Results 141 to 150 of about 367,227 (284)

On black hole masses, radio-loudness and bulge luminosities of Seyfert galaxies [PDF]

open access: yes, 2001
We estimated black hole masses for 9 Seyfert 1 and 13 Seyfert 2 galaxies in the Palomar and CfA bright Seyfert samples using the tight correlation between black hole mass and bulge velocity dispersion. Combining other 13 Seyfert 1s and 2 Seyfert 2s in these samples but with black hole masses measured recently by reverberation mapping and stellar/gas ...
arxiv   +1 more source

Photometric Study of the Seyfert Galaxy NGC 4151

open access: yesOpen Astronomy, 2016
The results of CCD photometry in the Johnson-Morgan BV R system for the Seyfert galaxy NGC 4151 are reported. The observations were carried out from November 15, 2013 to May 13, 2016 with the 1-m telescope of Tien-Shan Astronomical Observatory of the ...
Shomshekova S. A.   +2 more
doaj   +1 more source

New Infrared Seyfert Galaxies [PDF]

open access: yesarXiv, 1998
We present optical spectra for new infrared Seyfert galaxies obtained with the 2.16m telescope at Beijing Astronomical Observatory (BAO). After wavelength and flux calibration, they are classified by the degree of nuclear activity: nine Seyfert 2 and three Seyfert 3 galaxies.
arxiv  

The Multitude of Unresolved Continuum Sources at 1.6 microns in Hubble Space Telescope images of Seyfert Galaxies [PDF]

open access: yes, 1999
We examine 112 Seyfert galaxies observed by the Hubble Space Telescope (HST) at 1.6 microns. We find that ~50% of the Seyfert 2.0 galaxies which are part of the Revised Shapeley-Ames (RSA) Catalog or the CfA redshift sample contain unresolved continuum sources at 1.6 microns. All but a couple of the Seyfert 1.0-1.9 galaxies display unresolved continuum
arxiv   +1 more source

Narrow Line Seyfert 1 Galaxies and the Evolution of Galaxies & Active Galaxies [PDF]

open access: yes, 2000
Narrow Line Seyfert 1 galaxies (NLS1s) are intriguing due to their continuum as well as emission line properties. The observed peculiar properties of the NLS1s are believed to be due to accretion rate close to Eddington limit. As a consequence, for a given luminosity, NLS1s have smaller black hole (BH) masses compared to normal Seyfert galaxies. Here
arxiv   +1 more source

Deep Chandra Observations of NGC 5728. III. Probing the High-resolution X-Ray Morphology and Multiphase Interstellar Medium Interactions in the Circumnuclear Region

open access: yesThe Astrophysical Journal
We present a detailed imaging analysis of 260 ks of subarcsecond resolution Chandra (ACIS-S) observations of the nearby Seyfert 2 galaxy NGC 5728. Our study focuses on the bright and diffuse soft X-ray emission within the galaxy's inner ∼1 kpc.
Anna Trindade Falcão   +4 more
doaj   +1 more source

Observations of a Magellanic Corona. [PDF]

open access: yesNature, 2022
Krishnarao D   +8 more
europepmc   +1 more source

The Host Galaxy Fluxes of Active Galaxy Nuclei Are Generally Overestimated by the Flux Variation Gradient Method

open access: yesUniverse
In terms of the variable nature of normal active galaxy nuclei (AGN) and luminous quasars, a so-called flux variation gradient (FVG) method has been widely utilized to estimate the underlying non-variable host galaxy fluxes.
Minxuan Cai   +4 more
doaj   +1 more source

Parsec-scale Nuclear Radio Structures in Seyfert Galaxies [PDF]

open access: yesarXiv, 2018
Radio outflows of extents ranging from a few parsecs to a few kiloparsecs are present in Seyfert and LINER galaxies that make up the `radio-quiet' AGN class. AGN jets and/or starburst superwinds have been suggested to produce these outflows. We present a brief review of radio outflows in Seyfert and LINER galaxies on different spatial scales. Very long
arxiv  

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