and after the IceCube event. Data acquisition started on 2020/06/19 02:14:06 UTC and ended 2020/06/21 02:29:12 UTC. The most significant location, with p-value 1.99E-3 (1.77E-2 post-trials), is at RA 162.03 deg, Dec +11.38 deg (±0.46 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit at the position of maximum significance of: E^2 dN/dE = 9.05E-12 (E/TeV)^-0.3 TeV.cm^-2.s^-1 HAWC is a very-high-energy gamma-ray observatory operating in Central Mexico at latitude 19 deg. north. Operating day and night with over 95% duty cycle, HAWC has an instantaneous field of view of 2 sr and surveys 2/3 of the sky every day. It is sensitive to gamma rays from 300 GeV to 100 TeV.