Results 41 to 50 of about 6,380 (236)
The Astronomical Journal, 1982 As part of an ongoing program of measuring galaxy redshifts at Mount Hopkins observatory, we have discovered several previously unknown bright Seyfert galaxies. Most of the objects are of Seyfert type 2, but several are type 1 objects where the broad permitted line region is easily visible only for the H..cap alpha.. line.
J. P. Huchra, W. F. Wyatt, M. Davis
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Star formation in southern Seyfert galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 1998 We have produced radio maps, using the Australia Telescope Compact Array, of the central regions of six southern type 2 Seyfert galaxies (NGC 1365, 4945, 6221, 6810, 7582 and Circinus) with circumnuclear star formation, to estimate the relative contribution of star formation activity compared to activity from the active galactic nucleus (AGN).
Forbes, Duncan A., Norris, R. P.
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Recoiling Black Holes: Electromagnetic Signatures, Candidates, and Astrophysical Implications
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Supermassive black holes (SMBHs) may not always reside right at the centers of their host galaxies. This is a prediction of numerical relativity simulations, which imply that the newly formed single SMBH, after binary coalescence in a galaxy merger, can receive kick velocities up to several 1000 km/s due to anisotropic emission of gravitational waves ...
S. Komossa, Francesca Civano
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Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers
Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto +9 more
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The Cosmic History of Black Hole Growth from Deep Multiwavelength Surveys
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Significant progress has been made in the last few years on understanding how supermassive black holes form and grow. In this paper, we begin by reviewing the spectral signatures of active galactic nuclei (AGN) ranging from radio to hard X‐ray wavelengths.
Ezequiel Treister +2 more
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Acta Polytechnica CTU Proceedings, 2014 Of the 271 sources in the 3rd EGRET catalogue, 131 were reported as unidentied, i.e. not associated with any particular class of point source in the sky.
Pieter J. Meintjes +3 more
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AGN Obscuration and the Unified Model
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Unification Models of Active Galactic Nuclei postulate that all the observed differences between type 1 and type 2 objects are due to orientation effects with respect to the line of sight to the observer. The key ingredient of these models is the obscuring medium, historically envisaged as a toroidal structure on a parsec scale.
Stefano Bianchi +3 more
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X-Ray Luminous Non-Seyfert Galaxies [PDF]
Symposium - International Astronomical Union, 1994 There are now well established classes of X-ray emitting galaxies, which exhibit characteristic ranges of luminosity, for example Green et al. (1992). The ROSAT all sky survey, has detected a relatively small number of galaxies whose overall properties do not appear consistent with any of these classes. We discuss whether these X-ray luminous galaxies (
M.J. Ward +3 more
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A Practical Guide to the Massive Black Hole Cosmic History
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 I review our current understanding of massive black hole (MBH) formation and evolution along the cosmic history. After a brief introductory overview of the relevance of MBHs in the hierarchical structure formation paradigm, I discuss the main viable channels for seed BH formation at high redshift and for their subsequent mass growth and spin evolution.
A. Sesana, Francesco Shankar
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Spitzer spectra of Seyfert galaxies
, 2009 to appear in the proceedings of "The Starburst-AGN Connection Conference", Shanghai, China, 27 Oct - 1 Nov 2008, ASP Conference ...
Spinoglio, Luigi +3 more
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