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Related papers: Issues in Blazar Research

200 papers

We report the variation of the spectral energy distribution (SED) of blazars as a function of source activity, based on available, simultaneous multi-wavelength (MWL) observations of BL Lac objects. We use a fully automatized \c{hi}2…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Nijil Mankuzhiyil , Stefano Ansoldi , Massimo Persic , Fabrizio Tavecchio

We summarize results presented at this conference with special emphasis on hard processes with jets and heavy quarks, soft particle production, small x structure functions and diffraction as well as heavy ion collisions and quark gluon…

High Energy Physics - Phenomenology · Physics 2007-05-23 Wolfgang Ochs

These lectures introduce some of the basic methods of perturbative QCD and their applications to phenomenology at high energy. Emphasis is given to techniques that are used to study QCD and related field theories to all orders in…

High Energy Physics - Phenomenology · Physics 2007-05-23 George Sterman

We have not identified for sure what is the mechanism launching, accelerating and collimating relativistic jets. The two most likely possibilities are the gravitational energy of the accreting matter or the rotational energy of a spinning…

High Energy Astrophysical Phenomena · Physics 2018-09-21 Gabriele Ghisellini

We present new Chandra and HST data for four gamma-ray blazars selected on the basis of radio morphology with the aim of revealing X-ray and optical emission from their jets at large scales. All the sources have been detected. Spectral…

Astrophysics · Physics 2011-02-11 F. Tavecchio , L. Maraschi , A. Wolter , C. C. Cheung , R. M. Sambruna , C. M. Urry

We introduce jet topics: a framework to identify underlying classes of jets from collider data. Because of a close mathematical relationship between distributions of observables in jets and emergent themes in sets of documents, we can apply…

High Energy Physics - Phenomenology · Physics 2018-06-20 Eric M. Metodiev , Jesse Thaler

We review the history of jets in high energy physics, and describe in more detail the developments of the past ten years, discussing new algorithms for jet finding and their main characteristics, and summarising the status of perturbative…

High Energy Physics - Phenomenology · Physics 2015-09-09 Matteo Cacciari

This paper reviews the topic of sub-parsec - scale jets in quasars, and covers the the following issues: observations of parsec and sub-parsec scale jets; energy dissipation and particle acceleration; radiative processes; magnetic fields,…

Astrophysics · Physics 2017-08-23 Marek Sikora , Greg Madejski

Blazar emission is dominated by non-thermal radiation from a relativistic jet pointing toward us, therefore undergoing Doppler beaming. This is responsible for flux enhancement and contraction of the variability time scales, so that most…

High Energy Astrophysical Phenomena · Physics 2019-08-13 C. M. Raiteri , M. Villata

We discuss the phenomenology of jet physics at hadron colliders, concentrating on the internal structure of jets, which is studied using the jet shape distribution or subjet distributions.

High Energy Physics - Phenomenology · Physics 2008-02-03 Michael H. Seymour

Active galactic nuclei come in many varieties. A minority of them are radio-loud, and exhibit two opposite prominent plasma jets extending from the proximity of the supermassive black hole up to megaparsec distances. When one of the…

High Energy Astrophysical Phenomena · Physics 2021-06-14 Claudia M. Raiteri , Massimo Villata

In this work, a time-dependent modeling is developed to study the emission properties of blazars in the low state. Motivated by various observations, we speculate and assume that numerous discrete radiation zones throughout the jet of a…

High Energy Astrophysical Phenomena · Physics 2023-09-22 Ruo-Yu Liu , Rui Xue , Ze-Rui Wang , Hong-Bin Tan , Markus Böttcher

I address the need for deep blazar surveys by showing that our current understanding of blazars is based on a relatively small number of intrinsically luminous sources. I then review the on-going deeper surveys, addressing in particular…

Astrophysics · Physics 2007-05-23 Paolo Padovani

We discuss recent progress and open questions in QCD jet physics, with particular emphasis on two areas: jet definitions and jet substructure.

High Energy Physics - Phenomenology · Physics 2007-05-23 M. H. Seymour

Machine learning (ML) and deep learning (DL) techniques are increasingly used across astrophysics, enabled by the growing availability of data and improved acquisition methods. These approaches now support tasks from redshift estimation to…

High Energy Astrophysical Phenomena · Physics 2025-07-09 E. Oukacha , Y. Becherini

The radiation observed by blazars is believed to originate from the transformation of bulk kinetic energy of relativistic jets into random energy. A simple way to achieve this is to have an intermittent central power source, producing…

Astrophysics · Physics 2007-05-23 Gabriele Ghisellini

The spectra of blazars form a sequence which can be parametrized in term of their observed bolometric luminosity. At the most powerful extreme of the sequence we find objects whose jet power can rival the power extracted by accretion, while…

Astrophysics · Physics 2007-05-23 G. Ghisellini

We estimate the power of relativistic, extragalactic jets by modelling the spectral energy distribution of a large number of blazars. We adopt a simple one-zone, homogeneous, leptonic synchrotron and inverse Compton model, taking into…

Astrophysics · Physics 2009-11-13 A. Celotti , G. Ghisellini

In this lecture I discuss jet-shape distributions and describe how from jet evolution one may design Monte Carlo simulations which are used in the analysis of short distance distributions in $\ee$-annihilation, lepton-hadron and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Giuseppe Marchesini

The rareness of blazars, combined with the previous history of relatively shallow, single-band surveys, has dramatically colored our perception of these objects. Despite a quarter-century of research, it is not at all clear whether current…