//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30468 SUBJECT: IceCube-210717A: IceCube observation of a high-energy neutrino candidate track-like event DATE: 21/07/18 15:22:53 GMT FROM: Cristina Lagunas Gualda at DESY The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 21/07/17 at 15:45:19.48 UT IceCube detected a high-energy starting event [1]. The IceCube online selection did not identify this event as a Gold or Bronze starting track. However, based on advanced reconstructions performed offline, we identify this event as a potential astrophysical neutrino of interest to the community, given its topology and light deposition. Because the event was not identified as either Gold or Bronze, we do not currently report a false alert rate or signalness. The IceCube detector was in a normal operating state at the time of detection. Advanced reconstruction algorithms have been applied offline, with the direction estimated to be: Date: 21/07/17 Time: 15:45:19.48 UT RA: 46.49 (+ 2.40 - 2.57 deg 90% PSF containment) J2000 Dec: -1.34 (+ 2.63 - 3.41 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 is one Fermi-LAT 4FGL source inside the 90% localization region, 4FGL J0304.5-0054, located at RA 46.14 deg and Dec -0.91 deg (J2000), at a distance of 0.55 degrees from the best-fit location. The source is also listed in the Fermi 3FHL hard-spectrum source catalog. 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] The IceCube Collaboration, Phys. Rev. Lett. 113, 101101 (2014) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30471 SUBJECT: IceCube-210717A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation DATE: 21/07/19 17:08:21 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: Using combination of INTEGRAL all-sky detectors (following [1]): SPI/ACS, IBIS/Veto, and IBIS we have performed a search for a prompt gamma-ray counterpart of IceCube-210717A (GCN 30468). At the time of the event (2021-07-17 15:45:19 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 124 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (4.1% of optimal) response of ISGRI, strongly suppressed (29% of optimal) response of IBIS/Veto, and somewhat suppressed (58% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was very stable (excess variance 1.1). We have performed a search for any impulsive events in INTEGRAL SPI- ACS (as described in [2]), 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 3.1e-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 ~2.7e-07 (7.1e-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: 4 likely background excesses: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -32 | 0.15 | 4.1 | 1.12 +/- 0.291 +/- 0.491 | 0.596 -162 | 2.1 | 3.4 | 2.39 +/- 0.767 +/- 1.05 | 0.68 152 | 2 | 3.3 | 2.36 +/- 0.786 +/- 1.04 | 0.832 -149 | 0.35 | 4.4 | 0.768 +/- 0.189 +/- 0.338 | 0.966 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: 30473 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-210717A DATE: 21/07/20 17:49:04 GMT FROM: Simone Garrappa at DESY S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and R. de Menezes (Univ. of Sao Paulo, Univ. of Wuerzburg) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC210717A neutrino event (GCN 30468) 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 2021-07-17 at 15:45:19.48 UT (T0) with J2000 position RA = 46.49 (+ 2.40, - 2.57) deg, Decl. = -1.34 (+ 2.63, - 3.41) deg (90% PSF containment). Three cataloged gamma-ray (>100 MeV) sources are located within the 90% IC210717A localization region (4FGL-DR2, The Fermi-LAT collaboration 2020, ApJS, 247, 33). Based on a preliminary analysis of the LAT data over the timescale of 1-day and 1-month prior to T0, none of these objects is significantly detected (> 5 sigma). 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 IC210717A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC210717A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 1.2e-10 ph cm^-2 s^-1 for ~12-years (2008-08-04 to 2021-07-17 UTC), and < 1.4e-8 (< 1.0e-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.