//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33402 SUBJECT: IceCube Alert 230306.46: Global MASTER-Net observations report DATE: 23/03/06 11:39:12 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-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the IceCube Alert 230306.46 (trigger No 79205800,04h 50m 20.40s , +34d 05m 16.8s, R=0.51) errorbox 917 sec after notice time and 973 sec after trigger time at 2023-03-06 11:15:43 UT, with upper limit up to 14.3 mag. The observations began at zenith distance = 25 deg. The sun altitude is -19.4 deg. The galactic latitude b = -6 deg., longitude l = 169 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2202545 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1063 | 2023-03-06 11:15:43 | MASTER-Amur | (04h 51m 23.50s , +34d 09m 54.7s) | P\ | 180 | 13.2 | 1662 | 2023-03-06 11:25:41 | MASTER-Amur | (04h 51m 22.01s , +34d 08m 43.1s) | P\ | 180 | 12.0 | 1786 | 2023-03-06 11:29:01 | MASTER-Amur | (04h 51m 21.02s , +34d 08m 01.8s) | C | 30 | 14.3 | 1887 | 2023-03-06 11:30:42 | MASTER-Amur | (04h 51m 19.07s , +34d 09m 42.4s) | C | 30 | 14.0 | 1939 | 2023-03-06 11:31:33 | MASTER-Amur | (04h 51m 25.95s , +34d 09m 05.1s) | C | 30 | 14.1 | 1990 | 2023-03-06 11:32:24 | MASTER-Amur | (04h 51m 18.96s , +34d 08m 02.1s) | C | 30 | 14.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33403 SUBJECT: IceCube-230306A - IceCube observation of a high-energy neutrino candidate DATE: 23/03/06 13:31:19 GMT FROM: Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2023-03-06 at 10:59:30.41 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 0.71 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/137711_79205800.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2023-03-06 Time: 10:59:30.41 UT RA: 72.86 (+0.87/-0.89 deg 90% PSF containment) J2000 Dec: +34.23 (+0.87/-0.86 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 J0444.6+3425 at RA: 71.16 deg, Dec: 34.42 deg (1.42 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: 33408 SUBJECT: Fermi-LAT gamma-ray observations of IceCube-230306A DATE: 23/03/07 17:46:03 GMT FROM: Sara Buson at GSFC/Fermi J. Sinapius (DESY-Zeuthen), S. Garrappa (Ruhr-Universitaet Bochum) and S. Buson (Univ. of Wuerzburg) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the IC230306A high-energy neutrino event (GCN 33403) 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 2023-03-06 at 10:59:30.41 UT (T0) with J2000 position RA = 72.86 (+0.87, -0.89) deg, Decl. = +34.23 (+0.87, -0.86) deg (90% PSF containment). No cataloged gamma-ray (>100 MeV; The Fermi-LAT collaboration 2022, ApJS, 260, 53) sources are located within the 90% IC230306A 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 IC230306A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC230306A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 4.8e-10 ph cm^-2 s^-1 for ~14-years (2008-08-04 to 2023-03-06 UTC), and < 8.8e-9 (<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 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: 33409 SUBJECT: IceCube-230306A: Upper limits from a search for additional neutrino events in IceCube DATE: 23/03/07 19:57:15 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison 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-230306A (https://gcn.gsfc.nasa.gov/gcn3/33403.gcn3) in a time range of 1000 seconds centered on the alert event time (2023-03-06 10:51:10.410 UTC to 2023-03-06 11:07:50.410 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-230306A. 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-230306A 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 6e+04 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2023-03-05 10:59:30.410 UTC to 2023-03-07 10:59:30.410 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-230306A 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)