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Author KM3NeT Collaboration (Aiello, S. et al); Alves Garre, S.; Calvo, D.; Carretero, V.; Colomer, M.; Corredoira, I; Gozzini, S.R.; Hernandez-Rey, J.J.; Khan Chowdhury, N.R.; Manczak, J.; Muñoz Perez, D.; Palacios Gonzalez, J.; Pieterse, C.; Real, D.; Salesa Greus, F.; Thakore, T.; Zornoza, J.D.; Zuñiga, J.
Title Architecture and performance of the KM3NeT front-end firmware Type Journal Article
Year 2021 Publication Journal of Astronomical Telescopes, Instruments and Systems Abbreviated Journal J. Astron. Telesc. Instrum. Syst.
Volume 7 Issue 1 Pages 016001 - 24pp
Keywords neutrino telescope; acquisition firmware; time to digital converters; KM3NeT
Abstract The KM3NeT infrastructure consists of two deep-sea neutrino telescopes being deployed in the Mediterranean Sea. The telescopes will detect extraterrestrial and atmospheric neutrinos by means of the incident photons induced by the passage of relativistic charged particles through the seawater as a consequence of a neutrino interaction. The telescopes are configured in a three-dimensional grid of digital optical modules, each hosting 31 photomultipliers. The photomultiplier signals produced by the incident Cherenkov photons are converted into digital information consisting of the integrated pulse duration and the time at which it surpasses a chosen threshold. The digitization is done by means of time to digital converters (TDCs) embedded in the field programmable gate array of the central logic board. Subsequently, a state machine formats the acquired data for its transmission to shore. We present the architecture and performance of the front-end firmware consisting of the TDCs and the state machine.
Address [Aiello, Sebastiano; Leonora, Emanuele; Longhitano, Fabio; Randazzo, Nunzio] Ist Nazl Fis Nucl, Sez Catania, Catania, Italy, Email: dacaldia@ific.uv.es;
Corporate Author Thesis
Publisher Spie-Soc Photo-Optical Instrumentation Engineers Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2329-4124 ISBN Medium
Area (up) Expedition Conference
Notes WOS:000636679100031 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4784
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Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title Evidence that Ultra-high-energy Gamma Rays Are a Universal Feature near Powerful Pulsars Type Journal Article
Year 2021 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 911 Issue 2 Pages L27 - 8pp
Keywords
Abstract The highest-energy known gamma-ray sources are all located within 0.degrees 5 of extremely powerful pulsars. This raises the question of whether ultra-high-energy (UHE; >56 TeV) gamma-ray emission is a universal feature expected near pulsars with a high spin-down power. Using four years of data from the High Altitude Water Cherenkov Gamma-Ray Observatory, we present a joint-likelihood analysis of 10 extremely powerful pulsars to search for subthreshold UHE gamma-ray emission correlated with these locations. We report a significant detection (>3 sigma), indicating that UHE gamma-ray emission is a generic feature of powerful pulsars. We discuss the emission mechanisms of the gamma rays and the implications of this result. The individual environment, such as the magnetic field and particle density in the surrounding area, appears to play a role in the amount of emission.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Malone, K.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM 87545 USA, Email: kmalone@lanl.gov
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 (up) Expedition Conference
Notes WOS:000642352500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4796
Permanent link to this record
 

 
Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title HAWC Search for High-mass Microquasars Type Journal Article
Year 2021 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 912 Issue 1 Pages L4 - 12pp
Keywords
Abstract Microquasars with high-mass companion stars are promising very high energy (VHE; 0.1-100 TeV) gamma-ray emitters, but their behaviors above 10 TeV are poorly known. Using the High Altitude Water Cerenkov (HAWC) observatory, we search for excess gamma-ray emission coincident with the positions of known high-mass microquasars (HMMQs). No significant emission is observed for LS 5039, Cyg X-1, Cyg X-3, and SS 433 with 1523 days of HAWC data. We set the most stringent limit above 10 TeV obtained to date on each individual source. Under the assumption that HMMQs produce gamma rays via a common mechanism, we have performed source-stacking searches, considering two different scenarios: (I) gamma-ray luminosity is a fraction epsilon ( gamma ) of the microquasar jet luminosity, and (II) VHE gamma rays are produced by relativistic electrons upscattering the radiation field of the companion star in a magnetic field B. We obtain epsilon ( gamma ) < 5.4 x 10(-6) for scenario I, which tightly constrains models that suggest observable high-energy neutrino emission by HMMQs. In the case of scenario II, the nondetection of VHE gamma rays yields a strong magnetic field, which challenges synchrotron radiation as the dominant mechanism of the microquasar emission between 10 keV and 10 MeV.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Malone, K.] Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA, Email: kefang@physics.wisc.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 (up) Expedition Conference
Notes WOS:000646368700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4798
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Author ANTARES Collaboration (Albert, A. et al); Alves, S.; Carretero, V.; Colomer, M.; Gozzini, R.; Hernandez-Rey, J J.; Khan-Chowdhury, N.R.; Manczak, J.; Pieterse, C.; Salesa Greus, F.; Thakore, T.; Zornoza, J.D.; Zuñiga, J.
Title Measurement of the atmospheric nu(e) and nu(mu) energy spectra with the ANTARES neutrino telescope Type Journal Article
Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 816 Issue Pages 136228 - 7pp
Keywords Neutrino telescope; Atmospheric neutrinos; ANTARES
Abstract This letter presents a combined measurement of the energy spectra of atmospheric nu(e) and nu(mu) in the energy range between similar to 100 GeV and similar to 50 TeV with the ANTARES neutrino telescope. The analysis uses 3012 days of detector livetime in the period 2007-2017, and selects 1016 neutrinos interacting in (or close to) the instrumented volume of the detector, yielding shower-like events (mainly from nu(e) + (nu) over bar (e) charged current plus all neutrino neutral current interactions) and starting track events (mainly from nu(mu) + (nu) over bar (mu) charged current interactions). The contamination by atmospheric muons in the final sample is suppressed at the level of a few per mill by different steps in the selection analysis, including a Boosted Decision Tree classifier. The distribution of reconstructed events is unfolded in terms of electron and muon neutrino fluxes. The derived energy spectra are compared with previous measurements that, above 100 GeV, are limited to experiments in polar ice and, for nu(mu), to Super-Kamiokande.
Address [Albert, A.; Drouhin, D.; Huang, F.; Organokov, M.; Pradier, T.] Univ Strasbourg, CNRS, IPHC, UMR 7178, F-67000 Strasbourg, France, Email: spurio@bo.infn.it;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area (up) Expedition Conference
Notes WOS:000647421500082 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4818
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Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title Probing the Sea of Cosmic Rays by Measuring Gamma-Ray Emission from Passive Giant Molecular Clouds with HAWC Type Journal Article
Year 2021 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 914 Issue 2 Pages 106 - 14pp
Keywords
Abstract The study of high-energy gamma rays from passive giant molecular clouds (GMCs) in our Galaxy is an indirect way to characterize and probe the paradigm of the “sea” of cosmic rays in distant parts of the Galaxy. By using data from the High Altitude Water Cerenkov (HAWC) Observatory, we measure the gamma-ray flux above 1 TeV of a set of these clouds to test the paradigm. We selected high galactic latitude clouds that are in HAWC's field of view and that are within 1 kpc distance from the Sun. We find no significant excess emission in the cloud regions, nor when we perform a stacked log-likelihood analysis of GMCs. Using a Bayesian approach, we calculate 95% credible interval upper limits of the gamma-ray flux and estimate limits on the cosmic-ray energy density of these regions. These are the first limits to constrain gamma-ray emission in the multi-TeV energy range (>1 TeV) using passive high galactic latitude GMCs. Assuming that the main gamma-ray production mechanism is due to proton-proton interaction, the upper limits are consistent with a cosmic-ray flux and energy density similar to that measured at Earth.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Malone, K.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM 87545 USA, Email: hgayala@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 (up) Expedition Conference
Notes WOS:000663912700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4858
Permanent link to this record