//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21916 SUBJECT: IceCube-170922A - IceCube observation of a high-energy neutrino candidate event DATE: 17/09/23 01:09:26 GMT FROM: Erik Blaufuss at U. Maryland/IceCube Claudio Kopper (University of Alberta) and Erik Blaufuss (University of Maryland) report on behalf of the IceCube Collaboration (http://icecube.wisc.edu/). On 22 Sep, 2017 IceCube detected a track-like, very-high-energy event with a high probability of being of astrophysical origin. The event was identified by the Extremely High Energy (EHE) track event selection. The IceCube detector was in a normal operating state. EHE events typically have a neutrino interaction vertex that is outside the detector, produce a muon that traverses the detector volume, and have a high light level (a proxy for energy). After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon/50579430_130033.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 22 Sep, 2017 Time: 20:54:30.43 UTC RA: 77.43 deg (-0.80 deg/+1.30 deg 90% PSF containment) J2000 Dec: 5.72 deg (-0.40 deg/+0.70 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. 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: 21917 SUBJECT: INTEGRAL SPI-ACS observation of AMON IceCube-170922A DATE: 17/09/23 09:31:27 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve V. Savchenko, C. Ferrigno (ISDC, University of Geneva, CH), P. Ubertini, A. Bazzano, L. Natalucci (INAF IAPS-Roma, Italy), S. Mereghetti (INAF IASF-Milano, Italy), P. Laurent (CEA, Saclay, France), E. Kuulkers (ESTEC/ESA, The Netherlands) We have exploited INTEGRAL data to search for a prompt gamma-ray counterpart of the cosmic neutrino candidate AMON IceCube IceCube-170922A (GCN 21916). At the time of the event (2017-09-22 20:54:30.4 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The neutrino localization was at an angle of 111 deg with respect to the spacecraft pointing axis. For this orientation the best sensitivity is achieved by SPI-ACS or IBIS/Veto, depending on the GRB spectrum and duration. The orientation was not optimal for INTEGRAL observation. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 2.8x10^-7 erg/cm^2 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=500 keV) occurring at any time in the interval +-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 7.8x10^-7 erg/cm^2/s 8 s time scale in 75-2000 keV energy range. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21923 SUBJECT: Search for counterpart to IceCube-170922A with ANTARES DATE: 17/09/24 19:34:55 GMT FROM: Damien Dornic at CPPM,France D. Dornic (CPPM/CNRS), A. Coleiro (APC/Universite Paris Diderot) on behalf of the ANTARES Collaboration: Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported single high-energy (EHE) neutrino IceCube-170922A (AMON IceCube EHE 50579430_130033). The reconstructed origin was 14.2 degrees below the horizon for ANTARES. No up-going muon neutrino candidate events were recorded within three degrees of the IceCube event coordinates during a +/- 1h time-window centered on the IceCube event time. A search on an extended time window of +/- 1 day has also yielded no detection (46% visibility probability). This yields a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 15 GeV.cm^-2 over the energy range 3.3 TeV - 3.4 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 34 GeV.cm^-2 (450 GeV - 280 TeV) for an E^-2.5 spectrum. ANTARES is the largest neutrino detector installed in the Mediterranean Sea, and is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is below 0.5 degrees. In the range 1-100 TeV, ANTARES has the best sensitivity to this position in the sky. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21924 SUBJECT: IceCube-170922A: HAWC follow-up DATE: 17/09/25 01:55:22 GMT FROM: Israel Martinez at HAWC Israel Martinez (University of Maryland) and Ignacio Taboada (Georgia Tech) report on behalf of the HAWC collaboration (https://www.hawc-observatory.org/collaboration/): On 2017/09/22 20:54:30.43 UTC IceCube detected a track-like, very-high-energy event with a high probability of being of astrophysical origin, at RA=77.43d and Dec=5.72d J2000. The up-to-date values were reported in GCN circular 21916. Two analyses were performed: * Search for a steady source. This analysis was performed on archival data from November 2014 to June 2017. Assuming a spectral index of -2.5 we searched in a 1.3deg circle around the IceCube reported location.The maximum significance is 3.5 sigma at RA=76.29deg and Dec=5.04deg. We estimate the number of trials to be ~130. We set an upper limit 95% CL on gamma rays for this period of: E^2 dN/dE = 5.62e-15 (E/7TeV)^-0.5 TeV cm^-2 s^-1. * Search for a transient source. The event location was not in HAWC's FOV at the time of detection, so this analysis was performed using data corresponding to the two nearest transits (MJD 58018.35-59018.60 and 58019.35-59019.60). Using the same spectral index and search window, the maximum significance is 2.4 sigma at RA=76.45deg and Dec=5.58deg. We set an upper limit 95% CL on gamma rays for this period of: E^2 dN/dE = 2.26e-13 (E/7TeV)^-0.5 TeV cm^-2 s^-1. HAWC is a very-high-energy gamma-ray observatory located in Central Mexico at latitude 19 deg North. It operates 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: 21930 SUBJECT: IceCube-170922A: Swift-XRT observations DATE: 17/09/26 14:34:30 GMT FROM: Azadeh Keivani at PSU A. Keivani (PSU), P.A. Evans (U. Leicester), J.A. Kennea (PSU), D.B. Fox (PSU), D.F. Cowen (PSU), J.P. Osborne (U. Leicester), and F.E. Marshall (GSFC) report on behalf of the Swift-IceCube collaboration: Swift has observed the field of the IceCube EHE event, IceCube-170922A (revision 0, https://gcn.gsfc.nasa.gov/notices_amon/50579430_130033.amon), utilizing the on-board 19-point tiling pattern to cover a region centred on RA,Dec (J2000) = (77.2866d, +5.7537d), with a radius of approximately 0.8 degrees. Swift-XRT collected ~800 s per field of PC mode data per tile. The observations were taken between 00:09:16 UT and 22:42:08 UT on 2017 September 23 (i.e. from 11.7 ks to 92.9 ks after the neutrino trigger), and covered 2.1 square degrees. Nine X-ray sources are detected in the observations. Eight of these correspond to known X-ray emitters. One object (Source 6) is not catalogued in X-rays, however it lies 5.7" from PMN J0511+0538 which is a radio source. The X-ray source position is RA,Dec (J2000) = (77.8658d, +5.6420d) which is equivalent to: RA = 05h 11m 27.80s Dec = +05d 38' 31.2" with an uncertainty of 7.1" [90% confidence radius]. The mean XRT count rate is 6.9 (+3.7, -2.8) e-3 ct s^-1. More XRT follow-up observations have been requested. The 3-sigma upper limit on the count rate in the rest of the field is 0.0093 ct s^-1, which corresponds to a 0.3-10 keV flux of 3.8e-13 erg cm^-2 s^-1 for a typical AGN spectrum (NH=3e20 cm^-2, Gamma=1.7). Overlaps between the different tiles account for 0.5 square degrees: in these regions the 3-sigma upper limit is 0.0057 ct s^-1, corresponding to 2.3e-13 erg cm^-2 s^-1. Source 1: ============= RA: 76.7226 ( = 05h 06m 53.42s) J2000 Dec: +6.1154 ( = +06d 06' 55.4") J2000 Error: +4.3 (arcsec, radius, 90% confidence). Peak Rate: 5.6e-02 +/- 1.4e-02 ct/sec (0.3-10 keV) Peak Flux: 2.3e-12 +/- 5.7e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: 1RXS J050653.3+060648 in the ROSAT/RASSBSC catalogue Separation: 7.6" from the XRT source Cat Rate: 1.2e-01 +/- 2.0e-02 ct/sec Cat Flux: 1.8e-12 +/- 3.0e-13 erg cm^-2 s^-1 (0.3-10 keV) A SIMBAD object `TYC 110-755-1' is 3.6" away. Source 2: ============= RA: 77.3571 ( = 05h 09m 25.70s) J2000 Dec: +5.6924 ( = +05d 41' 32.6") J2000 Error: +4.2 (arcsec, radius, 90% confidence). Peak Rate: 9.3e-02 +/- 2.1e-02 ct/sec (0.3-10 keV) Peak Flux: 3.8e-12 +/- 8.6e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: 1SXPS J050925.9+054134 in the 1SXPS catalogue Separation: 4.7" from the XRT source Cat Rate: 3.9e-02 +/- 2.6e-03 ct/sec Cat Flux: 1.7e-12 +/- 1.1e-13 erg cm^-2 s^-1 (0.3-10 keV) A SIMBAD object `QSO J0509+0541' is 4.8" away. Source 3: ============= RA: 77.6614 ( = 05h 10m 38.74s) J2000 Dec: +5.9082 ( = +05d 54' 29.5") J2000 Error: +5.1 (arcsec, radius, 90% confidence). Peak Rate: 1.5e-02 +/- 4.1e-03 ct/sec (0.3-10 keV) Peak Flux: 6.2e-13 +/- 1.7e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: 1RXS J051038.6+055432 in the ROSAT/RASSBSC catalogue Separation: 3.8" from the XRT source Cat Rate: 5.9e-02 +/- 1.4e-02 ct/sec Cat Flux: 1.7e-12 +/- 4.0e-13 erg cm^-2 s^-1 (0.3-10 keV) A SIMBAD object `2MASS J05103912+0554261' is 6.7" away. Source 4: ============= RA: 77.1391 ( = 05h 08m 33.38s) J2000 Dec: +5.5188 ( = +05d 31' 07.7") J2000 Error: +5.5 (arcsec, radius, 90% confidence). Peak Rate: 1.7e-01 +/- 1.3e-01 ct/sec (0.3-10 keV) Peak Flux: 7.0e-12 +/- 5.3e-12 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: XMMSL2 J050833.1+053121 in the XMM-NEWTON/XMMSLEWCLN catalogue Separation: 13.5" from the XRT source Cat Rate: 6.9e-01 +/- 2.9e-01 ct/sec Cat Flux: 6.1e-12 +/- 2.6e-12 erg cm^-2 s^-1 (0.3-10 keV) Source 5: ============= RA: 77.4264 ( = 05h 09m 42.34s) J2000 Dec: +5.7826 ( = +05d 46' 57.4") J2000 Error: +5.3 (arcsec, radius, 90% confidence). Peak Rate: 1.7e-02 +/- 6.4e-03 ct/sec (0.3-10 keV) Peak Flux: 7.0e-13 +/- 2.6e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: 1SXPS J050942.4+054655 in the 1SXPS catalogue Separation: 2.0" from the XRT source Cat Rate: 7.2e-03 +/- 1.2e-03 ct/sec Cat Flux: 3.1e-13 +/- 5.2e-14 erg cm^-2 s^-1 (0.3-10 keV) A SIMBAD object `HD 33326' is 2.1" away. Source 7: ============= RA: 77.1531 ( = 05h 08m 36.74s) J2000 Dec: +5.2053 ( = +05d 12' 19.1") J2000 Error: +6.0 (arcsec, radius, 90% confidence). Peak Rate: 2.5e-02 +/- 7.0e-03 ct/sec (0.3-10 keV) Peak Flux: 1.0e-12 +/- 2.9e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: XMMSL2 J050836.8+051224 in the XMM-NEWTON/XMMSLEWCLN catalogue Separation: 4.7" from the XRT source Cat Rate: 9.5e-01 +/- 4.1e-01 ct/sec Cat Flux: 9.5e-12 +/- 4.1e-12 erg cm^-2 s^-1 (0.3-10 keV) A SIMBAD object `V* V1848 Ori' is 5.8" away. Source 8: ============= RA: 77.2410 ( = 05h 08m 57.84s) J2000 Dec: +6.4408 ( = +06d 26' 26.9") J2000 Error: +5.9 (arcsec, radius, 90% confidence). Peak Rate: 3.0e-02 +/- 8.1e-03 ct/sec (0.3-10 keV) Peak Flux: 1.2e-12 +/- 3.3e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: 1RXS J050857.4+062633 in the ROSAT/RASSBSC catalogue Separation: 9.3" from the XRT source Cat Rate: 1.2e-01 +/- 1.8e-02 ct/sec Cat Flux: 2.5e-12 +/- 3.9e-13 erg cm^-2 s^-1 (0.3-10 keV) A SIMBAD object `1RXS J050857.4+062633' is 7.9" away. Source 9: ============= RA: 77.4368 ( = 05h 09m 44.83s) J2000 Dec: +5.3639 ( = +05d 21' 50.0") J2000 Error: +5.7 (arcsec, radius, 90% confidence). Peak Rate: 1.4e-02 +/- 5.0e-03 ct/sec (0.3-10 keV) Peak Flux: 5.7e-13 +/- 2.0e-13 erg cm^-2 s^-1 (0.3-10 keV) Cat Source: 1RXS J050944.9+052219 in the ROSAT/RASSFSC catalogue Separation: 28.9" from the XRT source Cat Rate: 2.1e-02 +/- 9.5e-03 ct/sec Cat Flux: 2.3e-13 +/- 1.1e-13 erg cm^-2 s^-1 (0.3-10 keV) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21941 SUBJECT: Further Swift-XRT observations of IceCube 170922A DATE: 17/09/28 11:58:48 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) A. Keivani (PSU), J.A. Kennea (PSU), D.B. Fox (PSU), D.F. Cowen (PSU), J.P. Osborne (U. Leicester), and F.E. Marshall (GSFC) report on behalf of the Swift-IceCube collaboration: Fermi-LAT has reported a gamma-ray source (blazar), TXS 0506+056 (3FGL J0509.4+0541 / 3FHL J0509.4+0542) which is located inside the IceCube-170922A event error region (Kopper & Blaufuss, GCN Circ. 21916) and is flaring above 800 MeV (Tanaka et al., ATEL #10791). This source is also observed in our Swift-XRT follow-up of IceCube-170922A (Source 2, 1SXPS J050925.9+054134 in the 1SXPS catalogue), reported previously by Keivani et al. (GCN #21930) We conducted a further 5 ks observation of this Source with Swift, beginning at 2017 Sep 27 at 18:52 UT (4.95 d after the neutrino event). In these data the X-ray source has brightened since we the original observations. The current spectral photon index (gamma) is 2.50 [+0.23, -0.12], similar to the historical value in 1SXPS: gamma = 2.32 [+0.33, -0.29] (http://www.swift.ac.uk/1SXPS/1SXPS%20J050925.9%2B054134; Evans et al. 2014). In our initial observations following the neutrino trigger, gamma was marginally harder but with large uncertainty: 1.9 [+0.8, -0.7]. The hardness ratio light curve of the observations taken since the neutrino trigger also shows evidence for spectral softening between the two epochs, suggesting that the source is undergoing spectral evolution. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22281 SUBJECT: IceCube-170922A: Konus-Wind upper limits DATE: 17/12/25 10:42:07 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline, on behalf of the Konus-Wind team, report: Using Konus-Wind (KW) data, we have performed a search for a gamma-ray transient around the time of the cosmic neutrino candidate IceCube-170922A (2017-09-22 20:54:30.43 UT, hereafter T0; Kopper&Blaufuss, GCN 21916; https://gcn.gsfc.nasa.gov/notices_amon/50579430_130033.amon) No triggered KW event happened from ~1.7 days before and up to ~3.5 days after T0. The closest waiting-mode event was ~5.5 hours after T0. Using waiting-mode data within the interval T0 +/- 1000 s, we found no significant (> ~5 sigma) excess over the background in both KW detectors on temporal scales from 2.944 s to 100 s in the 80-1000 keV band. We estimate an upper limit (90% conf.) on the 10 keV – 10 MeV fluence to 1.0x10^-6 erg/cm^2 for a burst lasting less than 2.944 s and having a typical KW short GRB spectrum (an exponentially cut off power law with alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding limiting peak flux is 3.1x10^-7 erg/cm^2/s (10 keV - 10 MeV, 2.944 s scale). All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22942 SUBJECT: IceCube-170922A: First Optical observations of the Neutrino Trigger by MASTER Global Net and 25 IceCube alerts inspection. DATE: 18/07/12 16:51:56 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tiurina, A.Kuznetsov, V.Chazov, I. Gorbunov, D. Vlasenko, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov Lomonosov Moscow State University,SAI D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk MASTER-Tavrida robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Crimea was pointed to the IceCube-170922A (Kopper et al. GCN #21916; ) 27 sec after notice time and 73 sec after trigger time at 2017-09-22 20:55:43 UT. On our first (180s exposure) set we cleary detected TXS 0506+056 within ICECUBE error-box (ra=77.2833 dec=5.75139 r=0.25). The 5-sigma upper limit has been about 17.5 mag on single and 19.5 on coadd images. Since 2017-09-22 20:55:43 (i.e 73 sec after trigger) till 2017-09-18 we have ~ 300 observations provided by MASTER-Tavrida, MASTER-SAAO, MASTER-OAFA, MASTER-Kislovodsk and MASTER-Blagoveschensk. The object zenith distance was 84 degree at a time of first observations and it was rise. Unfortunately, we were extremely busy at this time handling the kiln on August 17, 2017, which we detected independent of the Chilean telescopes (Abbot et al 2017ApJ...848L..12A; Lipunov et al. 2017ApJ...850L...1L). Our telescopes react to 25 IceCube neutrino alerts ( 5874 images!), starting with the famous neutrino triplet in whose publication we participate and made a decisive contribution to the optical inspection (Aartsen et al 2017, A&A, Vol 607, A115, DOI: 10.1051/0004-6361/201730620) Just in case, we report that we have previous, synchronous and subsequent optical observations of the ICECube neutrino alert on June 2018. Just in case, we report that we have precursor and synchronous observations of the neutrino alert of June 2018 with QSO inside 2 sigma error box. The message may be cited.