I will talk about the UV galaxies discovered on plates of the 1-m Schmidt telescope of the Byurakan Observatory by Markarian and his collaborators and by Kazarian. Up to now the number of UV galaxies is more than 2000.
It is well known that more than 85% of UV galaxies show emission spectra. Among them there have been discovered OSO's, Seyfert galaxies and galaxies with active nuclei with narrow emission lines. It turns out also that some UV galaxies show spectra typical of superassociations (SA). Some of them really turn out to be SA, connected with nearby galaxies, for example, Markarian 94 (Arp & Khachikian 1974), Markarian 5, 59, 71, 256 (Khachikian & Sahakian 1975). Altogether, in the first six lists of Markarian it has been found about 40 of these types of objects. Contrary to OSO's, Seyferts and narrow emission line galaxies, which have starlike nuclei, the central regions of some other UV galaxies entirely consist of several SA: Markarian 7 (Casini, Heidmann and Tarenghi 1979), Markarian 8 (Khachikian 1972), Markarian 325 (Coupinot, Hecquet and Heidmann 1982), Kazarian 5 (Kazarian & Khachikian 1977). In many cases UV galaxies themselves contain one or more SA: Markarian 12, 38, 307, 848, 984 (Khachikian, Petrossian & Sahakian 1983a). There are case when one or both components of double nucleus UV galaxies have the characteristics of SA: Markarian 104, 306, 111, 710, 739 (Khachikian, Petrossian & Sahakian 1979, 1980a,b; Khachikian, Korovyakovskiy,Petrossian & Sahakian 1981). It is necessary to note just one more type of SA often called ‘isolated giant HII regions’: Markarian 116=IZwl8 (Searle & Sargent 1972). Apparently, among UV galaxies there are quite a number of isolated SA. Actually, they are a particular type of compact galaxies which mainly consist of hot stars and diffuse matter.