//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24854 SUBJECT: IceCube-190619A - IceCube observation of a high-energy neutrino candidate event DATE: 19/06/19 15:37:27 GMT FROM: Erik Blaufuss at U. Maryland/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 19/06/19 at 13:14:18.04 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Gold alert stream.  The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.98 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/132707_54984442.amon), more  sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 19/06/19 Time: 13:14:18.04 UT RA: 343.26 (+ 4.08 - 2.63 deg  90% PSF containment) J2000 Dec: 10.73 (+ 1.51 - 2.61 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 J2252.6+1245 at RA: 343.17 deg, Dec: 12.75 deg (2.73 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: 24856 SUBJECT: IceCube-190619A: not observable by Fermi-GBM DATE: 19/06/19 18:33:05 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood and C.A. Wilson-Hodge (NASA/MSFC) report on behalf of the Fermi-GBM Team. At the time of IceCube-190619A (GCN 24854), Fermi was passing through the South Atlantic Anomaly from 2 minutes prior to 14 minutes after the trigger time; therefore the GBM detectors were disabled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24858 SUBJECT: IceCube-190619A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation DATE: 19/06/20 08:54:29 GMT FROM: Alexis Coleiro at APC/U. Paris Diderot A. Coleiro (APC, France), F. Onori (IAPS-Roma, Italy) V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) J. Rodi (IAPS-Roma, Italy) S. Mereghetti (INAF IASF-Milano, Italy) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using combination of INTEGRAL all-sky detectors (following Savchenko et al. 2017, A&A 603, A46): SPI/ACS, IBIS/Veto, and IBIS, we have performed a search for a prompt gamma-ray counterpart of IceCube-190619A (GCN 24854). At the time of the event (2019-06-19 13:14:18 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 46 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (21% of optimal) response of ISGRI, somewhat suppressed (41% of optimal) response of IBIS/Veto, and near-optimal (79% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was rather stable (excess variance 1.2). We have performed a search for any impulsive events in INTEGRAL SPI-ACS (as described in Savchenko et al. 2012, A&A 541A, 122S), IBIS, and IBIS/Veto data. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 2e-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 ~1.7e-07 (6.7e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24864 SUBJECT: IceCube-190619A - HAWC follow-up DATE: 19/06/20 14:21:26 GMT FROM: Israel Martinez-Castellanos at UMD/HAWC Antonio Galván (IA-UNAM), Israel Martinez-Castellanos (UMD) and Ignacio Taboada (GaTech) report on behalf of the HAWC collaboration (http://www.hawc-observatory.org/collaboration/): On June 19, 2019, 13:14:18.04 UT, the IceCube collaboration reported a track-like very-high-energy event that has a high probability of being an astrophysical neutrino, IceCube-190619A, at RA 343.26 deg and Dec 10.73 deg, J2000 (GCN circular 24854). In HAWC's sky, the neutrino was at zenith of 26.44 deg and setting. We have searched for a steady source as well as a transient source. * Search for a steady source in archival data from November 2014 to May 2018. Assuming a spectral index of -2.3 we searched in a 4.08 degree circle around IceCube's reported location. The highest significance, 3.02 sigma, was at RA= 344.88 deg, Dec= 13.28 deg (J2000). Note that there are at least 200 trials in this search, so post-trials significance is lower. We set a time-integrated upper limit 95% CL on gamma rays of: E^2 dN/dE = 2.59e-13 (E/TeV)^-0.3 TeV cm^-2 s^-1 * Search for a transient source. We have studied the transit of the event in HAWC's field of view (start 2019/06/19 08:30:06 UTC / stop 2019/06/19 14:37:06 UTC). The most significant location, within 4.08 deg, is 3.44 sigma (RA = 338.93 deg, Dec = 9.99 deg, J2000). We set a time-integrated upper limit 95% CL on gamma rays of: E^2 dN/dE = 1.56e-11 (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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24865 SUBJECT: IceCube-190619A: IceCube additional correlated neutrino search: upper limits DATE: 19/06/20 16:07:04 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-190619A (https://gcn.gsfc.nasa.gov/gcn3/24854.gcn3) in a time range of 2 days centered on the alert event time (2019-06-18 13:14:18.04 UTC to 2019-06-20 13:14:18.04 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% PSF containment of IceCube-190619A. We find that these data are well described by atmospheric background expectations, with a p-value of 1.0. Accordingly, these data would represent a time-integrated muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) at the 90% CL of 4.4 x 10^-5 TeV cm^-2 for this observation period. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are between approximately 1 TeV and 2 PeV. A subsequent search was performed to include the previous month of data (2019-05-19 13:14:18.04 UTC to 2019-06-20 13:14:18.04 UTC). In this case, we report a p-value of 1.0, consistent with no significant excess of track events, and a corresponding time-integrated muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) at the 90% CL of 1.2 x 10^-4 TeV cm^-2. 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: 24866 SUBJECT: IceCube-190619A: No counterpart candidates in ANTARES data DATE: 19/06/20 20:09:26 GMT FROM: Damien Dornic at CPPM,France Alexis Coleiro (APC) and Damien Dornic (CPPM) report 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-190619A (GCN 24854). The reconstructed origin was 19 degrees below the horizon for ANTARES. No up-going muon neutrino candidate events were recorded within 3 degrees of the IceCube event coordinates during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible all time. A search over an extended time window of +/- 1 day has also yielded no detection (45% visibility). This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 13 GeV.cm^-2 over the energy range 3.9 TeV - 3.9 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 33 GeV.cm^-2 (720 GeV - 320 TeV) for an E^-2.5 spectrum. ANTARES is the largest neutrino detector installed in the 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: 24867 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-190619A DATE: 19/06/20 20:42:04 GMT FROM: Sara Buson at GSFC/Fermi A. Gokus (University of Wuerzburg/ECAP, DE) and S. Garrappa (DESY-Zeuthen, DE) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC190619A neutrino event (GCN 24854) 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 2019-06-19 13:14:18 UT (T0) with J2000 position RA =343.26 (+4.08 -2.63) deg, Decl. = 10.73 (+1.51 -2.61) deg 90% PSF containment. No cataloged gamma-ray sources are found within the 90% IC190619A 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 IC190619A 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 < 4.5e-10 ph cm^-2 s^-1 for ~10.8-years (2008-08-04 / 2019-06-19), < 3.10e-09 ph cm^-2 s^-1 for a 1-year integration time (2018-06-20 / 2019-06-19) and < 5.1e-8 ph cm^-2 s^-1 for a 1-day integration time (2019-06-18 15:00:00 / 2019-06-19 15:00:00). 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 Andrea Gokus (andrea.gokus@astro.uni-wuerzburg.de) and Simone 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: 24879 SUBJECT: IceCube-190619A: prompt emission upper limits from AstroSat-CZTI DATE: 19/06/25 05:39:37 GMT FROM: Varun Bhalerao at Indian Inst of Tech A. Anumarlapudi (IITB), Aarthy E. (PRL), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: We have carried a search for X-ray candidates in Astrosat CZTI data in a 1000 sec window around the trigger time of the ICECUBE event ICECUBE190619A (UTC 2019-06-19 13:14:18.040, GCN 24854). CZTI is a coded aperture mask instrument that has considerable effective area for about 29% of the entire sky, but is also sensitive to brighter transients from the entire sky. At the time of merger, Astrosat's nominal pointing is (RA=299.58, DEC=35.21), whcich is 46.53 deg away from the transient likely location (RA=343.26, Dec=10.73). At the time of event, the Earth-satellite-transient angle is 160.27, hence the transient is not occulted by Earth in the satellite's frame. CZTI data were de-trended to remove orbit-wise background variation. We then searched data from the four independent, identical quadrants to look for coincident spikes in the count rates. Searches were undertaken by binning the data in 0.1s, 1s, and 10s respectively. Statistical fluctuations in count rates were estimated by using data from 10 (+-5) neighbouring orbits. We selected confidence levels such that the probability of a false trigger in a 1000 sec window is 10^-4. We do not find any evidence for any hard X-ray transient in this window, in the CZTI energy range of 20-200 keV. We convert our count rates into flux by assuming that the source spectrum is a power law with alpha = -1.0. We use a detailed mass model of the satellite to calculate the instrument response in the direction of transient and calculate flux limit in that direction. We get the following upper limits for source flux in the 20-200 keV band as : 0.1 s: flux limit= 2.85 e-7 ergs/cm^2/s 1.0 s: flux limit= 9.5 e-7 ergs/cm^2/s 10.0 s: flux limit= 2.0 e-6 ergs/cm^2/s CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.