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arXiv · 1809.05202

The structure of large-scale stellar disks in cluster lenticular galaxies

Olga K. Sil'chenko·Alexei Yu. Kniazev·Ekaterina M. Chudakova
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Abstract

By obtaining imaging data in two photometric bands for 60 lenticular galaxies - members of 8 southern clusters - with the Las Cumbres Observatory one-meter telescope network, we have analyzed the structure of their large-scale stellar disks. The parameters of radial surface-brightness profiles have been determined (including also disk thickness), and all the galaxies have been classified into pure exponential (Type I) disk surface-brightness profiles, truncated (Type II) and antitruncated (Type III) piecewise exponential disk surface-brightness profiles. We confirm the previous results of some other authors that the proportion of surface-brightness profile types is very different in environments of different density: in the clusters the Type-II profiles are almost absent while according to the literature data, in the field they constitute about one quarter of all lenticular galaxies. The Type-III profiles are equally presented in the clusters and in the field, while following similar scaling relations; but by undertaking an additional structural analysis including the disk thickness determination we note that some Type-III disks may be a combination of a rather thick exponential pseudobulge and an outer Type-I disk. Marginally we detect a shift of the scaling relation toward higher central surface brightnesses for the outer segments of Type-III disks and smaller thickness of the Type-I disks in the clusters. Both effects may be explained by enhanced radial stellar migration during disk galaxy infall into a cluster that in particular represents an additional channel for Type-I disk shaping in dense environments.

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Olga K. Sil'chenko, Alexei Yu. Kniazev, Ekaterina M. Chudakova. 2018-09-13. The structure of large-scale stellar disks in cluster lenticular galaxies. https://doi.org/10.3847/1538-3881%2Faad37b

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