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133.
Decaying fermionic dark matter search with CALET
Saptashwa Bhattacharyya, 2017, original scientific article

Found in: ključnih besedah
Summary of found: ... cosmic rays detectors, dark matter detectors, dark matter...
Keywords: cosmic rays detectors, dark matter detectors, dark matter simulations
Published: 06.01.2021; Views: 1001; Downloads: 0
.pdf Fulltext (4,84 MB)

134.
CALET’s sensitivity to Dark Matter annihilation in the galactic halo
Saptashwa Bhattacharyya, Shoji Torii, Yoichi Asaoka, Holger Motzka, 2015, original scientific article

Found in: ključnih besedah
Summary of found: ...dark matter detectors, dark matter simulations, cosmic rays detectors...
Keywords: dark matter detectors, dark matter simulations, cosmic rays detectors
Published: 06.01.2021; Views: 983; Downloads: 0
.pdf Fulltext (3,44 MB)

135.
An interpretation of the cosmic ray e + + e − spectrum from 10 GeV to 3 TeV measured by CALET on the ISS
Saptashwa Bhattacharyya, 2019, original scientific article

Found in: ključnih besedah
Summary of found: ...CALET, cosmic rays, dark matter...
Keywords: CALET, cosmic rays, dark matter
Published: 06.01.2021; Views: 972; Downloads: 0
.pdf Fulltext (2,76 MB)

136.
Self consistent simulation of dark matter and background
Saptashwa Bhattacharyya, Holger Motz, Shoji Torii, Yoichi Asaoka, Yuko Okada, 2015, published scientific conference contribution

Found in: ključnih besedah
Keywords: dark matter, GALPROP, cosmic-rays
Published: 04.02.2021; Views: 916; Downloads: 0
.pdf Fulltext (527,13 KB)

137.
Measurement of the proton-air cross section with Telescope Array's Black Rock Mesa and Long Ridge fluorescence detectors, and surface array in hybrid mode
Mitsuhiro Abe, R. U. Abbasi, T. Abu-Zayyad, M. Allen, R. Azuma, E. Barcikowski, J. W. Belz, Jon Paul Lundquist, S. A. Blake, D. R. Bergman, 2020, original scientific article

Abstract: Ultra high energy cosmic rays provide the highest known energy source in the universe to measure proton cross sections. Though conditions for collecting such data are less controlled than an accelerator environment, current generation cosmic ray observatories have large enough exposures to collect significant statistics for a reliable measurement for energies above what can be attained in the lab. Cosmic ray measurements of cross section use atmospheric calorimetry to measure depth of air shower maximum (Xmax), which is related to the primary particle’s energy and mass. The tail of the Xmax distribution is assumed to be dominated by showers generated by protons, allowing measurement of the inelastic proton-air cross section. In this work the proton-air inelastic cross section measurement, σ_inel_p−air, using data observed by Telescope Array’s Black Rock Mesa and Long Ridge fluorescence detectors and surface detector array in hybrid mode is presented. σ_inel_p−air is observed to be 520.1 ± 35.8 [Stat.] +25.0 −40 [Sys.] mb at √s = 73 TeV. The total proton-proton cross section is subsequently inferred from Glauber formalism and is found to be σ_tot_pp = 139.4 +23.4−21.3[Stat.] +15.0−24.0[Sys.] mb.
Found in: ključnih besedah
Summary of found: ...Ultra high energy cosmic rays provide the highest known energy source...
Keywords: cosmic rays, astroparticles, proton-air cross section
Published: 04.02.2021; Views: 1074; Downloads: 0
.pdf Fulltext (1,99 MB)

138.
Evidence for a supergalactic structure of magnetic deflection multiplets of ultra-high-energy cosmic rays
R. U. Abbasi, T. Abu-Zayyad, Mitsuhiro Abe, M. Allen, R. Azuma, E. Barcikowski, J. W. Belz, D. R. Bergman, S. A. Blake, Jon Paul Lundquist, 2020, original scientific article

Abstract: Evidence for a large-scale supergalactic cosmic-ray multiplet (arrival directions correlated with energy) structure is reported for ultra-high-energy cosmic-ray (UHECR) energies above 1019 eV using 7 years of data from the Telescope Array (TA) surface detector and updated to 10 years. Previous energy–position correlation studies have made assumptions regarding magnetic field shapes and strength, and UHECR composition. Here the assumption tested is that, because the supergalactic plane is a fit to the average matter density of the local large-scale structure, UHECR sources and intervening extragalactic magnetic fields are correlated with this plane. This supergalactic deflection hypothesis is tested by the entire field-of-view (FOV) behavior of the strength of intermediate-scale energy–angle correlations. These multiplets are measured in spherical cap section bins (wedges) of the FOV to account for coherent and random magnetic fields. The structure found is consistent with supergalactic deflection, the previously published energy spectrum anisotropy results of the TA (the Hotspot and Coldspot), and toy-model simulations of a supergalactic magnetic sheet. The seven year data posttrial significance of this supergalactic structure of multiplets appearing by chance, on an isotropic sky, is found by Monte Carlo simulation to be 4.2σ. The 10 years of data posttrial significance is 4.1σ. Furthermore, the starburst galaxy M82 is shown to be a possible source of the TA Hotspot, and an estimate of the supergalactic magnetic field using UHECR measurements is presented.
Found in: ključnih besedah
Keywords: extragalactic magnetic fields, ultra-high-energy cosmic radiation, cosmic rays, high energy astrophysics, astrophysical magnetism, cosmic ray astronomy, cosmic ray sources
Published: 05.02.2021; Views: 1141; Downloads: 84
URL Fulltext (0,00 KB)
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139.
Search for large-scale anisotropy on arrival directions of ultra-high-energy cosmic rays observed with the telescope array experiment
Mitsuhiro Abe, R. U. Abbasi, T. Abu-Zayyad, M. Allen, R. Azuma, E. Barcikowski, J. W. Belz, D. R. Bergman, S. A. Blake, Jon Paul Lundquist, 2020, original scientific article

Abstract: Motivated by the detection of a significant dipole structure in the arrival directions of ultra-high-energy cosmic rays above 8 EeV reported by the Pierre Auger Observatory (Auger), we search for a large-scale anisotropy using data collected with the surface detector array of the Telescope Array Experiment (TA). With 11 yr of TA data, a dipole structure in a projection of the R.A. is fitted with an amplitude of 3.3% ± 1.9% and a phase of 131° ± 33°. The corresponding 99% confidence-level upper limit on the amplitude is 7.3%. At the current level of statistics, the fitted result is compatible with both an isotropic distribution and the dipole structure reported by Auger.
Found in: ključnih besedah
Keywords: cosmic rays, ultra-high-energy cosmic radiation, cosmic ray sources, cosmic ray showers, cosmic ray detectors, cosmic ray astronomy, extragalactic astronomy
Published: 05.02.2021; Views: 1069; Downloads: 0
.pdf Fulltext (548,15 KB)

140.
Scrutinizing FR 0 radio galaxies as ultra-high-energy cosmic ray source candidates
Anita Reimer, Lukas Merten, Margot Boughelilba, Paolo Da Vela, Serguei Vorobiov, Fabrizio Tavecchio, Giacomo Bonnoli, Jon Paul Lundquist, Chiara Righi, 2021, original scientific article

Abstract: Fanaroff-Riley (FR) 0 radio galaxies compose a new class of radio galaxies, which are usually weaker but much more numerous than the well-established class of FR 1 and FR 2 galaxies. The latter classes have been proposed as sources of the ultra-high-energy cosmic rays (UHECRs) with energies reaching up to eV. Based on this conjecture, the possibility of UHECR acceleration and survival in an FR 0 source environment is examined in this work. In doing so, an average spectral energy distribution (SED) based on data from the FR 0 catalog (FR0CAT) is compiled. The resulting photon fields are used as targets for UHECRs, which suffer from electromagnetic pair production, photo-disintegration, photo-meson production losses, and synchrotron radiation. Multiple mechanisms are discussed to assess the UHECR acceleration probability, including Fermi-I order and gradual shear accelerations, and particle escape from the source region. This work shows that in a hybrid scenario, combining Fermi and shear accelerations, FR 0 galaxies can contribute to the observed UHECR flux, as long as where shear acceleration starts to dominate over escape. Even in less optimistic scenarios, FR 0s can be expected to contribute to the cosmic-ray flux between the knee and the ankle. Our results are relatively robust with respect to the realized magnetic turbulence model and the speed of the accelerating shocks.
Found in: ključnih besedah
Summary of found: ...proposed as sources of the ultra-high-energy cosmic rays (UHECRs) with energies reaching up to ...
Keywords: acceleration of particles, nonthermal radiation mechanisms, jets, active galaxies, cosmic rays
Published: 05.02.2021; Views: 1202; Downloads: 0
.pdf Fulltext (4,15 MB)
This document has many files! More...

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