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Related papers: A pair plasma model for PKS 0208-512

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Using 190,000 spectra from the seventeenth data release of the Sloan Digital Sky Survey, we investigate the ultraviolet emission line properties in z=2 quasars. Specifically, we quantify how the shape of CIV 1549A and the equivalent width…

We present the results of observations of blazar PKS 1510-089 with the Herschel Space Observatory PACS and SPIRE instruments, together with multiwavelength data from Fermi/LAT, Swift, SMARTS and SMA. The source was found in a quiet state,…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Krzysztof Nalewajko , Marek Sikora , Greg M. Madejski , Katrina Exter , Anna Szostek , Ryszard Szczerba , Mark R. Kidger , Rosario Lorente

We study the stochastic variation of blazar emission under a 2-D spatially resolved leptonic jet model we previously developed. Random events of particle acceleration and injection in small zones within the emission region are assumed to be…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Xuhui Chen , Martin Pohl , Markus Böttcher , Shan Gao

The jet composition and energy dissipation mechanism of Gamma-ray bursts (GRBs) and Blazars are fundamental questions which remain not fully understood. One plausible model is to interpret the $\gamma$-ray emission of GRBs and optical…

High Energy Astrophysical Phenomena · Physics 2016-04-27 Wei Deng , Haocheng Zhang , Bing Zhang , Hui Li

This work proposes a methodology to test phenomenologically-motivated emission processes that account for the flux and polarization distribution and global structure of the 230 GHz sources imaged by the Event Horizon Telescope (EHT):…

X-ray emission from large scale extragalactic jets is likely to be due to inverse Compton scattering of relativistic particles off seed photons of both the cosmic microwave background field and the blazar nucleus. The first process…

Astrophysics · Physics 2009-10-31 A. Celotti , G. Ghisellini , M. Chiaberge

High-energy photons from dark matter annihilation contribute to the cosmic gamma-ray background (CGB). Since dark matter particles are weakly interacting, annihilation can happen only in high density regions such as dark matter halos. The…

Astrophysics · Physics 2007-05-23 Shin'ichiro Ando , Eiichiro Komatsu

We consider an extension of the Standard Model by a singlet scalar that accounts for the dark matter of the Universe. Within this model we compute the expected gamma ray flux from the annihilation of dark matter particles in a consistent…

High Energy Physics - Phenomenology · Physics 2009-03-27 Carlos E. Yaguna

PKS 1510-089 is one of the most variable blazars. Very high energy gamma ray emission from this source was observed by H.E.S.S. during March-April 2009 and by MAGIC from February 3 to April 3, 2012 quasi-simultaneously with multi-wavelength…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Partha Pratim Basumallick , Nayantara Gupta

Electron and positron fluxes in cosmic rays are currently measured with unprecedented precision by AMS-02 up to TeV energies, and represent unique probes for the local properties of our Galaxy. The interpretation of their spectra is at…

High Energy Astrophysical Phenomena · Physics 2022-09-13 Silvia Manconi

We present a novel determination of the astrophysical uncertainties associated to the secondary antiproton flux originating from cosmic-ray spallation on the interstellar gas. We select a set of propagation models compatible with the recent…

High Energy Astrophysical Phenomena · Physics 2016-02-04 Carmelo Evoli , Daniele Gaggero , Dario Grasso

Lately a specific kind of blazars drew the attention of the gamma-ray astronomy community: the extreme TeV BL Lacs, blazars that present an extremely energetic and hard emission at very high-energy. Explaining their features is still an…

High Energy Astrophysical Phenomena · Physics 2022-10-12 Alberto Sciaccaluga , Fabrizio Tavecchio

Taking into account spins, we classify all two-body non-relativistic Dark Matter annihilation channels to the allowed polarization states of Standard Model particles, computing the energy spectra of the stable final-state particles relevant…

High Energy Physics - Phenomenology · Physics 2013-10-07 Marco Cirelli , Mario Kadastik , Martti Raidal , Alessandro Strumia

We present the temporal and spectral study of blazar PKS 0208-512, using recent flaring activity from November 2019 to May 2020, as detected by the Fermi-LAT observatory. The contemporaneous X-ray, optical/UV observations from…

High Energy Astrophysical Phenomena · Physics 2022-07-12 Rukaiya Khatoon , Raj Prince , Zahir Shah , Sunder Sahayanathan , Rupjyoti Gogoi

We study the cosmic ray antiprotons with updated constraints on the propagation, proton injection, and solar modulation parameters based on the newest AMS-02 data near the Earth and Voyager data in the local interstellar space, and on the…

High Energy Astrophysical Phenomena · Physics 2018-06-15 Ming-Yang Cui , Xu Pan , Qiang Yuan , Yi-Zhong Fan , Hong-Shi Zong

The discovery of very-high-energy (VHE, E > 100 GeV) gamma-ray emission from intermediate- and low-frequency peaked blazars suggests that gamma-gamma absorption and pair cascading might occur in those objects. In previous papers, we…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Parisa Roustazadeh , Markus Boettcher

Because of their inherently high flux allowing the detection of clear signals, black hole X-ray binaries are interesting candidates for polarization studies, even if no polarization signals have been observed from them before. Such…

High Energy Astrophysical Phenomena · Physics 2015-05-27 P. Laurent , J. Rodriguez , J. Wilms , M. Cadolle Bel , K. Pottschmidt , V. Grinberg

We study the main spectral features of the gamma-ray fluxes observed by the High Energy Stereoscopic System (HESS) from the J1745-290 Galactic Center source during the years 2004, 2005 and 2006. In particular, we show that these data are…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 J. A. R. Cembranos , V. Gammaldi , A. L. Maroto

Missing cascades from TeV blazar beams indicate that collective plasma effects may play a significant role in their energy loss. It is possible to mimic the evolution of such highly energetic pair beams in laboratory experiments using…

High Energy Astrophysical Phenomena · Physics 2023-06-30 Marvin Beck , Oindrila Ghosh , Florian Grüner , Martin Pohl , Carl B. Schroeder , Günter Sigl , Ryan D. Stark , Benno Zeitler

Very high energy (VHE) gamma-rays undergo pair production with low energy photons of background radiation fields. This leads to an attenuation of the primary gamma-ray flux of extragalactic sources in the interaction with the extragalactic…

High Energy Astrophysical Phenomena · Physics 2014-10-08 Manuel Meyer , Dieter Horns