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Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title A Survey of Active Galaxies at TeV Photon Energies with the HAWC Gamma-Ray Observatory Type Journal Article
Year 2021 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 907 Issue 2 Pages 67 - 18pp
Keywords Active galactic nuclei; Blazars; Gamma-rays; Gamma-ray sources; Sky surveys; Radio galaxies
Abstract The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory continuously detects TeV photons and particles within its large field of view, accumulating every day a deeper exposure of two-thirds of the sky. We analyzed 1523 days of HAWC live data acquired over four and a half years, in a follow-up analysis of 138 nearby (z < 0.3) active galactic nuclei from the Third Catalog of Hard Fermi-LAT sources culminating within 40 degrees of the zenith at Sierra Negra, the HAWC site. This search for persistent TeV emission used a maximum-likelihood analysis assuming intrinsic power-law spectra attenuated by pair production of gamma-ray photons with the extragalactic background light. HAWC clearly detects persistent emission from Mkn 421 and Mkn 501, the two brightest blazars in the TeV sky, at 65 sigma and 17 sigma level, respectively. Marginal evidence, just above the 3 sigma level, was found for three other known very high-energy emitters: the radio galaxy M87 and the BL Lac objects VER J0521+211 and 1ES 1215+303, the latter two at z similar to 0.1. We find a 4.2 sigma evidence for collective emission from the set of 30 previously reported very high-energy sources, with Mkn 421 and Mkn 501 excluded. Upper limits are presented for the sample under the power-law assumption and in the predefined (0.5-2.0), (2.0-8.0), and (8.0-32.0) TeV energy intervals.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Kunde, G. J.; Malone, K.] Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA, Email: alberto@inaoep.mx;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000612927500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4712
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Author ANTARES Collaboration (Albert, A. et al); Colomer, M.; Gozzini, R.; Hernandez-Rey, J.J.; Illuminati, G.; Khan-Chowdhury, N.R.; Manczak, J.; Thakore, T.; Zornoza, J.D.; Zuñiga, J.
Title Constraining the contribution of Gamma-Ray Bursts to the high-energy diffuse neutrino flux with 10 yr of ANTARES data Type Journal Article
Year 2021 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 500 Issue 4 Pages 5614-5628
Keywords acceleration of particles; neutrinos; transients: gamma-ray bursts; astroparticle physics
Abstract Addressing the origin of the astrophysical neutrino flux observed by IceCube is of paramount importance. Gamma-Ray Bursts (GRBs) are among the few astrophysical sources capable of achieving the required energy to contribute to such neutrino flux through p gamma interactions. In this work, ANTARFS data have been used to search for upward going muon neutrinos in spatial and temporal coincidence with 784 GRBs occurred from 2007 to 2017. For each GRB, the expected neutrino flux has been calculated in the framework of the internal shock model and the impact of the lack of knowledge on the majority of source redshifts and on other intrinsic parameters of the emission mechanism has been quantified. It is found that the model parameters that set the radial distance where shock collisions occur have the largest impact on neutrino flux expectations. In particular, the bulk Lorentz factor of the source ejecta and the minimum variability time-scale are found to contribute significantly to the GRB-neutrino flux uncertainty. For the selected sources, ANTARES data have been analysed by maximizing the discovery probability of the stacking sample through an extended maximum-likelihood strategy. Since no neutrino event passed the quality cuts set by the optimization procedure, 90 per cent confidence level upper limits (with their uncertainty) on the total expected diffuse neutrino flux have been derived, according to the model. The GRB contribution to the observed diffuse astrophysical neutrino flux around 100 TeV is constrained to be less than 10 percent.
Address [Albert, A.; Drouhin, D.; Huang, F.; Organokov, M.; Pradier, T.] Univ Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France, Email: silvia.celli@roma1.infn.it;
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000606297700092 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4677
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Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title 3HWC: The Third HAWC Catalog of Very-high-energy Gamma-Ray Sources Type Journal Article
Year 2020 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 905 Issue 1 Pages 76 - 14pp
Keywords Gamma-ray astronomy; Gamma-ray observatories; High energy astrophysics; Cosmic ray sources
Abstract We present a new catalog of TeV gamma-ray sources using 1523 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. The catalog represents the most sensitive survey of the northern gamma-ray sky at energies above several TeV, with three times the exposure compared to the previous HAWC catalog, 2HWC. We report 65 sources detected at >= 5 sigma significance, along with the positions and spectral fits for each source. The catalog contains eight sources that have no counterpart in the 2HWC catalog, but are within 1 degrees of previously detected TeV emitters, and 20 sources that are more than 1 degrees away from any previously detected TeV source. Of these 20 new sources, 14 have a potential counterpart in the fourth Fermi Large Area Telescope catalog of gamma-ray sources. We also explore potential associations of 3HWC sources with pulsars in the Australia Telescope National Facility (ATNF) pulsar catalog and supernova remnants in the Galactic supernova remnant catalog.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Malone, K.; Sinnis, G.; Ukwatta, T. N.] Los Alamos Natl Lab, Div Phys, Los Alamos, NM USA, Email: hfleisch@mtu.edu;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000599109900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4639
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Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title HAWC J2227+610 and Its Association with G106.3+2.7, a New Potential Galactic PeVatron Type Journal Article
Year 2020 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 896 Issue 2 Pages L29 - 9pp
Keywords Gamma-ray astronomy; Gamma-ray sources; Gamma-rays; Cosmic ray sources; Supernova remnants; Gamma-ray observatories
Abstract We present the detection of very-high-energy gamma-ray emission above 100 TeV from HAWC J2227+610 with the High-Altitude Water Cherenov Gamma-Ray Observatory (HAWC) observatory. Combining our observations with previously published results by the Very Energetic Radiation Imaging Telescope Array System (VERTIAS), we interpret the gamma-ray emission from HAWC J2227+610 as emission from protons with a lower limit in their cutoff energy of 800 TeV. The most likely source of the protons is the associated supernova remnant G106.3+2.7, making it a good candidate for a Galactic PeVatron. However, a purely leptonic origin of the observed emission cannot be excluded at this time.
Address [Albert, A.; Dingus, B. L.; Harding, J. P.; Malone, K.; Sinnis, G.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM 87545 USA, Email: hfleisch@mtu.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-8205 ISBN Medium
Area Expedition Conference
Notes WOS:000542724600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4445
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Author AMON and ANTARES Collaborations (Ayala Solares, H.A. et al); Barrios-Marti, J.; Coleiro, A.; Colomer, M.; Gozzini, R.; Hernandez-Rey, J.J.; Illuminati, G.; Khan-Chowdhury, N.R.; Lotze, M.; Thakore, T.; Zornoza, J.D.; Zuñiga, J.
Title A Search for Cosmic Neutrino and Gamma-Ray Emitting Transients in 7.3 yr of ANTARES and Fermi LAT Data Type Journal Article
Year 2019 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 886 Issue 2 Pages 98 - 8pp
Keywords BL Lacertae objects: general; cosmic rays; gamma-ray burst: general; gamma rays: general; neutrinos
Abstract We analyze 7.3 yr of ANTARES high-energy neutrino and Fermi Large Area Telescope (LAT) gamma-ray data in search of cosmic neutrino + gamma-ray (nu + gamma) transient sources or source populations. Our analysis has the potential to detect either individual nu + gamma transient sources (durations delta t less than or similar to 1000 s), if they exhibit sufficient gamma-ray or neutrino multiplicity, or a statistical excess of nu + gamma transients of individually lower multiplicities. Individual high gamma-ray multiplicity events could be produced, for example, by a single ANTARES neutrino in coincidence with a LAT-detected gamma-ray burst. Treating ANTARES track and cascade event types separately, we establish detection thresholds by Monte Carlo scrambling of the neutrino data, and determine our analysis sensitivity by signal injection against these scrambled data sets. We find our analysis is sensitive to nu + gamma transient populations responsible for >5% of the observed gamma-coincident neutrinos in the track data at 90% confidence. Applying our analysis to the unscrambled data reveals no individual nu + gamma events of high significance; two ANTARES track + Fermi gamma-ray events are identified that exceed a once per decade false alarm rate threshold (p = 17%). No evidence for subthreshold nu + gamma source populations is found among the track (p = 39%) or cascade (p = 60%) events. Exploring a possible correlation of high-energy neutrino directions with Fermi gamma-ray sky brightness identified in previous work yields no added support for this correlation. While TXS.0506+056, a blazar and variable (nontransient) Fermi gamma-ray source, has recently been identified as the first source of high-energy neutrinos, the challenges in reconciling observations of the Fermi gamma-ray sky, the IceCube high-energy cosmic neutrinos, and ultrahigh-energy cosmic rays using only blazars suggest a significant contribution by other source populations. Searches for transient sources of high-energy neutrinos thus remain interesting, with the potential for either neutrino clustering or multimessenger coincidence searches to lead to discovery of the first nu + gamma transients.
Address [Solares, H. A. Ayala; Cowen, D. F.; DeLaunay, J. J.; Keivani, A.; Mostafa, M.; Murase, K.; Turley, C. F.] Penn State Univ, Dept Phys, 104 Davey Lab, University Pk, PA 16802 USA, Email: cft114@psu.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000503245500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4227
Permanent link to this record