AGILE Detection of a Candidate Gamma-Ray Precursor to the ICECUBE-160731 Neutrino Event

Journal Article · Sun Sep 10 00:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA81C8· OSTI ID:22875827

Lucarelli, F.; Pittori, C.; Verrecchia, F.; Antonelli, L. A. ^[1]; Donnarumma, I. ^[2]; Tavani, M.; Pacciani, L.; Piano, G. ^[3]; Bulgarelli, A. ^[4]; Giuliani, A.; Caraveo, P.; Mereghetti, S. ^[5]; Cattaneo, P. W.; Rappoldi, A. ^[6]; Colafrancesco, S. ^[7]; Longo, F. ^[8]; Morselli, A. ^[9]; Pellizzoni, A.; Pilia, M.; others, and

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1. ASI Science Data Center (ASDC), Via del Politecnico snc, I-00133 Roma (Italy)
2. Agenzia Spaziale Italiana (ASI), Via del Politecnico snc, I-00133 Roma (Italy)
3. INAF/IAPS–Roma, Via del Fosso del Cavaliere 100, I—00133 Roma (Italy)
4. INAF/IASF—Bologna, Via Gobetti 101, I-40129 Bologna (Italy)
5. INAF/IASF–Milano, via E.Bassini 15, I-20133 Milano (Italy)
6. INFN—Pavia, Via Bassi 6, I-27100 Pavia (Italy)
7. INAF–OAR, via Frascati 33, I-00078 Monte Porzio Catone (Roma) (Italy)
8. Dip. di Fisica, Universita di Trieste and INFN, Via Valerio 2, I-34127 Trieste (Italy)
9. INFN—Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy)

On 2016 July 31 the ICECUBE collaboration reported the detection of a high-energy starting event induced by an astrophysical neutrino. Here, we report on a search for a gamma-ray counterpart to the ICECUBE-160731 event, made with the AGILE satellite. No detection was found spanning the time interval of ±1 ks around the neutrino event time T {sub 0} using the AGILE “burst search” system. Looking for a possible gamma-ray precursor in the results of the AGILE-GRID automatic Quick Look procedure over predefined 48-hr time bins, we found an excess above 100 MeV between 1 and 2 days before T {sub 0}, which is positionally consistent with the ICECUBE error circle, that has a post-trial significance of about 4σ. A refined data analysis of this excess confirms, a posteriori, the automatic detection. The new AGILE transient source, named AGL J1418+0008, thus stands as a possible ICECUBE-160731 gamma-ray precursor. No other space missions nor ground observatories have reported any detection of transient emission consistent with the ICECUBE event. We show that Fermi-LAT had a low exposure for the ICECUBE region during the AGILE gamma-ray transient. Based on an extensive search for cataloged sources within the error regions of ICECUBE-160731 and AGL J1418+0008, we find a possible common counterpart showing some of the key features associated with the high-energy peaked BL Lac (HBL) class of blazars. Further investigations on the nature of this source using dedicated SWIFT ToO data are presented.

• OSTI ID: 22875827
• Journal Information: Astrophysical Journal, Vol. 846, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
BL LACERTAE OBJECTS
CATALOGS
DATA ANALYSIS
DETECTION
EMISSION
GALAXIES
GAMMA RADIATION
MEV RANGE 100-1000
NEUTRINOS
PRECURSOR
SPACE