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Related papers: Tests of a Structure for Quasars

200 papers

In Unification Models, Active Galactic Nuclei (AGN) are believed to be surrounded by an axisymmetric structure of dust and gas, which greatly influences their observed properties according to the direction from which they are observed. The…

Astrophysics · Physics 2009-11-11 E. Ibar , P. Lira

Stars have been recognized as optimal laboratories to probe axion properties. In the last decades there have been significant advances in this field due to a better modelling of stellar systems and accurate observational data. In this work…

High Energy Physics - Phenomenology · Physics 2025-02-28 Pierluca Carenza , Maurizio Giannotti , Jordi Isern , Alessandro Mirizzi , Oscar Straniero

Clouds seem like an every-day experience. But -- do we know how clouds form on brown dwarfs and extra-solar planets? How do they look like? Can we see them? What are they composed of? Cloud formation is an old-fashioned but still…

Astrophysics · Physics 2014-11-17 Christiane Helling

Experimental results on hadronic structures are discussed in view of our physics understanding. Achievements and challenges are noted.

High Energy Physics - Experiment · Physics 2007-05-23 Martin Erdmann

(Abridged) Our deep multiwavelength campaign on NGC 5548 revealed an unusually strong X-ray obscuration. The resulting dramatic decrease in incident ionizing flux allowed us to construct a comprehensive physical, spatial and temporal…

If the jets of microquasars carry a significant power in the form of relativistic hadrons, then gamma rays and neutrinos can be produced by interactions with matter and photon fields either external or internal to the jet. In this paper I…

Astrophysics · Physics 2009-04-14 Gustavo E. Romero

We present results from our on-going MusE GAs FLOw and Wind (MEGAFLOW) survey, which consists of 22 quasar lines-of-sight, each observed with the integral field unit (IFU) MUSE and the UVES spectrograph at the ESO Very Large Telescopes…

We study high-pt jets from QCD and from highly-boosted massive particles such as tops, W, Z and Higgs, and argue that infrared-safe observables can help reduce QCD backgrounds. Jets from QCD are characterized by different patterns of energy…

High Energy Physics - Phenomenology · Physics 2014-11-18 Leandro G. Almeida , Seung J. Lee , Gilad Perez , George Sterman , Ilmo Sung , Joseph Virzi

Boosted resonances is a highly probable and enthusiastic scenario in any process probing the electroweak scale. Such objects when decaying into jets can easily blend with the cornucopia of jets from hard relative light QCD states. We review…

High Energy Physics - Phenomenology · Physics 2015-05-30 Leandro G. Almeida , Raz Alon , Michael Spannowsky

I present an overview of past, present and future research on microquasars and jets, showing that microquasars, i.e. galactic jet sources, are among the best laboratories for high energy phenomena and astroparticle physics. After reminding…

Astrophysics · Physics 2007-05-23 Sylvain Chaty

This paper is devoted to studying anisotropic compact stellar structures by adopting embedding class-1 technique in the background of modified Gauss-Bonnet gravity. The unknown constants are evaluated by the matching of interior spacetime…

General Relativity and Quantum Cosmology · Physics 2020-10-28 M. Sharif , Amna Ramzan

An integral part of the Unified Model for Active Galactic Nuclei (AGNs) is an axisymmetric obscuring medium, which is commonly depicted as a torus of gas and dust surrounding the central engine. However, a robust, dynamical model of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 S. K. Keating , J. E. Everett , S. C. Gallagher , R. P. Deo

Massive systems made of two or more stars are known to be the site for interesting physical processes -- including at least in some cases -- particle acceleration. Over the past decade, this topic motivated a particular effort to unveil the…

High Energy Astrophysical Phenomena · Physics 2015-06-16 M. De Becker , F. Raucq

Pulsar wind nebulae are fascinating systems, and archetypal sources for high-energy astrophysics in general. Due to their vicinity, brightness, to the fact that they shine at multi-wavelengths, and especially to their long-living emission…

High Energy Astrophysical Phenomena · Physics 2023-03-29 Barbara Olmi , Niccolò Bucciantini

Observational results from several experiments such as COBE, SP, Saskatoon, PYTHON, ARGO, MAX, MSAM, Tenerife and CAT are considered and a comparison is made with predictions from several models. Conclusions are reached about the viability…

Astrophysics · Physics 2007-05-23 Graca Rocha , Stephen Hancock

The study of neutron stars, or more general compact stars, is a topic of central interest in nuclear astrophysics. Furthermore, neutron stars serve as the only physical systems whose properties can be used to infer information on cold and…

Solar and Stellar Astrophysics · Physics 2013-07-19 S. Schramm , V. Dexheimer , R. Negreiros , T. Schürhoff , J. Steinheimer

We review the landscape of QCD axion models. Theoretical constructions that extend the window for the axion mass and couplings beyond conventional regions are highlighted and classified. Bounds from cosmology, astrophysics and experimental…

High Energy Physics - Phenomenology · Physics 2022-06-08 Luca Di Luzio , Maurizio Giannotti , Enrico Nardi , Luca Visinelli

We briefly describe the current version of the PHOENIX code. We then present some illustrative results from the modeling of Type Ia and Type II supernovae, hot stars, and irradiated giant planets. Good fits to observations can be obtained,…

I review here some of the main observational features in microquasars and AGNs as sources of high-energy gamma-rays as well as some of the current models that try to explain the emission in the gamma-ray domain.

Astrophysics · Physics 2007-05-23 J. M. Paredes

ISO provides a key new far-infrared window through which to observe the multi-wavelength spectral energy distributions (SEDs) of quasars and active galactic nuclei (AGN). It allows us, for the first time, to observe a substantial fraction…