Orientations of radio galaxies

Open Access
Publisher Website
Google Scholar
Abstract
Elliptical galaxies associated with 3CR sources and about 100 other radio sources at declinations δ > + 10° were examined on glass copies of the red plates of the Mount Palomar Sky Survey. The extent and ellipticities of the envelopes of the galaxies were measured, and classifications were derived for the galaxies with known redshifts. Orientations were determined to an accuracy better than ±10° for 40 galaxies, including 22 galaxies measured on copies of both red and blue plates. A search was made for clusters to which the 40 galaxies might belong, and six candidate clusters were found. For the galaxies with published radio maps, the optical orientations were compared with the orientations of the radio axes. The observed radio axes are distributed over all possible orientations, but the majority of them appear orientated within 30° of the minor axes of the galaxies. Data on giant radio sources with projected sizes ≳ 500 kpc were compiled, and precise alignments between large and small radio structures were noted. If such alignments imply formation of radio structures along the rotational or magnetic axes of the nuclei of the parent galaxies, the axes of the nuclei may not be closely related to the orientations of the whole galaxies.

This publication has 0 references indexed in Scilit: