Results 71 to 80 of about 186,144 (251)

The galactic cosmic ray ionization rate [PDF]

open access: yesProceedings of the National Academy of Sciences, 2006
The chemistry that occurs in the interstellar medium in response to cosmic ray ionization is summarized, and a review of the ionization rates that have been derived from measurements of molecular abundances is presented. The successful detection of large abundances of H 3 + in diffuse clouds and the ...
openaire   +2 more sources

Cosmic Rays from Gamma Ray Bursts in the Galaxy [PDF]

open access: yes, 2005
The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations of cosmic rays ...
Charles D. Dermer   +2 more
core   +3 more sources

The THESEUS Space Mission and the Infrared Telescope Calibration Unit

open access: yesAstronomische Nachrichten, EarlyView.
ABSTRACT The Transient High‐Energy Sky and Early Universe Surveyor (THESEUS) is an ESA M7 mission concept currently in Phase A, designed to exploit gamma‐ray bursts to probe the early Universe while advancing multi‐messenger and time‐domain astrophysics. To achieve its ambitious goals, THESEUS will combine wide‐band x‐ray and gamma‐ray monitors with an
András Péter Joó   +9 more
wiley   +1 more source

Cosmic Rays from Active Galactic Nuclei [PDF]

open access: yesThe Astrophysical Journal, 2008
Cosmic ray (CR) acceleration at the shock created by the expanding cocoons around active galactic nuclei (AGNs) is studied. It is shown that above the energy $10^{18}$ eV the overall energy spectrum of CRs, produced during the AGN evolution and released in the intergalactic space, has the form $N\propto ^{- }$, with $ \approx 2.6$, which extends up
openaire   +2 more sources

Theoretical challenges in acceleration and transport of ultra high energy cosmic rays: A review

open access: yesEPJ Web of Conferences, 2013
The wealth of data collected in the last few years thanks to the Pierre Auger Observatory and recently to the Telescope Array made the problem of the origin of ultra high energy cosmic rays a genuinely experimental/observational one.
Blasi Pasquale
doaj   +1 more source

Cosmic Ray Acceleration in Supernova Remnants

open access: yes, 2010
We review the main observational and theoretical facts about acceleration of Galactic cosmic rays in supernova remnants, discussing the arguments in favor and against a connection between cosmic rays and supernova remnants, the so-called supernova ...
Blasi, Pasquale
core   +1 more source

Grammage of cosmic rays around Galactic supernova remnants [PDF]

open access: yes, 2015
The residence time of cosmic rays (CRs) in the Galaxy is usually inferred from the measurement of the ratio of secondary-to-primary nuclei, for instance the boron (B)/carbon (C) ratio, which provides an estimate of the amount of matter traversed by CRs ...
M. D’Angelo, P. Blasi, E. Amato
semanticscholar   +1 more source

Feasibility Study for Application of Digitized Henize Mt. Wilson Michigan Southern Sky Hα$$ \boldsymbol{\alpha} $$ Survey Low‐Dispersive Spectral Plates for Searches for Anomalous and Highly Redshifted Objects

open access: yesAstronomische Nachrichten, EarlyView.
ABSTRACT The goal of this study is to confirm the feasibility of the use of digitized low dispersive MtWilson Michigan Southern Sky Hα$$ \alpha $$ survey astronomical photographic plates for modern astrophysical research. The detection of highly redshifted objects, such as early galaxies and quasars, is fundamental to understanding the universe's ...
Tauseef Ahmad Zafar   +3 more
wiley   +1 more source

Hidden No More: Spotlight on Tidal Disruption Events in Active Galactic Nuclei

open access: yesAstronomische Nachrichten, EarlyView.
ABSTRACT Tidal disruption events (TDEs) are typically discovered in previously quiescent galaxies. However, earlier studies have revealed a handful of TDEs occurring in pre‐existing active galactic nuclei (AGN). We discuss AT2019aalc, a promising TDE candidate in an AGN, and compare it to similar sources.
Patrik Milán Veres
wiley   +1 more source

Searches for Neutrinos from Large High Altitude Air Shower Observatory Ultra-high-energy γ-Ray Sources Using the IceCube Neutrino Observatory

open access: yesThe Astrophysical Journal Letters, 2023
Galactic PeV cosmic-ray accelerators (PeVatrons) are Galactic sources theorized to accelerate cosmic rays up to PeV in energy. The accelerated cosmic rays are expected to interact hadronically with nearby ambient gas or the interstellar medium, resulting
R. Abbasi   +389 more
doaj   +1 more source

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