The effect of local galaxy density on the production of powerful radio sources by early-type galaxies

1985 ◽  
Vol 288 ◽  
pp. 122 ◽  
Author(s):  
T. M. Heckman ◽  
T. J. Carty ◽  
G. D. Bothun
Keyword(s):  
Radio Sources ◽  
Early Type ◽  
Powerful Radio

scholarly journals Properties of the Hot Ambient Medium of Early-type Galaxies Hosting Powerful Radio Sources

2020 ◽  
Vol 899 (2) ◽  
pp. 159
Author(s):  
Rachel L. S. Frisbie ◽  
Megan Donahue ◽  
G. Mark Voit ◽  
Thomas Connor ◽  
Yuan Li ◽  
...  
Keyword(s):  
Ambient Medium ◽  
Radio Sources ◽  
Early Type ◽  
Powerful Radio

A Radio Continuum Survey of Southern E and SO Galaxies at 2.7 GHz and 5.0 GHz

1982 ◽  
Vol 4 (4) ◽  
pp. 454-456
Author(s):  
E. M. Sadler
Keyword(s):  
Radio Emission ◽  
Radio Source ◽  
External Factor ◽  
Elliptical Galaxies ◽  
Radio Continuum ◽  
Radio Sources ◽  
Gravitational Perturbation ◽  
Early Type ◽  
Powerful Radio ◽  
Central Source

The reason why some early-type galaxies contain powerful radio sources is not yet well understood, but it is often suggested that an external factor such as interaction with a neighbouring galaxy may be involved in triggering a radio source (Gisler 1976, Dressel 1981, Hummel 1981b). Radio emission may be enhanced in galaxies which have a close companion for several reasons, such as a gravitational perturbation or the possibility of gas accreted from the companion fuelling a central source. The latter effect might be expected to be more pronounced in elliptical galaxies, which are generally gas-poor (Faber and Gallagher 1976).

scholarly journals Active Nuclei and Redshift Problems

1983 ◽  
Vol 6 ◽  
pp. 531-533
Author(s):  
Geoffrey Burbidge
Keyword(s):  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Radio Sources ◽  
Powerful Radio ◽  
Radiation Mechanism ◽  
X Ray ◽  
Major Interest ◽  
Relativistic Particles

More than 20 years ago V. A. Ambartsumian proposed that much of the activity in galaxies was dominated and even generated by their nuclei. Subsequent observational work in radio, optical and x-ray frequencies has borne out his prophecy, and major interest has centered about the nature of the machine in the galactic nucleus. The major characteristic of this machine is that it releases energy rapidly and often spasmodically by processes which are not thermonuclear in origin.The original studies which led to the conclusion that nuclei were all important were observations of the powerful radio sources and Seyfert galaxies, and evidence for the ejection of gas from galaxies of many types. The realization that the synchrotron mechanism was the dominant radiation mechanism and the later studies of Compton radiation were fundamental in leading to the conclusion that large fluxes of relativistic particles must be generated in galactic nuclei.

Supermassive Black Hole feedback in early type galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 119-125
Author(s):  
W. Forman ◽  
C. Jones ◽  
A. Bogdan ◽  
R. Kraft ◽  
E. Churazov ◽  
...  
Keyword(s):  
Dark Matter Halo ◽  
Scaling Relations ◽  
Radio Sources ◽  
Early Type ◽  
X Ray ◽  
Galaxy Groups ◽  
Sufficient Energy ◽  
The Galaxy ◽  
Simple Scaling ◽  
Halo Masses

AbstractOptically luminous early type galaxies host X-ray luminous, hot atmospheres. These hot atmospheres, which we refer to as coronae, undergo the same cooling and feedback processes as are commonly found in their more massive cousins, the gas rich atmospheres of galaxy groups and galaxy clusters. In particular, the hot coronae around galaxies radiatively cool and show cavities in X-ray images that are filled with relativistic plasma originating from jets powered by supermassive black holes (SMBH) at the galaxy centers. We discuss the SMBH feedback using an X-ray survey of early type galaxies carried out using Chandra X-ray Observatory observations. Early type galaxies with coronae very commonly have weak X-ray active nuclei and have associated radio sources. Based on the enthalpy of observed cavities in the coronae, there is sufficient energy to “balance” the observed radiative cooling. There are a very few remarkable examples of optically faint galaxies that are 1) unusually X-ray luminous, 2) have large dark matter halo masses, and 3) have large SMBHs (e.g., NGC4342 and NGC4291). These properties suggest that, in some galaxies, star formation may have been truncated at early times, breaking the simple scaling relations.

scholarly journals Magnetic Fields & Ionized Gas in Elliptical Galaxy Halos

1990 ◽  
Vol 140 ◽  
pp. 459-462
Author(s):  
Richard G. Strom
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Elliptical Galaxy ◽  
Radio Sources ◽  
Early Type ◽  
Ionized Gas ◽  
X Ray ◽  
Galaxy Halos ◽  
Field Strengths

Faraday depolarization estimates of thermal densities within the components of double radio sources agree well with estimates from X-ray observations of hot halos around early-type galaxies, provided magnetic field strengths are close to their equipartition values. Internal Faraday dispersion is the main cause of the depolarization observed.

scholarly journals Erratum: A sample of powerful radio sources for VLBI studies

1986 ◽  
Vol 222 (4) ◽  
pp. 895-895
Author(s):  
T. V. Cawthorne ◽  
P. A. G. Scheuer ◽  
I. Morison ◽  
T. W. B. Muxlow
Keyword(s):  
Radio Sources ◽  
Powerful Radio

Elliptical Galaxies—Getting to the Heart

1990 ◽  
Vol 8 (3) ◽  
pp. 238-242
Author(s):  
Elaine M. Sadler
Keyword(s):  
Optical Properties ◽  
Elliptical Galaxy ◽  
Elliptical Galaxies ◽  
Radio Sources ◽  
Powerful Radio

AbstractElliptical galaxies are at first sight a remarkably homogenous class of objects, yet some of them produce large and enormously powerful radio sources while others remain more or less quiescent. Why should this be so? What prompts the nucleus of an elliptical galaxy to become ‘active’? What, if anything, do elliptical galaxies have in common with the bulges of spirals? Here, I review some of the radio and optical properties of nearby elliptical galaxies, with special emphasis on events which take place within the central kiloparsec.

Correlated radio and optical asymmetries in powerful radio sources

1991 ◽  
Vol 371 ◽  
pp. 478 ◽  
Author(s):  
Patrick J. McCarthy ◽  
Wil van Breugel ◽  
Vijay K. Kapahi
Keyword(s):  
Radio Sources ◽  
Powerful Radio
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