Results 41 to 50 of about 16,452 (194)

Accretion discs in blazars [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2009
Accepted for publication (17 August 2009) in ...
Jolley, E. J. D.   +3 more
openaire   +3 more sources

The Spectral Energy Distribution of Fermi bright blazars [PDF]

open access: yes, 2009
(Abridged) We have conducted a detailed investigation of the broad-band spectral properties of the \gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS).
A. A. Abdo   +309 more
core   +4 more sources

Near infrared polarimetry of a sample of blazars*

open access: yesEPJ Web of Conferences, 2013
Polarization variability is one of the most ubiquitous characteristic of blazars. Near infrared (NIR)polarization measurements of blazars are not common, contrary to the optical ones.
Pulido J. A. Acosta   +8 more
doaj   +1 more source

BL Lac Contribution to the Extragalactic Gamma-Ray Background [PDF]

open access: yes, 2007
Very high energy gamma-rays from blazars traversing cosmological distances through the metagalactic radiation field can convert into electron-positron pairs in photon-photon collisions. The converted gamma-rays initiate electromagnetic cascades driven by
Aharonian   +37 more
core   +2 more sources

Discovery of Hidden Blazars [PDF]

open access: yesScience, 2001
Every radio-loud quasar may have blazar activities, according to a unified scheme where the differences in both optical and radio observations of radio-loud quasars are the result of different viewing angles. We have predicted that blazars may be detected using emission line ratio variations caused by variable illumination of gas clouds in the broad ...
Ma, Feng, Wills, Beverley J.
openaire   +3 more sources

General Physical Properties of Fermi Blazars

open access: yesThe Astrophysical Journal Supplement Series, 2023
We study the general physical properties of Fermi blazars using the Fermi fourth source catalog data (4FGL-DR2). The quasi-simultaneous multiwavelength data of Fermi blazars are fitted by using the one-zone leptonic model to obtain some physical ...
Yongyun Chen   +8 more
doaj   +1 more source

Gamma-Ray Observational Properties of TeV-Detected Blazars [PDF]

open access: yes, 2013
The synergy between the Fermi-LAT and ground-based Cherenkov telescope arrays gives us the opportunity for the first time to characterize the high-energy emission from blazars over 5 decades in energy, from 100 MeV to 10 TeV.
Boettcher, M.   +3 more
core   +3 more sources

Blazars in the early Universe [PDF]

open access: yes, 2011
We investigate the relative occurrence of radio--loud and radio-quiet quasars in the first billion years of the Universe, powered by black holes heavier than one billion solar masses. We consider the sample of high-redshfit blazars detected in the hard X-
Abdo   +48 more
core   +1 more source

The Parsec-Scale Jets of the TeV Blazars H 1426+428, 1ES 1959+650, and PKS 2155-304: 2001-2004 [PDF]

open access: yes, 2008
We present Very Long Baseline Array (VLBA) observations of the TeV blazars H 1426+428, 1ES 1959+650, and PKS 2155-304 obtained during the years 2001 through 2004.
B. Glenn Piner   +3 more
core   +3 more sources

Exploring the connection between radio and GeV-TeV gamma-ray emission in the 1FHL and 2FHL AGN samples [PDF]

open access: yes, 2017
The Fermi Large Area Telescope (LAT) revealed that blazars, representing the most extreme radio-loud active galactic nuclei (AGN) population, dominate the census of the gamma-ray sky, and a significant correlation was found between radio and gamma-ray ...
Costamante, L.   +6 more
core   +2 more sources

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