//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33097 SUBJECT: IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 22/12/24 04:04:09 GMT FROM: Marcos Santander at U. Alabama/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2022-12-24 at 00:55:09.3 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 4.116 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/137469_77414913.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2022-12-24 Time: 00:55:09.3 UT RA: 335.74 (+1.01, -0.72 deg 90% PSF containment) J2000 Dec: 1.42 (+0.41, -0.30 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 of the event. The nearest gamma-ray source in either catalog is 4FGL J2223.3+0102 at RA: 335.85 deg, Dec: 1.05 deg J2000 (0.39 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: 33098 SUBJECT: IceCube Alert 221224.04: Global MASTER-Net observations report DATE: 22/12/24 19:39:09 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, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (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 221224.04 (trigger No 77414913,22h 23m 22.32s , +01d 23m 45.6s, R=0.51) errorbox 65572 sec after notice time and 65627 sec after trigger time at 2022-12-24 19:08:56 UT, with upper limit up to 15.2 mag. Observations started at twilight. The observations began at zenith distance = 70 deg. The sun altitude is -15.4 deg. The galactic latitude b = -45 deg., longitude l = 66 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2186854 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 65717 | 2022-12-24 19:08:56 | MASTER-SAAO | (22h 22m 46.59s , +01d 25m 49.9s) | C | 180 | 15.2 | 66100 | 2022-12-24 19:15:19 | MASTER-SAAO | (22h 22m 49.84s , +01d 26m 03.2s) | C | 180 | 13.9 | 66512 | 2022-12-24 19:22:10 | MASTER-SAAO | (22h 22m 56.22s , +01d 24m 18.8s) | C | 180 | 14.5 | 66723 | 2022-12-24 19:25:42 | MASTER-SAAO | (22h 23m 03.52s , +01d 24m 39.1s) | C | 180 | 12.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33102 SUBJECT: IceCube-221224A: BOOTES-4/MET Optical Upper Limit DATE: 22/12/25 16:31:57 GMT FROM: Dingrong Xiong at Yunnan Observatories of CAS, China D. R. Xiong, J. M. Bai, Y. F. Fan, K. Ye, C. J. Wang, Y. X. Xin, B. L. Lun, J. R. Mao, X. H. Zhao, L. Xu, X. G. Yu, K. X. Lu, X. Ding, D. Q. Wang (Yunnan Observatories), A. J. Castro-Tirado, E. Fernandez-Garcia, Y. D. Hu (IAA-CSIC) and C. J. Perez del Pulgar (UMA) on behalf of the BOOTES team report: On 22-12-24 at 00:55:09.3 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The nearest gamma-ray source 4FGL J2223.3+0102 is 0.39 deg away from the best-fit event position, but without localization of 90% uncertainty region of the event (GCN 33097). We observed the best-fit position of IceCube-221224A and the gamma-ray source 4FGL J2223.3+0102 with BOOTES-4/MET 0.6m automatic optical telescope. We did not detect any optical source within localizations of both them. The upper limits of magnitudes (without being corrected for Galactic extinction) are given as follows. Name | UT (start) | Upper Limits (3-sigma) | Exposure Time | Filter -------------------------------------------------------------------------------------------------------------- Best-fit position ofIceCube-221224A | 22-12-24T11:36:39.25 | 18.90 (0.05) | 5*60s | Clear 4FGL J2223.3+0102| 2022-11-24T12:06:12.63 | 18.20 (0.04) | 10*60s | SDSS-i --------------------------------------------------------------------------------------------------------------- The Burst Optical Observer and Transient Exploring System (BOOTES) is a world-wide automatic telescope network which aims to repaid follow-up of transient and astrophysical sources in the sky for which the first station was installed in 1998 (Hu et al. 2021). The fourth station of the BOOTES Network, BOOTES-4/MET, is located at the Lijiang Observatory of the Yunnan Observatories of China (Xiong et al. 2020). We acknowledge the support of these staffs from the BOOTES telescope networks. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33103 SUBJECT: Fermi-LAT gamma-ray observations of IceCube-221224A DATE: 22/12/25 22:26:03 GMT FROM: Simone Garrappa at DESY S. Garrappa (Ruhr-Universitaet Bochum), 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 IC221224A high-energy neutrino event (GCN 33097) 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 2022-12-24 at 00:55:09.3 UT (T0) with J2000 position RA = 335.74 (+1.01, -0.72) deg, Decl. = +1.42 (+0.41, -0.30) deg (90% PSF containment). No cataloged gamma-ray (>100 MeV; The Fermi-LAT collaboration 2022, ApJS, 260, 53) sources are located within the 90% IC221224A localization region. 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 IC221224A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC221224A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 5.8e-10 ph cm^-2 s^-1 for ~14-years (2008-08-04 to 2022-12-24 UTC), and < 7.1e-9 (<6.5e-8) 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 ruhr-uni-bochum.de), J. Sinapius (jonas.sinapius 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: 33118 SUBJECT: IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube DATE: 22/12/28 20:32:26 GMT FROM: Abhishek Desai 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-221224A (https://gcn.gsfc.nasa.gov/gcn3/33097.gcn3) in a time range of 1000 seconds centered on the alert event time (2022-12-24 00:46:49.291 UTC to 2022-12-24 01:03:29.291 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-221224A. 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-221224A 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 3e+02 GeV and 2e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2022-12-23 00:55:09.291 UTC to 2022-12-25 00:55:09.291 UTC). In this case, we report a p-value of 0.02, 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-221224A 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)