Results 211 to 220 of about 80,128 (249)
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2021
Almost all galaxies host in their center a supermassive black hole of mass between a million and tens of billions solar masses. Supermassive black holes grow in symbiosis with their host galaxies across the Hubble time, occasionally accreting surround matter, giving rise to an Active Galactic Nuclei (AGN).
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Almost all galaxies host in their center a supermassive black hole of mass between a million and tens of billions solar masses. Supermassive black holes grow in symbiosis with their host galaxies across the Hubble time, occasionally accreting surround matter, giving rise to an Active Galactic Nuclei (AGN).
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Reports on Progress in Physics, 1989
Recent observational and theoretical investigations of AGN are reviewed. The basic AGN characteristics (broad emission lines of abundant ions, X-ray emission, and a sharp starlike appearance) are summarized, and particular attention is given to the spectral classification of Seyfert galaxies, the AGN velocity fields and their measurement, low ...
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Recent observational and theoretical investigations of AGN are reviewed. The basic AGN characteristics (broad emission lines of abundant ions, X-ray emission, and a sharp starlike appearance) are summarized, and particular attention is given to the spectral classification of Seyfert galaxies, the AGN velocity fields and their measurement, low ...
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Astronomische Nachrichten, 2005
AbstractD01 Direct evidence of the receding ‘torus’ around active galactic nuclei of FRII radio galaxies and quasarsD02 Infrared emission from a clumpy and dusty torus around AGND03 Size and properties of AGN narrow–line regions from emission–line diagnosticsD04 Structural Variability of Intraday Variable SourcesD05 Stability of self‐gravitating ...
Martin Haas +6 more
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AbstractD01 Direct evidence of the receding ‘torus’ around active galactic nuclei of FRII radio galaxies and quasarsD02 Infrared emission from a clumpy and dusty torus around AGND03 Size and properties of AGN narrow–line regions from emission–line diagnosticsD04 Structural Variability of Intraday Variable SourcesD05 Stability of self‐gravitating ...
Martin Haas +6 more
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2014
So far, we have discussed the radio continuum (specifically: the synchrotron) emission of normal, i.e. star-forming galaxies, along with their magnetic field. As pointed out in Sect. 5.5, their synchrotron luminosity is closely associated with the star formation in their disks, this giving rise to the well-known radio-FIR correlation established for ...
Ulrich Klein, Andrew Fletcher
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So far, we have discussed the radio continuum (specifically: the synchrotron) emission of normal, i.e. star-forming galaxies, along with their magnetic field. As pointed out in Sect. 5.5, their synchrotron luminosity is closely associated with the star formation in their disks, this giving rise to the well-known radio-FIR correlation established for ...
Ulrich Klein, Andrew Fletcher
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1987
Well before the discovery of quasars, a special class of galaxies was known to harbor unusually powerful nuclei (Seyfert, 1943). Two primary defining characteristics of these active galactic nuclei (AGNs) are an intense point-like nuclear continuum source and strong, broad emission lines, neither of which could arise from ordinary stellar processes ...
Matthew A. Malkan +2 more
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Well before the discovery of quasars, a special class of galaxies was known to harbor unusually powerful nuclei (Seyfert, 1943). Two primary defining characteristics of these active galactic nuclei (AGNs) are an intense point-like nuclear continuum source and strong, broad emission lines, neither of which could arise from ordinary stellar processes ...
Matthew A. Malkan +2 more
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Physics Bulletin, 1980
C Hazard and S Mitton (eds) 1979 Cambridge: Cambridge University Press vii + 317 pp price £15 This book provides an extensive review of mainstream theoretical work on quasars and the nuclei of active galaxies. It is based on invited presentations to the Nato Cambridge conference of summer 1977.
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C Hazard and S Mitton (eds) 1979 Cambridge: Cambridge University Press vii + 317 pp price £15 This book provides an extensive review of mainstream theoretical work on quasars and the nuclei of active galaxies. It is based on invited presentations to the Nato Cambridge conference of summer 1977.
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2012
This AGN textbook gives an overview on the current knowledge of the Active Galactic Nuclei phenomenon. The spectral energy distribution will be discussed, pointing out what can be observed in different wavebands. The different physical models are presented together with formula important for the understanding of AGN physics.
Beckmann, Volker, Shrader, Chris R.
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This AGN textbook gives an overview on the current knowledge of the Active Galactic Nuclei phenomenon. The spectral energy distribution will be discussed, pointing out what can be observed in different wavebands. The different physical models are presented together with formula important for the understanding of AGN physics.
Beckmann, Volker, Shrader, Chris R.
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1990
The Swiss Society for Astrophysics and Astronomy organizes each year in the late winter or early spring an advanced course. The format of the school is always iden tical: three leading lecturers are invited to cover the subject in nine or ten lectures each and to deliver a written version of their lecture notes.
Blandford, R. D. +2 more
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The Swiss Society for Astrophysics and Astronomy organizes each year in the late winter or early spring an advanced course. The format of the school is always iden tical: three leading lecturers are invited to cover the subject in nine or ten lectures each and to deliver a written version of their lecture notes.
Blandford, R. D. +2 more
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Astrophysics and Space Science, 1995
The term Active Galactic Nuclei includes QSOs (Quasi-Stellar Objects), Seyfert galaxies, BL Lac objects and nuclei showing unusual amounts of star formation. South African work has centred on the photometric properties of these objects, both in the optical(UBVRI) and the infrared(JHKL). Photometry has been used to investigate the nature of the relevant
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The term Active Galactic Nuclei includes QSOs (Quasi-Stellar Objects), Seyfert galaxies, BL Lac objects and nuclei showing unusual amounts of star formation. South African work has centred on the photometric properties of these objects, both in the optical(UBVRI) and the infrared(JHKL). Photometry has been used to investigate the nature of the relevant
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Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources
Nature, 2021Zhen Cao, Felix Aharonian, Yiwei Bao
exaly