//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31241 SUBJECT: IceCube-211216A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 21/12/16 10:16:16 GMT FROM: Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2021-12-16 at 07:07:38.13 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 2.37 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/136055_348073.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2021-12-16 Time: 07:07:38.13 RA: 316.05 (+2.58/-1.95 deg 90% PSF containment) J2000 Dec: 15.79 (+1.29/-1.63 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. Two gamma-ray sources listed in the 4FGL Fermi-LAT catalog are located in the 90% containment region. The sources are 4FGL J2100.0+1445 at RA: 315.02 deg, Dec: 14.76 deg (1.43 deg away from the best-fit event position) and 4FGL J2108.5+1434 at RA: 317.15, Dec: 14.58 (1.61 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: 31243 SUBJECT: IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation DATE: 21/12/16 13:03:57 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-211216A (GCN 31241). At the time of the event (2021-12-16 07:07:38 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 153 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (2.7% of optimal) response of ISGRI, somewhat suppressed (54% of optimal) response of IBIS/Veto, and somewhat suppressed (44% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was somewhat unstable (excess variance 1.8). 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 3.9e-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 ~3.9e-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 0.0226 | 0.7 | 3.4 | 0.521 +/- 0.15 +/- 0.13 | 0.00936 1 possibly associated excess: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP 0.748 | 0.05 | 3.7 | 2.23 +/- 0.571 +/- 0.557 | 0.0466 3 likely background excesses: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -14.9 | 1.15 | 3.4 | 0.405 +/- 0.117 +/- 0.101 | 0.126 -159 | 3.3 | 3.2 | 2.14 +/- 0.687 +/- 0.536 | 0.645 220 | 0.75 | 4.2 | 0.613 +/- 0.145 +/- 0.153 | 0.736 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. We note that combination of two low-FAP excesses (at T0+0.02s and T0+0.74s) is unusual, but accurate assessment of the chance of this coincidence would require much more detailed analysis. 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: 31245 SUBJECT: IceCube Alert 211216.30: Global MASTER-Net observations report DATE: 21/12/16 15:13:06 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (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), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the IceCube Alert 211216.30 (trigger No 348073,21h 05m 28.32s , +15d 55m 01.2s, R=0.55) errorbox 27392 sec after notice time and 27507 sec after trigger time at 2021-12-16 14:46:05 UT, with upper limit up to 16.6 mag. Observations started at twilight. The observations began at zenith distance = 39 deg. The sun altitude is -12.2 deg. The galactic latitude b = -21 deg., longitude l = 65 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1816191 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 27598 | 2021-12-16 14:46:05 | MASTER-Kislovodsk | (21h 05m 47.09s , +15d 56m 54.7s) | C | 180 | 16.6 | 27598 | 2021-12-16 14:46:05 | MASTER-Kislovodsk | (21h 05m 31.20s , +16d 19m 48.2s) | C | 180 | 15.6 | 28187 | 2021-12-16 14:56:54 | MASTER-Kislovodsk | (21h 08m 10.18s , +16d 25m 54.5s) | C | 60 | 15.7 | 28187 | 2021-12-16 14:56:54 | MASTER-Kislovodsk | (21h 03m 34.62s , +16d 48m 26.1s) | C | 60 | 15.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31248 SUBJECT: IceCube Alert 211216.99: Global MASTER-Net observations report DATE: 21/12/17 00:13:06 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (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), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the IceCube Alert 211216.99 (trigger No 6147475,13h 18m 32.64s , +16d 54m 57.6s, R=0.51) errorbox 151 sec after notice time and 202 sec after trigger time at 2021-12-16 23:44:36 UT, with upper limit up to 16.3 mag. The observations began at zenith distance = 68 deg. The sun altitude is -52.0 deg. The galactic latitude b = 77 deg., longitude l = 338 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1816964 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 223 | 2021-12-16 23:44:36 | MASTER-Kislovodsk | (13h 17m 51.05s , +17d 00m 52.2s) | P- | 40 | 15.2 | 1127 | 2021-12-16 23:58:30 | MASTER-Kislovodsk | (13h 17m 50.65s , +17d 01m 25.1s) | C | 180 | 16.3 | 1127 | 2021-12-16 23:58:30 | MASTER-Kislovodsk | (13h 17m 55.77s , +16d 38m 11.5s) | C | 180 | 16.1 | 1528 | 2021-12-17 00:05:12 | MASTER-Kislovodsk | (13h 17m 54.98s , +17d 01m 33.0s) | C | 180 | 16.1 | 1528 | 2021-12-17 00:05:12 | MASTER-Kislovodsk | (13h 18m 00.06s , +16d 38m 29.4s) | C | 180 | 15.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31252 SUBJECT: IceCube-211216A: No neutrino counterpart candidates in ANTARES search DATE: 21/12/17 09:28:31 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 track event IceCube-211216A (GCN #31241 ). At the time of the alert, the reconstructed origin was -8.4 degrees below the horizon for ANTARES. No up-going muon neutrino candidate events were recorded within the 90% error box of the IceCube event during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible from [T-60min, T+51min] (95%). This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 16 GeV.cm^-2 over the energy range 5 TeV – 5 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 49 GeV.cm^-2 (1 TeV - 450 TeV) for an E^-2.5 spectrum. A search over an extended time window of +/- 1 day has also yielded no detection (41% 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: 31254 SUBJECT: IceCube-211216A: Upper limits from a search for additional neutrino events in IceCube DATE: 21/12/17 17:49:02 GMT FROM: Alex Pizzuto at ICECUBE/U of Wisconsin The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-211216A (https://gcn.gsfc.nasa.gov/gcn3/31241.gcn3) in a time range of 1000 seconds centered on the alert event time (2021-12-16 06:59:18.130 UTC to 2021-12-16 07:15:58.130 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-211216A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-211216A is 1.4e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 2e+02 GeV and 1e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2021-12-15 07:07:38.130 UTC to 2021-12-17 07:07:38.130 UTC). In this case, we report a p-value of 1.00, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-211216A is 1.6e-01 GeV cm^-2 in a 2 day 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] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31255 SUBJECT: IceCube-211216A: Upper limits from Fermi-GBM Observations DATE: 21/12/18 00:21:25 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC) reports on behalf of the Fermi-GBM team: For the IceCube high-energy neutrino candidate event IceCube-211216A (GCN 31241), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 316.05 (+2.58/-1.95 deg 90% PSF containment) J2000 Dec: 15.79 (+1.29/-1.63 deg 90% PSF containment) J2000 There was no Fermi-GBM onboard trigger around the event time of the neutrino candidate. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around the neutrino candidate time. From this search, no significant signal was found related to IceCube-211216A. We set upper limits on impulsive gamma-ray emission. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------------- 0.128 s: 7.9 14. 23. 1.024 s: 2.1 4.1 9.3 8.192 s: 0.6 1.2 2.3 These results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31257 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-211216A DATE: 21/12/18 01:06:44 GMT FROM: Simone Garrappa at DESY S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and J. Sinapius (DESY-Zeuthen) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC211216A neutrino event (GCN 31241) 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 2021-12-16 07:07:38.13 UTC (T0) with J2000 position RA = 316.05 (+2.58, -1.95) deg, Decl. = 15.79 (+1.29, -1.63) deg 90% PSF containment. Two cataloged >100 MeV gamma-ray sources are located within the 90% IC211216A localization error. These are 4FGL J2100.0+1445 at a distance of roughly 1.5 deg and 4FGL J2108.5+1434 at a distance of roughly 1.6 deg (The Fourth Fermi-LAT catalog DR2; The Fermi-LAT collaboration 2020, ApJS, 247, 33). Based on a preliminary analysis of the LAT data over the 1-month timescale before T0, these objects are not significantly detected at gamma-rays. 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 (0.1 - 300 GeV) within the IC211216A 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 < 6.3e-10 ph cm^-2 s^-1 for ~13-years (2008-08-04 / 2021-12-16 UTC), < 4.2e-9 (< 2.3e-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 region 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: 31271 SUBJECT: IceCube-211216A: No significant detection in HAWC DATE: 21/12/21 20:54:47 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 2021/12/16 07:07:38.13 UTC, the IceCube collaboration reported a track-like very-high-energy event that has a high probability of being an astrophysical neutrino, IceCube-211216A. Location is at RA: 316.05 (+2.58/-1.95 deg 90% PSF containment) J2000 Dec: 15.74 (+1.29/-1.63 deg 90% PSF containment) J2000 (GCN circular 31241). 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 June 2019. We searched inside the reported IceCube error region. The most significant location, with p-value 2.5e-3 (1.5e-1 post-trials), is at RA 316.27 deg, Dec +15.33 deg (±0.7 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 = 1.33e-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 2021/12/15 18:23:07 UTC and ended 2021/12/17 01:00:21 UTC. The most significant location, with p-value 9.7e-4 (6.3e-2 post-trials), is at RA 318.38 deg, Dec +16.57 deg (±0.20 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit at the position of maximum significance of: E^2 dN/dE = 2.16e-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.