//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27533 SUBJECT: IceCube Alert 200410.97: Global MASTER-Net observations report DATE: 20/04/10 23:39:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (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 200410.97 (trigger No 24635982,16h 05m 03.84s , +11d 35m 06.0s, R=0.53) errorbox 20 sec after notice time and 73 sec after trigger time at 2020-04-10 23:21:08 UT, with upper limit up to 18.1 mag. The observations began at zenith distance = 33 deg. The sun altitude is -30.9 deg. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the IceCube Alert 200410.97 errorbox 38 sec after notice time and 90 sec after trigger time at 2020-04-10 23:21:26 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 36 deg. The sun altitude is -33.2 deg. The galactic latitude b = 42 deg., longitude l = 24 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1334069 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 78 | 2020-04-10 23:21:08 | MASTER-Kislovodsk | (16h 04m 40.56s , +11d 21m 05.6s) | P| | 10 | 16.6 | 103 | 2020-04-10 23:21:08 | MASTER-Kislovodsk | (16h 04m 40.56s , +11d 21m 05.6s) | P| | 60 | 17.5 | Coadd 78 | 2020-04-10 23:21:08 | MASTER-Kislovodsk | (16h 04m 22.32s , +11d 48m 56.6s) | P- | 10 | 16.3 | 103 | 2020-04-10 23:21:08 | MASTER-Kislovodsk | (16h 04m 22.32s , +11d 48m 56.6s) | P- | 60 | 17.3 | Coadd 101 | 2020-04-10 23:21:26 | MASTER-Tavrida | (16h 09m 40.08s , +11d 33m 24.2s) | C | 20 | 16.4 | 126 | 2020-04-10 23:21:26 | MASTER-Tavrida | (16h 09m 40.07s , +11d 33m 24.2s) | C | 70 | 17.1 | Coadd 113 | 2020-04-10 23:21:38 | MASTER-Kislovodsk | (16h 04m 40.52s , +11d 19m 40.8s) | P| | 20 | 17.0 | 113 | 2020-04-10 23:21:38 | MASTER-Kislovodsk | (16h 04m 22.24s , +11d 47m 31.2s) | P- | 20 | 16.8 | 141 | 2020-04-10 23:22:06 | MASTER-Tavrida | (16h 09m 34.93s , +11d 32m 54.8s) | C | 20 | 15.3 | 159 | 2020-04-10 23:22:19 | MASTER-Kislovodsk | (16h 04m 42.29s , +11d 21m 08.3s) | P| | 30 | 17.0 | 159 | 2020-04-10 23:22:19 | MASTER-Kislovodsk | (16h 04m 23.95s , +11d 48m 57.5s) | P- | 30 | 16.9 | 186 | 2020-04-10 23:22:46 | MASTER-Tavrida | (16h 09m 34.90s , +11d 33m 55.3s) | C | 30 | 16.8 | 214 | 2020-04-10 23:23:09 | MASTER-Kislovodsk | (16h 04m 36.52s , +11d 20m 21.4s) | P| | 40 | 17.2 | 269 | 2020-04-10 23:23:09 | MASTER-Kislovodsk | (16h 04m 36.52s , +11d 20m 21.4s) | P| | 150 | 18.1 | Coadd 214 | 2020-04-10 23:23:09 | MASTER-Kislovodsk | (16h 04m 18.13s , +11d 48m 09.8s) | P- | 40 | 17.1 | 269 | 2020-04-10 23:23:09 | MASTER-Kislovodsk | (16h 04m 18.13s , +11d 48m 09.8s) | P- | 150 | 18.0 | Coadd 242 | 2020-04-10 23:23:37 | MASTER-Tavrida | (16h 09m 39.91s , +11d 32m 55.5s) | C | 40 | 17.0 | 307 | 2020-04-10 23:23:37 | MASTER-Tavrida | (16h 09m 39.91s , +11d 32m 55.6s) | C | 170 | 17.6 | Coadd 280 | 2020-04-10 23:24:10 | MASTER-Kislovodsk | (16h 04m 37.24s , +11d 21m 22.4s) | P| | 50 | 17.5 | 280 | 2020-04-10 23:24:10 | MASTER-Kislovodsk | (16h 04m 18.80s , +11d 49m 09.7s) | P- | 50 | 17.4 | 312 | 2020-04-10 23:24:37 | MASTER-Tavrida | (16h 09m 34.12s , +11d 31m 56.0s) | C | 60 | 17.0 | 355 | 2020-04-10 23:25:20 | MASTER-Kislovodsk | (16h 04m 42.28s , +11d 20m 23.6s) | P| | 60 | 17.5 | 355 | 2020-04-10 23:25:20 | MASTER-Kislovodsk | (16h 04m 23.79s , +11d 48m 10.0s) | P- | 60 | 17.4 | 398 | 2020-04-10 23:25:58 | MASTER-Tavrida | (16h 09m 40.59s , +11d 32m 04.0s) | C | 70 | 16.9 | 446 | 2020-04-10 23:26:41 | MASTER-Kislovodsk | (16h 04m 36.54s , +11d 19m 25.2s) | P| | 80 | 17.6 | 446 | 2020-04-10 23:26:41 | MASTER-Kislovodsk | (16h 04m 18.00s , +11d 47m 11.0s) | P- | 80 | 17.6 | 498 | 2020-04-10 23:27:28 | MASTER-Tavrida | (16h 09m 37.00s , +11d 33m 49.3s) | C | 90 | 17.2 | 556 | 2020-04-10 23:28:21 | MASTER-Kislovodsk | (16h 04m 42.32s , +11d 19m 45.7s) | P| | 100 | 17.8 | 556 | 2020-04-10 23:28:21 | MASTER-Kislovodsk | (16h 04m 23.72s , +11d 47m 31.0s) | P- | 100 | 17.6 | 619 | 2020-04-10 23:29:19 | MASTER-Tavrida | (16h 09m 36.98s , +11d 32m 26.3s) | C | 110 | 17.0 | 687 | 2020-04-10 23:30:22 | MASTER-Kislovodsk | (16h 04m 40.63s , +11d 21m 10.2s) | P| | 120 | 17.9 | 687 | 2020-04-10 23:30:22 | MASTER-Kislovodsk | (16h 04m 21.93s , +11d 48m 54.7s) | P- | 120 | 17.8 | 764 | 2020-04-10 23:31:29 | MASTER-Tavrida | (16h 09m 40.24s , +11d 33m 53.8s) | C | 140 | 16.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27534 SUBJECT: IceCube-200410A - IceCube observation of a high-energy neutrino candidate event DATE: 20/04/11 01:03:32 GMT FROM: Robert Stein at DESY The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 20/04/10 at 23:19:55.49 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 2.55 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/133945_24635982.amon ), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 20/04/10 Time: 23:19:55.49 UT RA: 242.58 (+14.05 -13.35 deg 90% PSF containment) J2000 Dec: 11.61 (+7.87 -6.21 deg 90% PSF containment) J2000 This event had a topology with a short distance traversed through the detector, which makes it challenging to reconstruct. The 90% containment region reported by the reconstruction algorithms is thus significantly larger than average error contours. Due to the large localization uncertainty for this event, there are many Fermi 4FGL catalog sources in the 90% containment region, including 8 sources lying 5 degrees or less from the best-fit position. The closest is 4FGL J1608.7+1029, at RA: 242.18 deg, Dec: 10.49 deg (1.18 deg away from the best-fit event position). We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. 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: 27537 SUBJECT: IceCube-200410A: Possible associated excess in INTEGRAL SPI-ACS prompt observation DATE: 20/04/11 06:53:15 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF S. Mereghetti (INAF IASF-Milano, Italy), E. Bozzo, V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland), A. Martin-Carrillo (UCD, Ireland), J. Rodi, F.Onori (IAPS-Roma, Italy), A. Coleiro (APC, France) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed a search for a prompt gamma-ray counterpart of IceCube-200410A (GCN 27534). At the time of the event (2020-04-10 23:19:55 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 139 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (3.7% of optimal) response of ISGRI, near-optimal (72% of optimal) response of IBIS/Veto, and strongly suppressed (33% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was rather stable (excess variance 1.2). We have performed a search for any impulsive events in INTEGRAL SPI- ACS data (as described in [2]. On a timescale of 1s we found an event with S/N=4 and a false alarm probability of 0.0124, about 4 s before T0. Its properties are the following T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -4.09 | 1 | 4 | 0.728 +/- 0.209 +/- 0.393 | 0.0124 Besides this possible associated excess, we do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 5.2e-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 ~5e-07 (1.4e-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. 3 likely background excesses: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP 96.6 | 1.6 | 3.3 | 0.479 +/- 0.164 +/- 0.259 | 0.613 240 | 1.25 | 3.9 | 0.614 +/- 0.186 +/- 0.332 | 0.74 204 | 0.85 | 3.9 | 0.753 +/- 0.226 +/- 0.407 | 0.899 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. 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: 27541 SUBJECT: IceCube-200410A: Upper limits from Fermi-GBM Observations DATE: 20/04/11 14:34:35 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-200410A (GCN 27534), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 242.58 (+14.05 -13.35 deg 90% PSF containment) J2000 Dec: 11.61 (+7.87 -6.21 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-200410A. 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: 5.7 8.0 18. 1.024 s: 2.3 3.7 6.4 8.192 s: 0.7 1.1 1.9 These results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27544 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-200410A DATE: 20/04/11 23:23:10 GMT FROM: Simone Garrappa at DESY S. Garrappa (DESY-Zeuthen) and S. Buson (Univ. of Wuerzburg) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC200410A neutrino event (GCN 27534) 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 2020-04-10 at 23:19:55.49 UT (T0) with J2000 position RA = 242.58 (+14.05, -13.35) deg, Decl. = 11.61 (+7.87, -6.21) deg 90% PSF containment. Several cataloged >100 MeV gamma-ray sources (The Fermi-LAT Collaboration 2019, arXiv:1902.10045) are located within the 90% IC200410A localization error. Based on a preliminary analysis of the LAT data over the timescales of 1-day prior to T0, these objects are not significantly detected at gamma-rays. Two of these objects are significantly detected over the timescale of 1-month prior to T0, these are 4FGL J1548.3+1456 (associated with the BL Lac object NVSS J154824+145702) and 4FGL J1555.7+1111 (associated with the BL Lac object PG 1553+113). Based on a preliminary analysis at this timescale, both objects show a gamma-ray flux comparable to the catalog value. 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 (> 100 MeV) within the IC200410A 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 < 1e-8 (< 1e-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: 27552 SUBJECT: IceCube-200410A: Upper limits from a search for additional neutrino events in IceCube DATE: 20/04/12 14:59:06 GMT FROM: Alex Pizzuto at ICECUBE/U of Wisconsin The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search for additional track-like muon neutrino events arriving from the direction of IceCube-200410A (https://gcn.gsfc.nasa.gov/gcn3/27534.gcn3) in a time range of 2 days centered on the alert event time (2020-04-09 23:19:55.489 UTC to 2020-04-11 23:19:55.489 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero additional track-like events are found in spatial coincidence with the 90% containment region of IceCube-200410A. We accordingly derive a time-integrated muon-neutrino flux upper limit at the alert position of E^2 dN/ dE = 7.7 x 10^-5 TeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are approximately between 1 TeV and 1 PeV. A subsequent search was performed to include the month of data prior to the alert event (2020-03-11 23:19:55.489 UTC to 2020-04-11 23:19:55.489 UTC). In this case, we report a p-value of 1.0, consistent with no significant excess of track-like events, and a corresponding time-integrated muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) of 1.8 x 10^-4 TeV cm^-2 at the 90% CL. 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: 27562 SUBJECT: IceCube-200410A : Upper limits from Insight-HXMT/HE observations DATE: 20/04/13 03:11:36 GMT FROM: YaoGuang Zheng at IHEP Y. G. Zheng, C. Cai, Y. F. Du, W. C. Xue, Q. Luo, S. Xiao, Q. B. Yi, Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: Insight-HXMT was taking data normally around the trigger time (T0=2020-04-10T23:19:55.49 UTC) of this high-energy neutrino event (GCN #27534), which was monitored without any occultation by the Earth. Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are found in a search of the Insight-HXMT/HE raw light curves. Assuming the counterpart GRB with three typical GRB Band spectral models, two typical duration timescales(1 s, 10 s) coming from the position of this neutrino event, the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are reported below: Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV): 1s: 1.3e-07 erg cm^-2 10s: 6.1e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1s: 2.1e-07 erg cm^-2 10s: 9.6e-07 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1s: 5.4e-07 erg cm^-2 10s: 2.1e-06 erg cm^-2 Further analysis will be reported in the following circulars. All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (record energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27569 SUBJECT: IceCube-200410A: No significant detection in HAWC DATE: 20/04/13 17:36:00 GMT FROM: Hugo Ayala at Pennsylvania State University Hugo Ayala (PSU) reports on behalf of the HAWC collaboration (http://www.hawc-observatory.org/collaboration): On 2020/04/10 23:19:55 UTC, the IceCube collaboration reported a track-like very-high-energy event that has a high probability of being an astrophysical neutrino, IceCube-200410A. Location is at RA: 242.58 (+14.05/-13.35 deg 90% PSF containment) J2000 Dec: 11.61 (+7.87/-6.21 deg 90% PSF containment) J2000 (GCN circular 27534). 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 May 2018. We searched inside the reported IceCube error region. The highest significance, 4.06 sigma (1.66 post-trials), is at RA 247.42 deg, Dec +8.08 deg (+-0.11 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 = 1.94e-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 2020/04/09 12:22:11 UTC and ended 2020/04/DD 12:28:48 UTC. The most significant location, with 3.22 sigma (-0.57 post-trials), is at RA 241.44 deg, Dec +12.14 deg (+-0.12 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit at the position of maximum significance of: E^2 dN/dE = 1.01e-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.