Results 61 to 70 of about 22,530 (230)
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
openaire +1 more source
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
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
openaire +3 more sources
Hidden starbursts in Seyfert 1 galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2003 5 pages, 1 figure.
Rodriguez-Ardila, A., Viegas, S.
openaire +2 more sources
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
The Astrophysical JournalWe analyze a sample of ~113,000 galaxies ( z
Huynh Anh N. Le, Yongquan Xue
doaj +1 more source
Extended Narrow-Line Region in Seyfert Galaxies
Frontiers in Astronomy and Space Sciences, 2017 We present our recent results about the extended narrow-line region (ENLR) of two nearby Seyfert 2 galaxies (IC 5063 and NGC 7212) obtained by modeling the observed line profiles and spectra with composite models (photoionization+shocks) in the different
Enrico Congiu +10 more
doaj +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
openaire +2 more sources
A Comparison of Star Formation Rates by Different Tracers in Nearby Galaxies
The Astrophysical Journal Supplement SeriesWe utilize a large sample of ∼113,000 galaxies ( z < 0.3) from the Sloan Digital Sky Survey with high-quality data to compare star formation rates (SFRs) across multiple diagnostic methods and examine their connection to the strength of active galactic ...
Huynh Anh N. Le +5 more
doaj +1 more source
Kinematic differences between NLS1 and BLAGN sources
, 2018 It is well-known that the higher policyclic aromatic hydrocarbon (PAH) abundance, lower black hole mass, higher accretion rate and lower luminosities are among the major characteristics of Narrow-Line Seyfert galaxies (NLS1), when they are compared to ...
Kovačević-Dojčinović, J. +2 more
core +1 more source