//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33204 SUBJECT: IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 23/01/22 05:24:48 GMT FROM: Erik Blaufuss at U. Maryland/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2023-01-22 03:50:02.00 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 3.62 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/137571_16496893.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2023-01-22 Time: 03:50:02.00 UT RA:16.79 (+3.17 / -2.56 deg 90% PSF containment) J2000 Dec: +7.78 (+3.44 / -3.26 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 four known gamma-ray sources listed in the Fermi 4FGL catalog within the 90% uncertainty region of the event. The nearest one is 4FGL J0100.3+0745 (RA: 15.09 deg, Dec: 7.76 deg in J2000 coordinates), 1.68 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: 33205 SUBJECT: IceCube Alert 230122.16: Global MASTER-Net observations report DATE: 23/01/22 10:52:12 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) started inspect of the IceCube Alert 230122.16 (trigger No 16496893,01h 10m 41.76s , +08d 22m 51.6s, R=1.34) errorbox 24254 sec after notice time and 24304 sec after trigger time at 2023-01-22 10:35:06 UT, with upper limit up to 12.5 mag. The observations began at zenith distance = 48 deg. The sun altitude is -23.4 deg. The galactic latitude b = -54 deg., longitude l = 132 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2193659 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 24394 | 2023-01-22 10:35:06 | MASTER-Amur | (01h 14m 25.12s , +08d 23m 26.9s) | C | 180 | 12.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33212 SUBJECT: Fermi-LAT gamma-ray observations of IceCube-230122A DATE: 23/01/23 19:59:55 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 IC230122A high-energy neutrino event (GCN 33204) 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 2023-01-22 at 03:50:02.00 UT (T0) with J2000 position RA = 16.79 (+3.17, -2.56) deg, Decl. = +7.78 (+3.44, -3.26) deg (90% PSF containment). Five cataloged gamma-ray (>100 MeV; The Fermi-LAT collaboration 2022, ApJS, 260, 53) sources are located within the 90% IC230122A localization region. Based on a preliminary analysis of the LAT data over the timescales of 1-month prior to T0, one of these objects,  the source 4FGL J0100.3+0745 associated to the BL Lac object GB6 J0100+0745 (at 1.68 deg offset from the best-fit neutrino localisation), is detected at ~4 sigma level. The flux measured for the source, is however consistent with the average value measured in the 4FGL. 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 IC230122A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC230122A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 2.9e-10 ph cm^-2 s^-1 for ~14-years (2008-08-04 to 2023-01-22 UTC), and < 6.5e-9 (<1.4e-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: 33219 SUBJECT: IceCube-230122A: Upper limits from a search for additional neutrino events in IceCube DATE: 23/01/24 21:47:19 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-230122A (https://gcn.gsfc.nasa.gov/gcn3/33204.gcn3) in a time range of 1000 seconds centered on the alert event time (2023-01-22 03:41:42.000 UTC to 2023-01-22 03:58:22.000 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-230122A. 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-230122A ranges from 1.3e-01 to 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 (2023-01-21 03:50:02.000 UTC to 2023-01-23 03:50:02.000 UTC). In this case, we report a p-value of 0.17, 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-230122A 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33228 SUBJECT: IceCube-230122A: BOOTES-2/TELMA Optical Upper Limit DATE: 23/01/28 14:16:31 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 2023-01-22 03:50:02.00 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The nearest one is 4FGL J0100.3+0745 within the 90% uncertainty region of the event, 1.68 deg away from the best-fit event position (GCN 33204, 33212). We observed the BL Lac object 4FGL J0100.3+0745 and the best-fit position of IceCube-230122A with BOOTES-2/TELMA robotic telescope.The magnitudes were calculated using bright stars in the same frame and the SDSS DR16 catalogue as reference. We did not detect any optical source within the best-fit position, and also the optical counterpart of the 4FGL J0100.3+0745. The upper limits of magnitudes (without being corrected for Galactic extinction) are given as follows. Sources | Tmid-T0 (day) | UT (start) | Upper Limit (error) | Exposure Time | Filter -------------------------------------------------------------------------------------------------------------- Best-fit position | 0.764 | 23-01-22 22:10:44.8 | 18.79 (0.22) | 2*300s (co-added) | Clear 4FGL J0100.3+0745 | 0.699 | 23-01-22 20:36:22.3 | 19.51 (0.03) | 8*300s (co-added) | Clear --------------------------------------------------------------------------------------------------------------- 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 BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain). We acknowledge the support of these staffs from the BOOTES telescope networks.