Рeculiar galaxies. Оbservations and results of the galaxy NGC 474

Nikola Karavassilev, Momchil Molnar

Abstract

In the article, the galaxies, characterized as peculiar, are discussed. First, we describe the normal galaxies and their morphological classification. The difference between the irregular and peculiar galaxies is clarified. After that, the catalog of Halton Arp, containing 338 peculiar galaxies. We made a detailed overview of the four types of galactic peculiarities. The second part of the article is devoted to the galaxy NGC 474, which belongs to the shell galaxies. After the general information about it, we present our observations and results, paying special attention to the surface photometry we have made. The profile of the surface brightness as a function of the distance from the galaxy center is in a complete accordance with the theoretical predictions. We also present the variation of the color indexes with this distance. Based on these results we make an assumption about the origin of the shells around it.