{
  "bibcode": "2020GCN.26915....1L",
  "body": "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n ANTARES 200127A: AMON + ANTARES Identification of a Low False-Alarm\nRate High-Energy Neutrino + Fermi LAT Coincidence\n\n\nC. F. Turley and D. B. Fox (for AMON https://www.amon.psu.edu/) +\nM. Ageron (CNRS/CPPM) A.Coleiro (Univ. de Paris/APC), D. Dornic\n(CNRS/CPPM), A. Kouchner (Univ. de Paris/APC ) (for ANTARES) report:\n\n\"During operations of the AMON ANTARES neutrino + Fermi LAT gamma-ray\nmultimessenger alerts, at 2020 January 27 at 18:52:02.9 UT, we identified\na low false alarm-rate (1 per 4.04 years) coincidence between a single\nANTARES neutrino and two Fermi LAT photons. An alert was automatically\ngenerated and, after human review, distributed to AMON partner\nfacilities at 2020 January 28, 02:09 UT. We are now reporting this\nalert publicly. Alert details are as follows:\n\n    Date:  27 January 2020\n    Time:  18:52:02.95 UT\n    R.A.:  16:01:47.1 (J2000)\n    Dec.: -52:57:28.6 (J2000)\n    r_90:  0.233 deg (90%-containment)\n    FAR:   0.25 yr-1\n\nANTARES 200127A is a high-energy neutrino-induced muon event detected\nby ANTARES (Ageron et al. 2011) with coordinates R.A. 16:16:33,\nDec. -53:36:46.8 (J2000) at 18:55:05 UT, and a p-value based on the\nnumber of hits used for the reconstruction of 0.433, which relates\nto the deposited energy.\n\nThe minimum false alarm rate coincidence from our analysis associates\nthis neutrino with two Fermi LAT photons. The first photon was detected at\n18:49:25.9 UT with coordinates R.A. 16:01:47.52, Dec. -52:57:19.44 (J2000)\nand energy 33.28 GeV. The second photon was detected at 18:51:37.9 UT with\ncoordinates R.A. 16:00:34.08, Dec -52:37:48.00 (J2000) and energy 2.18 GeV.\nThe best-fit localization and uncertainty for a point source yielding the\nANTARES 200127 neutrino and the photon is as quoted above. The false alarm\nrate for ANTARES neutrino + Fermi LAT gamma-ray coincidences of this quality\nor better is 1 per 4.036 years. We notice that this Fermi-LAT-ANTARES\ncoincidence is spatially matching the 50% credible region of the GW\nevent S200128d but preceded it by approximately 7.5 hours.\n\nDetails of the ANTARES + Fermi LAT coincidence search procedures are\nprovided in Ayala Solares et al. (AMON + ANTARES) 2019 (ApJ 886 (2019)\n98, ArXiv:1904.06420). False alarm rates are established from 73,000\nyears of simulated observation and take into account the point spread\nfunctions of the associated neutrino + photons, the known backgrounds\nat this sky position, the energy of the neutrino, and the energies of\nthe Fermi LAT photons (within broad ranges).\n\nThe AMON alert for this coincidence is provided in GCN Alert format\nbelow.\"\n\n//////////////////////////////////////////////////////////////////////\nTITLE: GCN/AMON NOTICE\nNOTICE_DATE: Mon 27 Jan 2020 18:52:02.95 UT\nNOTICE_TYPE: Fermi-LAT ANTARES coincidence\nAMON_NUM: 1441204786\nSRC_RA: 240.4463d {+16h 01m 47.1s} (J2000),\n240.8313d {+16h 03m 19.5s} (current),\n239.4871d {15:57:56.9} (1950)\nSRC_DEC: -52.9579d {-52d 57��� 29\"} (J2000),\n-53.0125d {-53d 00��� 45\"} (current),\n-52.8186d {-52d 49' 07\"} (1950)\n\nSRC_ERROR90: 0.233 [deg, stat, 90% containment]\nDISCOVERY_DATE: 18875 TJD;  27 DOY; 20/01/27 (yy/mm/dd)\nDISCOVERY_TIME: 67922 SOD {18:52:02.95} UT\nREVISION: 0\nDELTA_T: 339.09 [sec]\nSIGMA_T: 139.56 [sec]\nFAR: 0.2478 [yr^-1]\nSUN_POSTN: 309.754d {+20h 39m 01s} -18.431d {-18d 25��� 52\"}\nSUN_DIST: 62.98 [deg] Sun_angle= 4.20 [hr] (West of Sun)\nMOON_POSTN: 346.433d {+23h 05m 44s} -10.925d {-10d 55��� 31\"}\nMOON_DIST: 90.67 [deg]\nGAL_COORDS: 329.416, +0.233  [deg] galactic lon,lat of the event\nCOMMENTS: ALERT FROM FERMI-LAT ANTARES COINCIDENCE STREAM\n\n ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n\nColin F. Turley\n860-685-1260 Cell\ncft114@psu.edu email\n\nDepartment of Physics, Penn State University\n104 Davey Lab, Box 52\nUniversity Park, PA 16802-6300",
  "circularId": 26915,
  "createdOn": 1580216489000,
  "email": "cft114@psu.edu",
  "subject": "Fermi-LAT-ANTARES coincidence",
  "submitter": "Colin F Turley at AMON, Penn State U  <cft114@psu.edu>"
}