//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31678 SUBJECT: IceCube Alert 220304.74: Global MASTER-Net observations report DATE: 22/03/04 18:39:39 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), B.L.Carrasco, J.R.Valdes,V.Chavushyan, C.J.Martinez, V.M.Patino Alvarez, M.L.H.Rodriguez (INAOE, OAGH) 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) started inspect of the IceCube Alert 220304.74 (trigger No 4701751,03h 15m 19.20s , +04d 27m 50.4s, R=1.25) errorbox 399 sec after notice time and 452 sec after trigger time at 2022-03-04 17:51:44 UT, with upper limit up to 19.3 mag. Observations started at twilight. The observations began at zenith distance = 54 deg. The sun altitude is -9.4 deg. The galactic latitude b = -42 deg., longitude l = 177 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1902082 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 478 | 2022-03-04 17:51:44 | MASTER-SAAO | (03h 15m 25.92s , +04d 21m 56.3s) | C | 50 | 16.4 | 618 | 2022-03-04 17:51:44 | MASTER-SAAO | (03h 15m 25.92s , +04d 21m 56.3s) | C | 330 | 17.5 | Coadd 572 | 2022-03-04 17:52:54 | MASTER-SAAO | (03h 15m 22.53s , +04d 23m 34.3s) | C | 100 | 16.6 | 980 | 2022-03-04 17:59:02 | MASTER-SAAO | (03h 15m 17.23s , +04d 21m 55.3s) | C | 180 | 17.3 | 1180 | 2022-03-04 18:02:22 | MASTER-SAAO | (03h 15m 23.33s , +04d 22m 05.8s) | C | 180 | 17.9 | 1379 | 2022-03-04 18:05:41 | MASTER-SAAO | (03h 15m 19.93s , +04d 24m 00.7s) | C | 180 | 18.5 | 1579 | 2022-03-04 18:09:01 | MASTER-SAAO | (03h 15m 19.45s , +04d 22m 22.8s) | C | 180 | 18.8 | 1779 | 2022-03-04 18:12:20 | MASTER-SAAO | (03h 15m 21.63s , +04d 24m 10.7s) | C | 180 | 18.8 | 2083 | 2022-03-04 18:18:24 | MASTER-SAAO | (03h 14m 17.07s , +04d 54m 40.3s) | C | 60 | 17.4 | 2329 | 2022-03-04 18:22:30 | MASTER-SAAO | (03h 22m 21.30s , +04d 54m 46.9s) | C | 60 | 19.3 | 2408 | 2022-03-04 18:23:50 | MASTER-SAAO | (03h 13m 48.57s , +03d 01m 53.2s) | C | 60 | 19.1 | 2573 | 2022-03-04 18:26:34 | MASTER-SAAO | (03h 21m 56.33s , +03d 01m 52.0s) | C | 60 | 19.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31679 SUBJECT: IceCube-220304A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 22/03/04 18:57:39 GMT FROM: Erik Blaufuss at U. Maryland/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 4 March 2022 at 17:44:12.21 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 0.58 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/136388_4701751.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2022-03-04 Time: 17:44:12.21 UT RA: 48.78 (+7.68/-6.24 deg 90% PSF containment) J2000 Dec: 4.48 (+5.91/-4.96 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. Given the size of the 90% event containment region, many gamma-ray sources listed in the 4FGL-DR2 Fermi-LAT catalog are consistent with the best-fit candidate neutrino position. The sources 4FGL J0321.3+0425 is the closest, at 1.54 degrees from the best fit direction. The large uncertainty region arises from the partially-contained nature of this event, being detected at the edge of the IceCube instrumented volume. 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: 31701 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-220304A DATE: 22/03/06 22:17:12 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 IC220304A neutrino event (GCN 31679) with data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2022-03-04 17:44:12.21 UTC (T0) with J2000 position RA = 48.78 (+7.68, -6.24) deg, Decl. = 4.48 (+5.91, -4.96) deg 90% PSF containment. Several cataloged gamma-ray sources are found within the 90% IC220304A localization error (4FGL-DR3; arXiv:2201.11184; The Fermi-LAT collaboration 2020, ApJS, 247, 33). Based on a preliminary analysis of the LAT data over a 1-day integration time before T0, these sources are not significantly detected. Based on a preliminary analysis of the LAT data over a 1-month integration time before T0, two cataloged LAT sources within the 90% IC220304A localization error are significantly (>5 sigma) detected. One is 4FGL J0313.0+0229, located ~2 deg from the neutrino best-fit localization and associated with the blazar of uncertain type TXS 0310+022. This source is detected with an average monthly flux of  (1.1 +/- 0.2)e-7 ph cm^-2 s^-1 and photon index of 2.13 +/- 0.09. This flux value is ~20 times the value reported in the 4FGL-DR3, and the photon index is significantly smaller than the 4FGL-DR3 value of 2.48 +/- 0.08. An inspection of the one-month-binned light curve indicates that 4FGL J0313.0+0229 entered an elevated state roughly at the end of 2019 (also ATel#13463). The second object is the unidentified source 4FGL J0259.0+0552, located ~4.2 deg from the neutrino best-fit localization. The current average monthly flux is  (4 +/- 2)e-8 ph cm^-2 s^-1 (~10 times the 4FGL flux). The observed photon index of 2.1 +/- 0.2 is consistent with the 4FGL-DR3 value of 2.00 +/- 0.05. An inspection of the one-month-binned light curve of 4FGL J0259.0+0552 does not indicate any remarkable activity during the decade-long Fermi-LAT monitoring. We searched for the existence of intermediate (day to months) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (>5sigma) new excess emission within the IC220304A 90% confidence localization. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC220304A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 1.2e-10 ph cm^-2 s^-1 for ~13-years (2008-08-04 to 2022-03-04 UTC), <1.2e-8 (< 1.8e-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. 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: 31708 SUBJECT: IceCube-220304A: Upper limits from a search for additional neutrino events in IceCube DATE: 22/03/08 15:13:52 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-220304A (https://gcn.gsfc.nasa.gov/gcn3/31679.gcn3) in a time range of 1000 seconds centered on the alert event time (2022-03-04 17:35:52.210 UTC to 2022-03-04 17:52:32.210 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-220304A. 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-220304A ranges from 1.3e-01 to 1.5e-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 (2022-03-03 17:44:12.210 UTC to 2022-03-05 17:44:12.210 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-220304A ranges from 1.5e-01 to 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)