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Author (up) HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title Detailed Analysis of the TeV gamma-Ray Sources 3HWC J1928+178, 3HWC J1930+188, and the New Source HAWC J1932+192 Type Journal Article
Year 2023 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 942 Issue 2 Pages 96 - 18pp
Keywords
Abstract The latest High Altitude Water Cherenkov (HAWC) point-like source catalog up to 56 TeV reported the detection of two sources in the region of the Galactic plane at galactic longitude 52 degrees < l < 55 degrees, 3HWC J1930+188 and 3HWC J1928+178. The first one is associated with a known TeV source, the supernova remnant SNR G054.1+00.3. It was discovered by one of the currently operating Imaging Atmospheric Cherenkov Telescope (IACT), the Very Energetic Radiation Imaging Telescope Array System (VERITAS), detected by the High Energy Stereoscopic System (H.E.S.S), and identified as a composite SNR. However, the source 3HWC J1928+178, discovered by HAWC and coincident with the pulsar PSR J1928+1746, was not detected by any IACT despite their long exposure on the region, until a recent new analysis of H.E.S.S. data was able to confirm it. Moreover, no X-ray counterpart has been detected from this pulsar. We present a multicomponent fit of this region using the latest HAWC data. This reveals an additional new source, HAWC J1932+192, which is potentially associated with the pulsar PSR J1932+1916, whose gamma-ray emission could come from the acceleration of particles in its pulsar wind nebula. In the case of 3HWC J1928+178, several possible explanations are explored, in an attempt to unveil the origins of the very-high-energy gamma-ray emission.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM USA, Email: armelle.jardin-blicq@mpi-hd.mpg.de;
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:000942614000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5484
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Author (up) HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title HAWC Study of the Ultra-high-energy Spectrum of MGRO J1908+06 Type Journal Article
Year 2022 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 928 Issue 2 Pages 116 - 13pp
Keywords
Abstract We report TeV gamma-ray observations of the ultra-high-energy source MGRO J1908+06 using data from the High Altitude Water Cherenkov Observatory. This source is one of the highest-energy known gamma-ray sources, with emission extending past 200 TeV. Modeling suggests that the bulk of the TeV gamma-ray emission is leptonic in nature, driven by the energetic radio-faint pulsar PSR J1907+0602. Depending on what assumptions are included in the model, a hadronic component may also be allowed. Using the results of the modeling, we discuss implications for detection prospects by multi-messenger campaigns.
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 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000776453700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5187
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Author (up) HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title Long-term Spectra of the Blazars Mrk 421 and Mrk 501 at TeV Energies Seen by HAWC Type Journal Article
Year 2022 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 929 Issue 2 Pages 125 - 12pp
Keywords
Abstract The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory surveys the very high-energy sky in the 300 GeV to >100 TeV energy range. HAWC has detected two blazars above 11 sigma, Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501). The observations are comprised of data taken in the period between 2015 June and 2018 July, resulting in similar to 1038 days of exposure. In this work, we report the time-averaged spectral analyses for both sources, above 0.5 TeV. Taking into account the flux attenuation due to the extragalactic background light, the intrinsic spectrum of Mrk 421 is described by a power law with an exponential energy cutoff with index alpha = 2.26 +/- (0.12)(stat)((+0.17)(-0.2))(sys) and energy cutoff E-c = 5.1 +/- (1.6)(stat)((+1.4)(-2.5))(sys) TeV, while the intrinsic spectrum of Mrk 501 is better described by a simple power law with index alpha = 2.61 +/- (0.11)(stat)((+)(0.01)(-0.07))(sys). The maximum energies at which the Mrk 421 and Mrk 501 signals are detected are 9 and 12 TeV, respectively. This makes these some of the highest energy detections to date for spectra averaged over years-long timescales. Since the observation of gamma radiation from blazars provides information about the physical processes that take place in their relativistic jets, it is important to study the broadband spectral energy distributions (SEDs) of these objects. For this purpose, contemporaneous data in the gamma-ray band to the X-ray range, and literature data in the radio to UV range, were used to build time-averaged SEDs that were modeled within a synchrotron-self Compton leptonic scenario.
Address [Albert, A.; Durocher, M.; Harding, J. P.] Los Alamos Natl Lab, Phys Div, 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:000785694100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5209
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Author (up) HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title Probing the Extragalactic Mid-infrared Background with HAWC Type Journal Article
Year 2022 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 933 Issue 2 Pages 223 - 8pp
Keywords
Abstract The extragalactic background light (EBL) contains all the radiation emitted by nuclear and accretion processes in stars and compact objects since the epoch of recombination. Measuring the EBL density directly is challenging, especially in the near-to-far-infrared wave band, mainly due to the zodiacal light foreground. Instead, gamma-ray astronomy offers the possibility to indirectly set limits on the EBL by studying the effects of gamma-ray absorption in the very high energy (VHE: >100 GeV) spectra of distant blazars. The High Altitude Water Cherenkov Gamma Ray Observatory (HAWC) is one of the few instruments sensitive to gamma rays with energies above 10 TeV. This offers the opportunity to probe the EBL in the near/mid-IR region: lambda = 1-100 μm. In this study, we fit physically motivated emission models to Fermi-LAT gigaelectronvolt data to extrapolate the intrinsic teraelectronvolt spectra of blazars. We then simulate a large number of absorbed spectra for different randomly generated EBL model shapes and calculate Bayesian credible bands in the EBL intensity space by comparing and testing the agreement between the absorbed spectra and HAWC extragalactic observations of two blazars. The resulting bands are in agreement with current EBL lower and upper limits, showing a downward trend toward higher wavelength values lambda > 10 μm also observed in previous measurements.
Address [Albert, A.; Durocher, M.; Harding, J. P.; Malone, K.] Los Alamos Natl Lab, Phys Div, Los Alamos, NM USA, Email: mkf5479@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:000826698600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5295
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Author (up) HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title Constraints on the Very High Energy Gamma-Ray Emission from Short GRBs with HAWC Type Journal Article
Year 2022 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 936 Issue 2 Pages 126 - 14pp
Keywords
Abstract Many gamma-ray bursts (GRBs) have been observed from radio wavelengths, and a few at very high energies (VHEs, >100 GeV). The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is well suited to study transient phenomena at VHEs owing to its large field of view and duty cycle. These features allow for searches of VHE emission and can probe different model assumptions of duration and spectra. In this paper, we use data collected by HAWC between 2014 December and 2020 May to search for emission in the energy range from 80 to 800 GeV coming from a sample of 47 short GRBs that triggered the Fermi, Swift, and Konus satellites during this period. This analysis is optimized to search for delayed and extended VHE emission within the first 20 s of each burst. We find no evidence of VHE emission, either simultaneous or delayed, with respect to the prompt emission. Upper limits (90% confidence level) derived on the GRB fluence are used to constrain the synchrotron self-Compton forward-shock model. Constraints for the interstellar density as low as 10(-2) cm(-3) are obtained when assuming z = 0.3 for bursts with the highest keV fluences such as GRB 170206A and GRB 181222841. Such a low density makes observing VHE emission mainly from the fast-cooling regime challenging.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Zhou, H.] Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA, Email: nifraija@astro.unam.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:000852139800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5354
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