A Survey of the Seyfert Galaxies Based on Large-Scale Image-Tube Plates

Adams, Thomas F.

doi:10.1086/190416

Cited by 168 publications

(89 citation statements)

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“…Within this backdrop, Seyfert galaxies, which are generally considered to be the low-luminosity extension of the quasar phenomenon, traditionally have been regarded as radio-quiet objects. This perception perhaps has been reinforced further by the apparent correlation between radio loudness and host galaxy morphology, since most Seyfert nuclei reside in disk (spiral and lenticular) systems (e.g., Adams 1977 ;Yee 1983 ;MacKenty 1990 ;Ho, Filippenko, & Sargent 1997b). By virtue of their proximity, a high percentage of Seyfert galaxies are detectable as radio sources (e.g., de Bruyn & Wilson 1978 ;Ulvestad & Wilson 1984a, 1984b, 1989Edelson 1987 ;Rush, Malkan, & Edelson 1996 ;Ho & Ulvestad 2001).…”

Section: Introductionmentioning

confidence: 99%

Nuclear Luminosities and Radio Loudness of Seyfert Nuclei

Peng

2001

ApJ

220

265

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Historically, Seyfert nuclei have been considered to be radio-quiet active galactic nuclei (AGNs). We question this widely held assumption by showing that the distribution of the radio-to-optical luminosity ratio, when properly measured for the nuclear component, places the majority of R 4 L l (6 cm)/L l (B), type 1 Seyfert nuclei in the category of radio-loud AGNs, deÐned here as objects with R º 10. This result is further strengthened by strong correlations found between radio power and optical continuum and emission-line luminosities, as has been established previously for more powerful AGNs. We also present a new calibration of the relation between optical continuum and Balmer emission-line luminosities valid in the regime of low-luminosity AGNs.

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Section: Introductionmentioning

confidence: 99%

Nuclear Luminosities and Radio Loudness of Seyfert Nuclei

Peng

2001

ApJ

220

265

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“…The hosts of radio galaxies and Seyfert galaxies are different, and so the host properties of the radio-excess sources may enable us to distinguish between these possibilities. Classical Seyfert galaxies tend to occur in spirals (Adams 1977;MacKenty 1990). These are generally less luminous than the hosts of radio galaxies.…”

Section: Introductionmentioning

confidence: 99%

Radio-ExcessIRASGalaxies. II. Host Galaxies

2004

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This is the second of a series of papers studying a sample of radio-excess IRAS galaxies. These galaxies have radio emission in excess of that expected due to star formation, but largely fall between the traditional categories of radio-loud and radio-quiet active galaxies. R-band images of the hosts of far-infrared ( FIR)-luminous radioexcess galaxies are presented and analyzed. The hosts of the FIR-luminous radio-excess galaxies are luminous galaxies, on average 0.8 mag brighter than M Ã R . Their optical luminosities and morphologies are similar to comparison samples of radio-loud compact steep-spectrum and gigahertz peaked-spectrum sources and extended radio galaxies. We find a similar fraction of galaxies in our sample ($70%) with companions or distorted morphologies as in radio-loud comparison samples. This is consistent with radio activity being associated with tidal interaction. The majority (65%) of the FIR-luminous radio-excess galaxies have radio source sizes that are smaller than the optical host by more than an order of magnitude. These compact radio sources may be young precursors to classical radio galaxies or a different population of radio sources, possibly confined by the host interstellar medium. The host galaxy types were determined by analysis of the surface brightness distributions. The elliptical hosts have effective surface brightnesses and radii consistent with known ellipticals but inconsistent with a population of brightest cluster galaxies. Thus, it is unlikely these objects are the precursors of FR I radio galaxies. The disk hosts have smaller sizes and low radio excesses. However, they have a range of radio source sizes, which is not expected if they are radio-''loud'' Seyfert galaxies.

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“…also Adams 1977;Goad and Gallagher 1987;Pogge 1989;Kim 1989;Miyaji et al 1992;Mulchaey et al 1992) . In addition, circumnuclear emission was detected out to 25" ( ~4.4 kpc) from the nucleus.…”

Section: Recent Results On Ngc 3516mentioning

confidence: 99%

The line-emitting gas in active galaxies - A probe of the nuclear engine

Veilleux¹

1993

PASP

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ABSTRACT. This paper reviews some of the basic questions regarding the structure of the engine powering active galactic nuclei (AGN), the nature of the interaction between the AGN and the host galaxy, and the origin and evolution of AGN. The study of the dynamics and physical characteristics of the line-emitting gas in these objects has proven fruitful in addressing many of these issues. Recent advances in optical and infrared detector technology combined with the development of superior ground-based instruments have produced efficient new tools for the study of the line-emitting gas on nuclear (R % 1 pc) and galactic {R £ 50 pc) scales. Programs which take advantage of two of these new techniques, Fabry-Perot imaging spectroscopy and infrared spectroscopy, are described in this paper. The origin of nuclear activity in galaxies is also addressed in a third project which aims at determining the nature of luminous infrared galaxies.

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A Survey of the Seyfert Galaxies Based on Large-Scale Image-Tube Plates

Cited by 168 publications

References 0 publications

Nuclear Luminosities and Radio Loudness of Seyfert Nuclei

Nuclear Luminosities and Radio Loudness of Seyfert Nuclei

Radio-ExcessIRASGalaxies. II. Host Galaxies

The line-emitting gas in active galaxies - A probe of the nuclear engine

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