scholarly journals Comparison of Radio and Optical Polarization in Extended Extragalactic Radio Sources: II. Implications for the Magnetic Fields

1990 ◽  
Vol 140 ◽  
pp. 451-452
Author(s):  
K. Meisenheimer ◽  
H.-J. Röser
Keyword(s):  
Magnetic Fields ◽  
Radio Sources ◽  
Synchrotron Emission ◽  
Optical Polarization ◽  
Optical Studies ◽  
Extragalactic Source ◽  
Extragalactic Radio Sources ◽  
Extended Radio ◽  
Synchrotron Light

Although optical synchrotron light from an extragalactic source - the jet in M 87 - has been discovered more than 30 years ago (Baade 1956) there are still only a handful extended radio sources with established optical synchrotron emission (see Röser 1989 and references therein, also Meisenheimer et al. 1989b). We outline the relevance of optical studies and summarize some results concerning the magnetic fields in extragalactic radio sources.

scholarly journals Comparison of Radio and Optical Polarization in Extended Extragalactic Radio Sources: I. Observations

1990 ◽  
Vol 140 ◽  
pp. 449-450
Author(s):  
H.-J. Röser ◽  
K. Meisenheimer
Keyword(s):  
Spectral Index ◽  
Hot Spots ◽  
Near Infrared ◽  
Detailed Comparison ◽  
Radio Sources ◽  
Optical Polarization ◽  
Extragalactic Radio Sources ◽  
Flux Measurements ◽  
Synchrotron Light ◽  
Infrared Frequencies

We presented new observations in various wavebands of those extragalactic radio sources for which the emission of optical synchrotron light is established by polarimetric investigations (jets of M 87 and 3C 273, hot spots in the lobes of 3C 20, 3C 33 and Pictor A). In addition to optical spectral index and polarization maps, we collected flux measurements at radio, millimetre, and near-infrared frequencies. Our observations result in accurate synchrotron spectra between 109 and 1015 Hz. For some sources a detailed comparison between radio and optical polarization is possible.

scholarly journals The Polarization of Extended Radio Sources at 6 cm Wavelength. I. Extragalactic Sources

1971 ◽  
Vol 24 (4) ◽  
pp. 899 ◽  
Author(s):  
FF Gardner ◽  
JB Whiteoak
Keyword(s):  
Magnetic Fields ◽  
Linear Polarization ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Extended Radio

Maps are presented of the linear polarization distributions over eight extragalactic radio sources. They were obtained at 6 cm wavelength with a 4' arc resolution. Low brightness extensions show polarization of up to 70% with magnetic fields aligned perpendicular to their elongations.

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).

scholarly journals 9.10. The cause of the spectral turnover in the GPS source 0108+388: free-free absorption or SSA?

1998 ◽  
Vol 184 ◽  
pp. 401-402
Author(s):  
J. M. Marr ◽  
F. Crawford ◽  
G. B. Taylor
Keyword(s):  
Magnetic Fields ◽  
Radio Source ◽  
High Frequency ◽  
Radio Sources ◽  
Host Galaxies ◽  
Ionized Gas ◽  
High Frequencies ◽  
Extragalactic Radio Sources ◽  
Competing Models ◽  
Frequency Radiation

The radio source 0108 + 388 is a canonical example of a class of extragalactic radio sources, referred to as Gigahertz-Peaked Spectrum (GPS) sources, whose spectra peak at high frequencies. There are two competing models for the cause of the high frequency turnover: free-free absorption (f-f) of the lower frequency radiation by ionized gas in the host galaxies (e.g. van Breugel 1984), or synchrotron self-absorption (SSA) due to exceptionally large magnetic fields, (e.g. Hodges, Mutel, & Phillips 1984).

scholarly journals On the Magnetic Fields of Galaxies

2021 ◽  
pp. 470-477
Author(s):  
R. R. Andreasyan
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Faraday Rotation ◽  
Radio Galaxies ◽  
Morphological Properties ◽  
Radio Sources ◽  
Extragalactic Radio Sources

We bring results of some our investigations of magnetic field of our Galaxy and extragalactic radio sources. For the study were used data of Faraday rotation of pulsars and extragalactic radio sources as well as data of physical and morphological properties of more than 500 radio galaxies of different morphological classes.

scholarly journals Radio Source Evolution and Unified Schemes

1999 ◽  
Vol 16 (2) ◽  
pp. 124-129 ◽  
Author(s):  
C. A. Jackson
Keyword(s):  
Radio Source ◽  
Orientation Dependence ◽  
Observational Evidence ◽  
Line Of Sight ◽  
Radio Sources ◽  
Synchrotron Emission ◽  
Parent Population ◽  
Random Orientation ◽  
Massive Black Hole ◽  
Extragalactic Radio Sources

AbstractPowerful extragalactic radio sources are characterised by kpc-scale synchrotron emission associated with highly-collimated outflows of relativistic plasma. It is hypothesised that this outflowing plasma is powered by accretion processes concomitant with a central massive black hole. The radio morphologies of these sources comprise jets, lobes and for the most powerful sources, hotspots. At first sight, powerful extragalactic radio sources are a mixed group of objects, with the result that only some gross property delineates them further (e.g. steep-spectrum or flat-spectrum). However, there is accumulating observational evidence which suggests that it is the orientation of the radio axis to our line of sight that dictates their observed characteristics. This orientation dependence has been incorporated into ‘unified schemes’, which physically link apparently disparate radio source types via the random orientation of a ‘parent’ population on the plane of the sky. This paper summarises the ‘dual-population unified scheme’ paradigm investigated by Wall & Jackson (1997) and Jackson & Wall (1999) and discusses some of its implications with respect to radio source cosmology.

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