Results 131 to 140 of about 18,989 (273)

Cascading Constraints from Neutrino-emitting Blazars: The Case of TXS 0506+056 [PDF]

open access: yesAstrophysical Journal, 2018
We present a procedure to generally constrain the environments of neutrino-producing sites in photomeson production models of jetted active galactic nuclei (AGNs) where any origin of the dominant target photon field can be accommodated.
A. Reimer, M. Boettcher, S. Buson
semanticscholar   +1 more source

A blazar in the epoch of reionization

open access: yesNature Astronomy
Abstract Relativistic jets are thought to play a crucial role in the formation and evolution of massive galaxies and supermassive black holes. Blazars, which are quasars with jets aligned along our line of sight, provide insights into the jetted population and have been observed up to redshifts of z = 6.1.
Eduardo Bañados   +23 more
openaire   +4 more sources

Polarization swings in blazars [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2017
11 pages, 18 figures, 2 tables; accepted for publication by ...
E. V. Kravchenko, Maxim Lyutikov
openaire   +3 more sources

Gamma-ray quasi-periodicities of blazars. A cautious approach [PDF]

open access: yesMonthly notices of the Royal Astronomical Society, 2018
The availability of about a decade of uninterrupted sky monitoring by the Fermi satellite has made possible to study long-term quasi-periodicities for high-energy sources.
S. Covino, A. Sandrinelli, Aldo Treves
semanticscholar   +1 more source

Variability of Blazars and Blazar Models over 38 Years [PDF]

open access: yesGalaxies, 2016
Since 1978, when BL Lac objects and violently variable quasars were married to become “blazars”, physical interpretations of the phenomenon have evolved. Remarkably, though, the general picture of relativistic jets beaming their radiation in our direction, proposed that year by Blandford and Rees, remains intact.
openaire   +3 more sources

Suborbital Fermi/LAT Analysis of the Brightest Gamma-Ray Flare of Blazar 3C 454.3

open access: yesGalaxies, 2017
Recent detection of suborbital gamma-ray variability of Flat Spectrum Radio Quasar (FSRQ) 3C 279 by Fermi Large Area Telescope (LAT) is in severe conflict with established models of blazar emission.
Krzysztof Nalewajko
doaj   +1 more source

The “Blazar Sequence” in the TeV Band

open access: yesThe Astrophysical Journal, 2023
The “blazar sequence” has been proposed for more than 20 yr, yet its nature is still unclear. In this work, for the first time we expand this topic to the TeV band by using a sample of 58 TeV blazars, including 48 blazars in the quiescent state and 21 ...
Zhihao Ouyang   +9 more
doaj   +1 more source

Optical Outburst of the Blazar S4 0954+658 in Early 2015

open access: yesGalaxies, 2016
We analyze the behavior of the BL Lac object S4 0954+658 during an unprecedented bright optical flare in early 2015. The optical flare was accompanied by a powerful γ -ray flare and the detection of very-high-energy γ -ray emission.
Daria Morozova   +8 more
doaj   +1 more source

Relativistic flows in blazars [PDF]

open access: yesAIP Conference Proceedings, 2001
The radiation we observe from blazars is most likely the product of the transformation of bulk kinetic energy into random energy. This process must have a relatively small efficiency (e.g. 10%) if jets are to power the extended radio-structures. Recent results suggest that the average power reaching the extended radio regions and lobes is of the same ...
openaire   +3 more sources

Mining the Blazar Sky [PDF]

open access: yes, 2006
7 pages, 2 figures. To appear in the proceedings of the Workshop "Mining the Sky", Munich, August 2000, ESO Astrophysics Symposia, in press.
Paolo Giommi, Paolo Padovani
openaire   +3 more sources

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