English
Related papers

Related papers: Introduction to Unified Schemes

200 papers

Dust reprocesses the intrinsic radiation of active galactic nuclei (AGNs) to emerge at longer wavelengths. The observed mid-infrared (MIR) luminosity depends fundamentally on the luminosity of the central engine, but in detail it also…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 N. A. Levenson , J. T. Radomski , C. Packham , R. E. Mason , J. J. Schaefer , C. M. Telesco

The origin of obscuration in Active Galactic Nuclei (AGN) is still an open debate. In particular, it is unclear what drives the relative contributions to the line-of-sight column densities from galaxy-scale and torus-linked obscuration. The…

Relativistic jets are ubiquitous in astrophysical systems that contain compact objects. They transport large amounts of energy to large distances from the source, and their interaction with the ambient medium has a crucial effect on the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Omer Bromberg , Ehud Nakar , Tsvi Piran , Re'em Sari

The current paradigm for radio-quiet AGNs is reviewed, taking into account new results from recent large-scale surveys carried out from the ground and from space. Topics include structure of the central engine, AGN demography,…

Astrophysics · Physics 2007-05-23 Sylvain Veilleux

The cosmic ray source spectrum produced by AGN (Active Galactic Nucleus) jets is calculated. A distinctive feature of these calculations is the account for the jet distribution on kinetic energy. The expected cosmic ray spectrum at the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 V. S. Ptuskin , S. I. Rogovaya , V. N. Zirakashvili

Studying the average properties of active galactic nuclei (AGN) host stellar populations is an important step in understanding the role of AGN in galaxy evolution and the processes which trigger and fuel AGN activity. Here we calculate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Aden R. Draper , David R. Ballantyne

The origin of diffuse high-energy neutrinos from TeV to PeV energies detected by IceCube Observatory remains a mystery. In our previous work, we have shown that hadronuclear (p-p) interactions in AGN jets could be important and generate…

High Energy Astrophysical Phenomena · Physics 2024-07-08 Rui Xue , Ze-Rui Wang , Jagdish C. Joshi , Wei-Jian Li

We propose a unified classification for BL Lac objects (BLs), focusing on the synchrotron peak frequency of the spectral energy distribution. The unification scheme is based on the angle Theta that describes the orientation of the…

Astrophysics · Physics 2016-08-30 Markos Georganopoulos , Alan P. Marscher

Warm absorbers and related phenomena are one of the observable manifestations of outflows or winds from active galactic nuclei (AGN). Warm absorbers are common in low luminosity AGN, they have been extensively studied observationally, and…

High Energy Astrophysical Phenomena · Physics 2019-11-06 T. Kallman , A. Dorodnitsyn

The differences between Narrow Line Seyfert 1 galaxies (NLS1s) and Broad Line AGNs (BLAGNs) are not completely understood; it is thought that they may have different inclinations and/or physical characteristics. The FWHM(Hb)-luminosities…

Astrophysics of Galaxies · Physics 2021-10-14 Maša Lakićević , Jelena Kovačević-Dojčinović , Luka Č. Popović

Most Active Galactic Nuclei (AGN) are `obscured', i.e. the nucleus is hiding behind a screen of absorbing material. The advantage of having the nucleus obscured is to make easier the observations of those emission components which originate…

Astrophysics · Physics 2009-11-07 G. Matt

Unified schemes of active galactic nuclei (AGN) require an obscuring dusty torus around the central source, giving rise to Seyfert 1 line spectrum for pole-on viewing and Seyfert 2 characteristics in edge-on sources. Although the observed…

Astrophysics · Physics 2009-11-07 M. Nenkova , Z. Ivezic , M. Elitzur

High-energy neutrinos and photons are complementary messengers, probing violent astrophysical processes and structural evolution of the Universe. X-ray and neutrino observations jointly constrain conditions in active galactic nuclei (AGN)…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Idunn B. Jacobsen , Kinwah Wu , Alvina Y. L. On , Curtis J. Saxton

This talk discusses the unified X-ray/UV absorption models in AGN. I will first review the models and discuss how they offer an unique opportunity to probe the near nuclear environment of AGNs. Recently, however, the validity of these…

Astrophysics · Physics 2007-05-23 Smita Mathur

Most dusty winds are described by a set of similarity functions of a single independent variable that can be chosen as the overall optical depth at visual. The self-similarity implies general scaling relations among the system parameters,…

Astrophysics · Physics 2016-01-27 Moshe Elitzur , Zeljko Ivezic , Dejan Vinkovic

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

A brief overview of jets and their central drivers is presented, with a focus on accreting black hole systems. In particular, scaling relations that elucidate some basic properties of the engines are derived, and the implications for the…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Amir Levinson

Partial dust obscuration in active galactic nuclei (AGN) has been proposed as a potential explanation for some cases of AGN variability. The dust-gas mixture present in AGN tori is accelerated by radiation pressure, leading to the launching…

Astrophysics of Galaxies · Physics 2024-10-08 Nadine H. Soliman , Philip F. Hopkins

Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods. Optical reverberation mapping allowed us to constrain the spatial dimension of the…

High Energy Astrophysical Phenomena · Physics 2017-12-05 P. A. Rojas Lobos , R. W. Goosmann , F. Marin , D. Savić

Relativistic jets of plasma are a key ingredient of many types of Active Galactic Nuclei (AGN). Today we know that AGNs are powered by the accretion of inter stellar material into the gravitational field of a Super Massive Black Hole and…

High Energy Astrophysical Phenomena · Physics 2017-05-24 Giovanni La Mura , Giovanni Busetto , Stefano Ciroi , Piero Rafanelli , Marco Berton , Enrico Congiu , Valentina Cracco , Michele Frezzato