Results 41 to 50 of about 160 (135)
Classifying Seyfert Galaxies with Deep Learning [PDF]
The Astrophysical Journal Supplement Series, 2021 Abstract The traditional classification for a subclass of the Seyfert galaxies is visual inspection or using a quantity defined as a flux ratio between the Balmer line and forbidden line. One algorithm of deep learning is the convolution neural network (CNN), which has shown successful classification results.
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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
wiley +1 more source
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, Norris, R. P.
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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
wiley +1 more source
Compact radio cores in Seyfert galaxies [PDF]
The Astrophysical Journal, 1994 We have observed a sample of 157 Seyfert galaxies with a 275 km baseline radio interferometer to search for compact, high brightness temperature radio emission from the active nucleus. We obtain the surprising result that compact radio cores are much more common in Seyfert 2 than in Seyfert 1 galaxies, which at first seems to be inconsistent with ...
Roy, A. L. +4 more
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Hidden starbursts in Seyfert 1 galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2003 5 pages, 1 figure.
Rodriguez-Ardila, A., Viegas, S.
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Markarian and Seyfert Galaxies [PDF]
Symposium - International Astronomical Union, 1999 Since this symposium is devoted to the 90th anniversary of Prof. Ambartsumian's birthday I would like to touch briefly upon some historical aspects of V. Ambartsumian's ideas on activity of nuclei of galaxies.
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HNC, HCN and CN in Seyfert galaxies [PDF]
Astronomy & Astrophysics, 2007 Accepted for publication in A&A. A selection of this paper will be presented as a poster in the FIR workshop 2007, held at Bad Honnef, Germany. High resolution figures in original paper.
Perez-Beaupuits, J. P. +2 more
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Symposium - International Astronomical Union, 1989 We present data for Seyfert and normal galaxies in the Revised Shapley-Ames Catalog. The type 2 Seyferts are stronger CO and Far-IR emitters (by factors of 2–4) than either normal galaxies or type 1 Seyferts. The Seyfert CO line-widths correlate with both the 21cm HI and [OIII]5007 line-widths.
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Effects of the environment on the properties of Seyfert galaxies [PDF]
Proceedings of the International Astronomical Union, 2004 We identify 175 Seyfert galaxies from the Southern Sky Redshift Survey - SSRS2. We use the entire SSRS2 catalog to investigate the correlation between the presence of AGN with host environment. The AGN phenomenon is more strongly correlated with the internal host properties, than with the external environment.
Maia, Marcio A. G. +3 more
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