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Author Guadilla, V. et al; Tain, J.L.; Algora, A.; Agramunt, J.; Gelletly, W.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S.E.A.; Rubio, B.; Valencia, E.
Title Characterization and performance of the DTAS detector Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 910 Issue Pages 79-89
Keywords beta decay; Total absorption gamma-ray spectrometer; Exotic nuclei; NaI(Tl) detector; Non-proportional scintillation light yield; Monte Carlo simulations
Abstract DTAS is a segmented total absorption y-ray spectrometer developed for the DESPEC experiment at FAIR. It is composed of up to eighteen NaI(Tl) crystals. In this work we study the performance of this detector with laboratory sources and also under real experimental conditions. We present a procedure to reconstruct offline the sum of the energy deposited in all the crystals of the spectrometer, which is complicated by the effect of NaI(Tl) light-yield non-proportionality. The use of a system to correct for time variations of the gain in individual detector modules, based on a light pulse generator, is demonstrated. We describe also an event-based method to evaluate the summing-pileup electronic distortion in segmented spectrometers. All of this allows a careful characterization of the detector with Monte Carlo simulations that is needed to calculate the response function for the analysis of total absorption gamma-ray spectroscopy data. Special attention was paid to the interaction of neutrons with the spectrometer, since they are a source of contamination in studies of beta-delayed neutron emitting nuclei.
Address [Guadilla, V; Tain, J. L.; Algora, A.; Agramunt, J.; Gelletly, W.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S. E. A.; Rubio, B.; Valencia, E.] CSIC Univ Valencia, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: guadilla@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000453652500010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3847
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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 and Fermi-LAT Detection of Extended Emission from the Unidentified Source 2HWC J2006+341 Type Journal Article
Year 2020 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 903 Issue 1 Pages L14 - 6pp
Keywords Gamma-rays; Interstellar medium
Abstract The discovery of the TeV point source 2HWC J2006+341 was reported in the second HAWC gamma-ray catalog. We present a follow-up study of this source here. The TeV emission is best described by an extended source with a soft spectrum. At GeV energies, an extended source is significantly detected in Fermi-LAT data. The matching locations, sizes, and spectra suggest that both gamma-ray detections correspond to the same source. Different scenarios for the origin of the emission are considered and we rule out an association to the pulsar PSR J2004+3429 due to extreme energetics required, if located at a distance of 10.8 kpc.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Malone, K.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM USA, Email: miguel.araya@ucr.ac.cr
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:000584890800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4591
Permanent link to this record
 

 
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
Permanent link to this record
 

 
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
Permanent link to this record