Association of Pairs of Radio Sources with Peculiar Galaxies

Abstract

Arp (1967) argued that there exists a definite association between radio sources and peculiar galaxies of his earlier paper (Arp, 1966). He advocated that for two radio sources lying relatively close to one another, and often possessing similar radio brightness or flux strength, there exists a peculiar galaxy, approximately equidistant from each and unusually close to the line joining the pair, forming an angle of approximately 180°. This is true for particular peculiar galaxies, but can be supported as a general theory only by randomly selecting a sample area of the sky and studying the objects therein. The area was centred on the celestial equator between right ascension (“longitude”) 10h and 16h, and between declination (“latitude”) -16° and +16°, thus avoiding any curvature effect of the lines of right ascension. All peculiar galaxies and radio sources within the boundaries were enumerated and the distances, r _l , from each galaxy to the nearest source, and r ₂ , to the second nearest source, are recorded in degrees in Table 21.1. The radio brightnesses, s ₁ and s ₂, of the closest and second closest radio sources, respectively, are also given. Object numbers are denoted by N, ranging from 1 to 33 for peculiar galaxies, and from 34 to 56 for radio sources.