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pro vyhledávání: '"Dermer, Charles D."'
Autor:
Dermer, Charles D.
Knowledge of the distant high-energy universe comes from photons, ultra-high energy cosmic rays (UHECRs), high-energy neutrinos, and gravitational waves. The theory of high-energy messengers reviewed here focuses on the extragalactic background light
Externí odkaz:
http://arxiv.org/abs/1602.08722
Autor:
Dermer, Charles D.
This article reviews a few topics relevant to Galactic cosmic-ray astrophysics, focusing on the recent AMS-02 data release and Fermi Large Area Telescope data on the diffuse Galactic gamma-ray emissivity. Calculations are made of the diffuse cosmic-r
Externí odkaz:
http://arxiv.org/abs/1505.05757
Fermi-LAT analyses show that the gamma-ray photon spectral indices Gamma_gamma of a large sample of blazars correlate with the vFv peak synchrotron frequency v_s according to the relation Gamma_gamma = d - k log v_s. The same function, with different
Externí odkaz:
http://arxiv.org/abs/1504.03228
Publikováno v:
The Astrophysical Journal, 817 (2016) 59
Anisotropy in the arrival direction distribution of ultrahigh-energy cosmic rays (UHECRs) produced by powerful sources is numerically evaluated. We show that, taking account of the Galactic magnetic field, nondetection of significant anisotropy at $\
Externí odkaz:
http://arxiv.org/abs/1412.4716
The IceCube collaboration has reported neutrinos with energies between ~30 TeV and a few PeV that are significantly enhanced over the cosmic-ray induced atmospheric background. Viable high-energy neutrino sources must contain very high-energy and ult
Externí odkaz:
http://arxiv.org/abs/1406.2633
Publikováno v:
Phys.Rev.D 90 (2014) 023007
We study high-energy neutrino production in inner jets of radio-loud active galactic nuclei (AGN), taking into account effects of external photon fields and the blazar sequence. We show that the resulting diffuse neutrino intensity is dominated by qu
Externí odkaz:
http://arxiv.org/abs/1403.4089
Observations performed with the Fermi-LAT telescope have revealed the presence of a spectral break in the GeV spectrum of flat-spectrum radio quasars (FSRQs) and other low- and intermediate-synchrotron peaked blazars. We propose that this feature can
Externí odkaz:
http://arxiv.org/abs/1305.4159
Publikováno v:
Astrophys. J. Lett., 771 (2013) L32
Recent data from the \emph{Fermi} Large Area Telescope have revealed about a dozen distant hard-spectrum blazars that have very-high-energy (VHE; $\gtrsim 100$ GeV) photons associated with them, but most of them have not yet been detected by imaging
Externí odkaz:
http://arxiv.org/abs/1305.2138
Blazar spectral models generally have numerous unconstrained parameters, leading to ambiguous values for physical properties like Doppler factor delta or fluid magnetic field B'. To help remedy this problem, a few modifications of the standard lepton
Externí odkaz:
http://arxiv.org/abs/1304.6680
Autor:
Dermer, Charles D.
A shock-accelerated particle flux \propto p^-s, where p is the particle momentum, follows from simple theoretical considerations of cosmic-ray acceleration at nonrelativistic shocks followed by rigidity-dependent escape into the Galactic halo. A flux
Externí odkaz:
http://arxiv.org/abs/1206.2899