//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27719 SUBJECT: IceCube-200512A: IceCube observation of a high-energy neutrino candidate event DATE: 20/05/12 10:58:22 GMT FROM: Cristina Lagunas Gualda at DESY The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 20/05/12 at 07:31:27.76 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 average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 2.61 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/134081_58268464.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 20/05/12 Time: 07:31:27.76 UT RA: 295.18 (+1.72 -2.26 deg 90% PSF containment) J2000 Dec: 15.79 (+1.26 -1.29 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 4FGL sources inside the 90% localization region. The closest source is 4FGL J1947.1+1729 located at RA 296.78 deg and dec 17.49 deg (at a distance of 2.28 degrees from the best-fit location). 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: 27720 SUBJECT: IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation DATE: 20/05/12 11:58:03 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve 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 IceCube-200512A (GCN 27719). At the time of the event (2020-05-12 07:31:27 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 137 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (2.8% of optimal) response of ISGRI, somewhat suppressed (55% of optimal) response of IBIS/Veto, and strongly suppressed (36% 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]) data. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 4.9e-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 ~4.6e-07 (1.2e-07) 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: 1 tentatively associated excess: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -0.501 | 0.35 | 3.7 | 1 +/- 0.302 +/- 0.488 | 0.00748 1 possibly associated excess: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -4.13 | 0.9 | 3.7 | 0.651 +/- 0.188 +/- 0.317 | 0.0214 3 likely background excesses: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -81.8 | 2.1 | 3.7 | 0.434 +/- 0.123 +/- 0.211 | 0.179 23.4 | 0.25 | 3.3 | 1.1 +/- 0.357 +/- 0.536 | 0.937 -190 | 0.5 | 4.2 | 0.987 +/- 0.252 +/- 0.481 | 0.955 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. [1] Savchenko et al. 2017, A&A 603, A46 [2] Savchenko et al. 2012, A&A 541A, 122S //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27721 SUBJECT: IceCube-200512A: No Candidate Counterparts from the Zwicky Transient Facility DATE: 20/05/12 16:47:47 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-200512A (Lagunas et. al, GCN 27719) 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 g-band and r-band beginning at 2020-05-12T09:16:17.700 UTC, approximately 1.7 hours after event time. We covered 9.3 sq deg, corresponding to 99.1% of the reported localization region. This estimate accounts 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). No promising source candidates were identified. We note that the reported neutrino localization region lies at low galactic latitude. Given the high galactic extinction, our search was not sensitive to extragalactic objects. Observations of this region will continue as part of routine survey operations. 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: 27722 SUBJECT: IceCube Alert 200512.31: Global MASTER-Net observations report DATE: 20/05/12 18:13:10 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-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 IceCube Alert 200512.31 (trigger No 58268464,19h 40m 43.20s , +15d 47m 24.0s, R=1.63) errorbox 36576 sec after notice time and 36627 sec after trigger time at 2020-05-12 17:41:54 UT, with upper limit up to 12.3 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -15.5 deg. The galactic latitude b = -4 deg., longitude l = 53 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1354761 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 36657 | 2020-05-12 17:41:54 | MASTER-Amur | (19h 46m 28.62s , +16d 07m 15.7s) | C | 60 | 12.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27723 SUBJECT: IceCube-200512A: not observable by Fermi-GBM DATE: 20/05/12 18:26:17 GMT FROM: Christian Malacaria at NASA-MSFC/USRA At the time of IceCube-200512A (GCN 27719), Fermi was passing through the South Atlantic Anomaly from 7.5 minutes prior until 13.3 minutes after the trigger time; therefore the GBM detectors were disabled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27725 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-200512A DATE: 20/05/12 20:04:05 GMT FROM: Sara Buson at GSFC/Fermi S. Buson (Univ. of Wuerzburg) and S. Garrappa (DESY-Zeuthen) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC200512A neutrino event (GCN 27719) 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 2020-05-12 07:31:27.75 UT (T0) with J2000 position RA = 295.18 (+1.72, -2.26) deg, Decl. = 15.79 (+1.26, -1.29) deg 90% PSF containment. No cataloged >100 MeV gamma-ray sources are located within the 90% IC200512A localization error. We searched for the existence of intermediate (months to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (>5sigma) new excess emission (> 100 MeV) within the IC200512A 90% confidence localization. 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 < 7e-10 ph cm^-2 s^-1 for ~11-years (2008-08-04 / 2020-05-12 UTC), < 9e-9 (< 1e-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 this source the Fermi-LAT contact persons are S. Buson (sara.buson at uni-wuerzburg.de) and S. Garrappa (simone.garrappa at desy.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: 27732 SUBJECT: IceCube-200512A: Upper limits from a search for additional neutrino events in IceCube DATE: 20/05/13 20:37:06 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-200512A (https://gcn.gsfc.nasa.gov/gcn3/27719.gcn3) in a time range of 2 days centered on the alert event time (2020-05-11 07:31:27.750 UTC to 2020-05-13 07:31:27.750 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, two additional track-like events are found in spatial coincidence with the 90% containment region of IceCube-200512A. 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 = 4.1 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 (2020-04-12 07:31:27.750 UTC to 2020-05-13 07:31:27.750 UTC). In this case, we report a p-value of 0.05, 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 9.4 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.