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Related papers: TeV Blazars and Cosmic Infrared Background Radiati…

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Over seventy blazars identified as sources of TeV gamma ray emission have been detected, including approximately sixty BL Lac objects and seven flat spectrum radio quasars. The distribution in space of these objects can be described by a…

High Energy Astrophysical Phenomena · Physics 2019-08-27 Aryeh Brill

The "blazar simplified view" is a new paradigm that explains well the diverse statistical properties of blazars observed over the entire electromagnetic spectrum on the basis of minimal assumptions on blazars' physical and geometrical…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Paolo Giommi , Paolo Padovani

A review of very high energy gamma-ray astronomy is presented. Particular attention is paid to the atmospheric Cherenkov imaging technique whose employment has resulted in detections of both galactic and extra-galactic objects at energies…

Astrophysics · Physics 2007-05-23 Stephen Fegan

Blazars are potential candidates of cosmic-ray acceleration up to ultrahigh energies ($E\gtrsim10^{18}$ eV). For an efficient cosmic-ray injection from blazars, $p\gamma$ collisions with the extragalactic background light (EBL) and cosmic…

High Energy Astrophysical Phenomena · Physics 2021-12-15 Saikat Das , Nayantara Gupta , Soebur Razzaque

A new method to constrain the distance of blazars with unknown redshift using combined observations in the GeV and TeV regimes will be presented. The underlying assumption is that the Very High Energy (VHE) spectrum corrected for the…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-02 Elisa Prandini , Giacomo Bonnoli , Laura Maraschi , Mose' Mariotti , Fabrizio Tavecchio

Gamma-rays propagating through space are likely to be extinguished via electron-positron pair production off of the ambient extragalactic background light (EBL). The spectrum of the EBL is produced by starlight (and starlight reprocessed by…

High Energy Astrophysical Phenomena · Physics 2013-12-11 Rebecca Reesman , T. P. Walker

We use the radio-infrared (IR) flux correlation bet ween star-forming galaxies in the local universe to derive a simple analytical expression between the intensity of the IR background and the brightness t emperature of the radio…

Astrophysics · Physics 2009-11-07 Eli Dwek , Michael K. Barker

Introduced in 1998 to attempt a first unified view of the broad-band emission properties of blazars, the blazar sequence has been extensively used in the past 25 years to guide observations as well as physical interpretation of the overall…

High Energy Astrophysical Phenomena · Physics 2022-02-16 Elisa Prandini , Gabriele Ghisellini

In this chapter, we discuss the contributions of gamma-ray astronomy at TeV energies to our understanding of the visible content and structure of the universe. We start from the present epoch with the second most intense electromagnetic…

High Energy Astrophysical Phenomena · Physics 2021-12-14 Elisa Pueschel , Jonathan Biteau

The light emitted by stars and accreting compact objects through the history of the Universe is encoded in the intensity of the extragalactic background light (EBL). Knowledge of the EBL is important to understand the nature of star…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-09 LAT Collaboration

With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes…

High Energy Astrophysical Phenomena · Physics 2013-02-25 Frank M. Rieger , Emma de Ona-Wilhelmi , Felix A. Aharonian

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…

High Energy Astrophysical Phenomena · Physics 2022-09-07 Mateo Fernandez Alonso

The most powerful persistent accelerators in the Universe are jetted active galaxies. Blazars, galaxies whose jets are directed towards Earth, dominate the extragalactic gamma-ray sky. Still, most of the highest-energy particle accelerators…

The observation of neutrinos from cosmic accelerators will be revolutionary. High energy neutrinos are closely connected to ultrahigh energy cosmic rays and their sources. Cosmic ray sources are likely to produce neutrinos and the…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Angela V. Olinto , Kumiko Kotera , Denis Allard

We derive a relation for the steepening of blazar gamma-ray spectra between the multi-GeV Fermi energy range and the TeV energy range observed by atmospheric Cerenkov telescopes. The change in spectral index is produced by two effects: (1)…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-12 Floyd W. Stecker , Sean T. Scully

The diffuse flux of cosmic neutrinos has been measured by the IceCube Observatory from TeV to PeV energies. We show that an improved characterization of this flux at the lower energies, TeV and sub-TeV, reveals important information on the…

High Energy Astrophysical Phenomena · Physics 2022-07-20 Ke Fang , John S. Gallagher , Francis Halzen

Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies $E\lesssim 1\,$TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of…

High Energy Astrophysical Phenomena · Physics 2016-08-11 Florian Schuppan , Christian Röken , Natalie Fedrau , Julia Becker Tjus

In this work, we use two different methods to determine the opacity of the TeV gamma-rays caused by the extragalactic background light (EBL) via e-e+ production due to photon-photon interaction. The first method, Model-Dependent Approach,…

High Energy Astrophysical Phenomena · Physics 2020-04-07 K. K. Singh , P. J. Meintjes

TeV blazars are known as prominent nonthermal emitters across the entire electromagnetic spectrum with their photon power peaking in the X-ray and TeV bands. If distant, absorption of gamma-ray photons by the extragalactic background light…

Astrophysics · Physics 2009-08-07 A. Reimer , L. Costamante , G. Madejski , O. Reimer , D. Dorner

The infrared properties of blazars can be studied from the statistical point of view with the help of sky surveys, like that provided by the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). However,…

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