//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28520 SUBJECT: IceCube-200929A: No Candidate Counterparts from the Zwicky Transient Facility DATE: 20/09/28 12:45:07 GMT FROM: Simeon Reusch at DESY Simeon Reusch (DESY), Robert Stein (DESY), Sven Weimann (Ruhr University Bochum) and Anna Franckowiak (DESY/Ruhr University Bochum) report: On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We observed the localization region of the neutrino event IceCube-200926A (Lagunas et al. GCN 28504) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019; Graham et al. 2019). We started observations in the r-band beginning at 2020-09-26 11:58 UTC, approximately 4.1 hours after event time. We covered 1.3 sq deg, corresponding to 89.5% of the reported localization region. This estimate accounts for chip gaps. Each exposure was 300s with a typical depth of 21.0 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019; Stein et al. 2020) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019). We are left with the following high-significance transient candidates by our pipeline, all lying within the 90.0% localization of the skymap. No counterpart candidates were detected. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering is performed with the AMPEL Follow-up Pipeline (Stein et al. 2020). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28529 SUBJECT: IceCube Alert 200929.74: Global MASTER-Net observations report DATE: 20/09/29 19:26:07 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), 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the IceCube Alert 200929.74 (trigger No 68615710,01h 56m 11.52s , +03d 04m 51.6s, R=0.51) errorbox 2654 sec after notice time and 2722 sec after trigger time at 2020-09-29 18:33:59 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 48 deg. The sun altitude is -37.6 deg. The galactic latitude b = -55 deg., longitude l = 154 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1452099 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 2812 | 2020-09-29 18:33:59 | MASTER-Tunka | (01h 55m 20.08s , +02d 47m 06.9s) | C | 180 | 18.2 | 3547 | 2020-09-29 18:46:13 | MASTER-Tunka | (01h 55m 19.91s , +02d 46m 12.9s) | C | 180 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28532 SUBJECT: IceCube-200929A: IceCube observation of a high-energy neutrino candidate event DATE: 20/09/29 21:32:42 GMT FROM: Cristina Lagunas Gualda at DESY The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 20/09/29 at 17:48:36.84 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 1.411 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/134552_68615710.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 20/09/29 Time: 17:48:36.84 UT RA: 29.53 (+ 0.53 - 0.53 deg 90% PSF containment) J2000 Dec: 3.47 (+ 0.71 - 0.35 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-LAT 4FGL or 3FHL sources inside the 90% localization region. The closest source is 4FGL J0152.6+0147 located at RA 28.16 deg and Dec 1.79 deg (J2000), at a distance of 2.17 degrees from the best-fit location. 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: 28535 SUBJECT: IceCube-200929A: No neutrino counterpart candidates in ANTARES search DATE: 20/09/30 18:13:26 GMT FROM: Antoine Kouchner at ANTARES Collaboration Alexis Coleiro (APC/Université de Paris) and Damien Dornic (CPPM/CNRS) on behalf of the ANTARES Collaboration. Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported single track-like event IceCube-200929A (GCN 28532 ). The reconstructed origin was -10 degrees below the horizon for ANTARES. No up-going muon neutrino candidate events were recorded within the 90% error box of the IceCube event during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible all time. This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 13 GeV.cm^-2 over the energy range 3 TeV - 4 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 45 GeV.cm^-2 (650 GeV- 340 TeV) for an E^-2.5 spectrum. A search over an extended time window of +/- 1 day has also yielded no detection (47% visibility). ANTARES is the largest undersea neutrino detector (Mediterranean Sea) and it is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28536 SUBJECT: IceCube-200929A: Upper limits from Fermi-GBM Observations DATE: 20/09/30 21:19:14 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-200929A (GCN 28532), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 29.53 (+0.53 -0.53 deg 90% PSF containment) J2000 Dec: 3.47 (+0.71 -0.35 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-200929A. 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: 5.6 9.7 16. 1.024 s: 2.2 3.7 7.0 8.192 s: 0.8 1.3 2.1 These results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28537 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-200929A DATE: 20/09/30 21:38:22 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 IC200929A neutrino event (GCN 28532) 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 2020-09-29 at 17:48:36.84 UT (T0) with J2000 position RA = 29.53 (+0.53, -0.53) deg, Decl. = 3.47 (+0.71, -0.35) deg 90% PSF containment. No cataloged >100 MeV gamma-ray sources (The Fourth Fermi-LAT catalog; The Fermi-LAT collaboration 2020, ApJS, 247, 33) are located within the 90% IC200929A localization error. 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 IC200929A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC200929A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 2.4e-10 ph cm^-2 s^-1 for ~12-years (2008-08-04 / 2020-09-29 UTC), < 1.2e-8 (< 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 these observations 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: 28541 SUBJECT: Swift-XRT observations of IceCube 200929A DATE: 20/10/01 16:07:37 GMT FROM: Timothee Gregoire at Penn State P.A. Evans (U. Leicester), J.A. Kennea (PSU), H. A. Ayala Solares (PSU), D.F. Cowen (PSU), J. DeLaunay (PSU), D. B. Fox (PSU), A. Keivani (Columbia U.), J.P. Osborne (U. Leicester), T. Gregoire (PSU) report: Swift observed the field of IceCube 200929A (GCN Circ. 28532) between 22:37:07 2020 September 29 and 00:11:03 on 2020 September 30, collecting a total of 1.4 ks of cleaned photon counting (PC) mode data. The observations used a 3-point tiling pattern with a radius of ~0.2 degrees. We found 1 X-ray source, as detailed below, which is a known X-ray source, consistent with catalogued fluxes. We therefore do not claim it as the likely counterpart to IceCube 200929A The 3-sigma upper limit in the field was in the range 9-10 x 10^-3 ct/sec. The detected source was: Source no: 1 RA (J2000): 28.84047 [degrees] = 01h 55m 21.71s Dec (J2000): +2.9565 [degrees] = +02d 57' 23.4" Error: +5.0 [arcsec, 90% conf. radius] Count rate (0.3-10 keV): 0.014 (+0.008, -0.006) ct s-1 Flux (0.3-10 keV): 5.8 (+3.5, -2.5) x 10-13 erg cm-2 s-1 Note: This is 9.57" from the SIMBAD object 1RXS J015522.1+025731 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28543 SUBJECT: IceCube-200929A: Upper limits from a search for additional neutrino events in IceCube DATE: 20/10/01 17:56:24 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-200929A (https://gcn.gsfc.nasa.gov/gcn3/28532.gcn3) in a time range of 2 days centered on the alert event time (2020-09-28 17:48:36.84 UTC to 2020-09-30 17:48:36.84 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, one additional track-like event is found in spatial coincidence with the 90% containment region of IceCube-200929A. We find that these data are consistent with atmospheric background expectations, with a p-value of 1.0. We accordingly derive a time-integrated muon-neutrino flux upper limit at the alert position of E^2 dN/ dE = 2.9 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 2 TeV and 5 PeV. A subsequent search was performed to include the month of data prior to the alert event (2020-08-30 17:48:36.84 UTC to 2020-09-30 17:48:36.84 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 3.6 x 10^-5 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: 28546 SUBJECT: IceCube-200929A: No significant detection in HAWC DATE: 20/10/01 23:27:45 GMT FROM: Hugo Ayala at Pennsylvania State University Hugo Ayala (Penn State) reports on behalf of the HAWC collaboration (http://www.hawc-observatory.org/collaboration): On 2020/09/29 17:48:36 UTC, the IceCube collaboration reported a track-like very-high-energy event that has a high probability of being an astrophysical neutrino, IceCube-200929A. Location is at RA: 29.53 (+ 0.53 - 0.53 deg 90% PSF containment) J2000 Dec: 3.47 (+ 0.71 - 0.35 deg 90% PSF containment) J2000 (GCN circular 28532). 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 June 2019. We searched inside the reported IceCube error region. The most significant location, with p-value 1.13e-01 (4.97e-01 post-trials), is at RA 29.44 deg, Dec +3.10 deg (±0.76 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 = 2.34e-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 2020/09/27 10:45:47 UTC and ended 2020/09/29 10:56:56 UTC. The most significant location, with p-value 8.85e-02 (4.12e-01 post-trials), is at RA 29.18 deg, Dec +3.40 deg (±0.24 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit at the position of maximum significance of: E^2 dN/dE = 6.73e-12 (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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28552 SUBJECT: IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation DATE: 20/10/03 12:09:34 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) J. Rodi (IAPS-Roma, Italy) A. Coleiro (APC, France) S. Mereghetti (INAF IASF-Milano, Italy) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using combination of INTEGRAL all-sky detectors (following [1]): SPI/ACS, IBIS/Veto, and IBIS we have performed a search for a prompt gamma-ray counterpart of IceCube-200929A (GCN 28532). At the time of the event (2020-09-29 17:48:36 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 58 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (12% of optimal) response of ISGRI, strongly suppressed (19% of optimal) response of IBIS/Veto, and somewhat suppressed (66% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was very stable (excess variance 1.2). We have performed a search for any impulsive events in INTEGRAL SPI- ACS (as described in [2]), IBIS, and IBIS/Veto data. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 2.5e-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 ~2.2e-07 (8.5e-08) 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. We find: 1 possibly associated excess: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP 160 | 5.55 | 5 | 1.89 +/- 0.341 +/- 0.436 | 0.0439 5 likely background excesses: T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP -183 | 2.1 | 4 | 2.33 +/- 0.556 +/- 0.537 | 0.28 -9.48 | 0.45 | 3.1 | 4.05 +/- 1.2 +/- 0.936 | 0.351 -15.7 | 0.15 | 3.9 | 0.856 +/- 0.21 +/- 0.197 | 0.397 7.67 | 0.05 | 3.6 | 1.4 +/- 0.367 +/- 0.323 | 0.662 -16.9 | 0.2 | 3.4 | 0.651 +/- 0.181 +/- 0.15 | 0.752 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: 28593 SUBJECT: IceCube-200929A: JCMT/SCUBA2 observations DATE: 20/10/09 18:57:54 GMT FROM: Yuji Urata at Nat. Central U. Y. Urata (NCU) and K. Huang (CYCU) We observed the field of IceCube-200929A (GCN 28532) using SCUAB-2 sub-millimeter continuum camera on the James Clerk Maxwell Telescope. The observation was started at 2020/10/03 07:56 UTC and SCUBA2 imaged the field centered at RA 29.53 deg Dec 3.47 deg with 50 arcmin diameter. No source was detected, with the RMS background noise being 4.6 mJy/beam at 850 microns and 152 mJy/beam at 450 microns. We thank staffs of East Asian Observatory.