scholarly journals Neutral hydrogen in elliptical galaxies with nuclear radio sources and optical emission lines

1982 ◽  
Vol 259 ◽  
pp. 55 ◽  
Author(s):  
L. L. Dressel ◽  
T. M. Bania ◽  
R. W. Oconnell
Keyword(s):  
Neutral Hydrogen ◽  
Optical Emission ◽  
Elliptical Galaxies ◽  
Emission Lines ◽  
Radio Sources

scholarly journals Compact Radio Sources in the Nuclei of Elliptical Galaxies

1972 ◽  
Vol 44 ◽  
pp. 222-223 ◽  
Author(s):  
R. D. Ekers
Keyword(s):  
Radio Emission ◽  
Angular Size ◽  
Optical Emission ◽  
Elliptical Galaxies ◽  
Emission Lines ◽  
Radio Sources ◽  
Radio Luminosity ◽  
Compact Source ◽  
Extended Radio

Ten percent of the intrinsically bright elliptical galaxies contain compact radio sources (angular size < 3 arc sec) with radio luminosity ∼ 1040 erg s−1. The presence of a compact source is correlated with the presence of extended radio emission and with the presence of optical emission lines.

scholarly journals Low-Luminosity Active Nuclei in Elliptical Galaxies

1987 ◽  
Vol 121 ◽  
pp. 443-450
Author(s):  
Elaine M. Sadler
Keyword(s):  
Optical Emission ◽  
Radio Galaxies ◽  
Elliptical Galaxies ◽  
Emission Lines ◽  
Gas Content ◽  
Radio Sources ◽  
Simple Relationship ◽  
Early Type ◽  
Optical Emission Spectrum ◽  
Radio Power

The results of a sensitive radio and optical survey of nearby early-type galaxies show that most (perhaps all) bright ellipticals have ‘active’ nuclei. These are characterized by a central non-thermal radio source and a weak LINER-like optical emission spectrum. There appears to be a smooth continuity in optical and radio properties from the weakest nearby sources to strong radio galaxies. Galaxies with radio sources usually show optical emission lines, but there is no simple relationship between gas content and radio power.

scholarly journals The Impact of the Early Stages of Radio Source Evolution on the ISM of the Host Galaxies

2003 ◽  
Vol 20 (1) ◽  
pp. 129-133 ◽  
Author(s):  
R. Morganti ◽  
C. N. Tadhunter ◽  
T. A. Oosterloo ◽  
J. Holt ◽  
A. Tzioumis ◽  
...  
Keyword(s):  
Radio Source ◽  
Radio Galaxy ◽  
Optical Emission ◽  
The Other ◽  
Emission Lines ◽  
Radio Sources ◽  
Host Galaxies ◽  
Cygnus A ◽  
Intermediate Size ◽  
The Impact

AbstractThe study of both neutral and ionised gas in young radio sources is providing key information on the effect the radio plasma has on the ISM of these objects. We present results obtained for the compact radio sources PKS 1549–79, 4C 12.50 and PKS 1814–63 and for the intermediate-size radio galaxy 3C 459. At least in the first two, low ionisation optical emission lines and HI absorption appear to be associated with the extended, but relatively quiescent, dusty cocoon surrounding the nucleus. The [OIII] lines are, on the other hand, mostly associated with the region of interaction between the radio plasma and the ISM, indicating a fast outflow from the centre. A case of fast outflow (up to ∼1000 km s-1) is also observed in HI in the radio source 4C 12.50. As the radio source evolves, any obscuring material along the radio axis is swept aside until, eventually, cavities (of the same kind as observed e.g. in Cygnus A) are hollowed out on either side of the nucleus. We may witness this phase in the evolution of a radio source in the radio galaxy 3C 459.

scholarly journals Extended Emission Lines in Radio Galaxies

1982 ◽  
Vol 97 ◽  
pp. 65-67
Author(s):  
R A E Fosbury
Keyword(s):  
Chemical Composition ◽  
Physical State ◽  
Radio Galaxy ◽  
Optical Emission ◽  
Radio Galaxies ◽  
Elliptical Galaxies ◽  
Emission Lines ◽  
Ionization Mechanism ◽  
Nuclear Activity ◽  
Extended Emission

In whatever physical state the gas is found, observations of the interstellar medium in elliptical galaxies are of considerable interest. This is particularly true in the case of radio galaxies where we believe that the gas is an indespensable part of the cause of nuclear activity and plays a role in the origin and the evolution of the radio galaxy phenomenon. In a few cases we are fortunate to find some of the gas to be ionized with a temperature of about 104 K where optical spectroscopy allows us to deduce something about the excitation/ionization mechanism, about its chemical composition and about its state of motion. Here I wish to summarize observations of three Southern radio galaxies which show optical emission lines from regions tens of kiloparsecs in extent.

The origin of the optical emission lines associated with extragalactic radio sources

1992 ◽  
Vol 384 ◽  
pp. 467 ◽  
Author(s):  
S. M. Viegas ◽  
E. M. de Gouveia dal Pino
Keyword(s):  
Optical Emission ◽  
Emission Lines ◽  
Radio Sources ◽  
Extragalactic Radio Sources

Excitation of the Optical Emission Lines in Quasi-Stellar Radio Sources

1966 ◽  
Vol 143 ◽  
pp. 268 ◽  
Author(s):  
Donald E. Osterbrock ◽  
Robert A. R. Parker
Keyword(s):  
Optical Emission ◽  
Emission Lines ◽  
Radio Sources

A Search for HI in Elliptical Galaxies with Nuclear Radio Sources

1982 ◽  
Vol 97 ◽  
pp. 309-310
Author(s):  
L. L. Dressel ◽  
T. M. Bania ◽  
R. W. O'Connell
Keyword(s):  
Neutral Hydrogen ◽  
Large Mass ◽  
Elliptical Galaxies ◽  
Continuum Emission ◽  
Radio Sources ◽  
Upper Limits ◽  
Continuum Radio ◽  
Arecibo Observatory ◽  
Radio Power ◽  
Made In

Many searches have been made in the last few years for 21 cm emission from neutral hydrogen in elliptical galaxies. Emission has been detected in several galaxies, which have 108 to 109 M⊙ of HI (for H○ = 100 km s−1Mpc−1). Upper limits between 106 and 109 M⊙ have been set for the HI mass in about 40 other galaxies. Why most E galaxies have so little gas, and why some few have detectable gas, remains a matter of great interest. Two of the galaxies with large HI mass, NGC 1052 and 4278, are known to have powerful nuclear continuum radio sources (P2380 ∼ 1022 WHz−1). Since both of these attributes are fairly rare among elliptical galaxies, their coexistence in these galaxies is not likely to have occurred by chance. We have therefore observed twelve other elliptical galaxies with nuclear radio power P2380 > 1022 WHz−1 at Arecibo Observatory, to determine whether a large mass of HI is a necessary auxillary to nuclear continuum emission.

scholarly journals The Nature of Faint Radio Sources

1986 ◽  
Vol 7 ◽  
pp. 345-353
Author(s):  
J V Wall ◽  
C R Benn ◽  
G Grueff ◽  
M Vigotti
Keyword(s):  
Elliptical Galaxies ◽  
Aperture Synthesis ◽  
Radio Sources ◽  
Mixed Group ◽  
Blue Galaxies ◽  
Infrared Data

AbstractRadio, optical and infrared data are combined to study the nature of mJy-sources found in the 5C12 aperture-synthesis survey. The optical counterparts are QSOs, giant elliptical galaxies of the 3CR type, and blue galaxies. We find that the blue galaxies are a mixed group; the suggestion of a new blue population of evolving spirals at mJy levels is not supported by our data.

scholarly journals Physical Properties of Nearby Dwarf Elliptical Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 69-69
Author(s):  
M. R. Seo ◽  
H. B. Ann
Keyword(s):  
Physical Properties ◽  
Stellar Populations ◽  
Elliptical Galaxies ◽  
High Density ◽  
Emission Lines ◽  
Dwarf Elliptical Galaxies ◽  
Nuclear Regions

AbstractMost dwarf elliptical galaxies except for ‘dE, N’ galaxies which are characterized by young stellar populations in the nuclear regions are located in the high density environment. The colors and spectra of ‘dE, N’ galaxies are different from other types, in the sense that they have redder colors with little emission lines. The majority of dwarf elliptical galaxies are younger than 7 Gyr with metallicity larger than [z/H]=−0.5.

Tables of physical and morphological properties of nearby extended radio galaxies

2021 ◽  
pp. 75-89
Author(s):  
R. R. Andreasyan ◽  
H. V. Abrahamyan
Keyword(s):  
Radio Galaxies ◽  
Elliptical Galaxies ◽  
Morphological Data ◽  
Morphological Properties ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Extended Radio

It is brought the physical and morphological data of 267 nearby radio galaxies identified with elliptical galaxies brighter than 18th magnitude (sample 1) and for 280 extragalactic radio sources with known position angles between the integrated intrinsic radio polarization and radio axes (sample 2).

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