Galactic satellite systems: radial distribution and environment dependence of galaxy morphology

• Published in: Monthly notices of the Royal Astronomical Society Vol. 389; no. 1; pp. 86 - 92
• Main Authors: Ann, H. B., Park, Changbom, Choi, Yun-Young
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2008; Blackwell Science; Oxford University Press
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; galaxies: formation; galaxies: general; galaxies: interactions; methods: observational; Star & galaxy formation; Stars & galaxies; galaxies: formation; methods: observational; galaxies: general; galaxies: interactions; Radial distribution; High density; Galaxy formation; Morphology; Luminosity; Early type galaxies; Sky surveys
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2008.13581.x

We have studied the radial distribution of the early (E/S0) and late (S/Irr) types of satellites around bright host galaxies. We made a volume-limited sample of 4986 satellites brighter than Mr=−18.0 associated with 2254 hosts brighter than Mr=−19.0 from the Sloan Digital Sky Survey Data Release 5 sample. The morphology of satellites is determined by an automated morphology classifier, but the host galaxies are visually classified. We found segregation of satellite morphology as a function of the projected distance from the host galaxy. The amplitude and shape of the early-type satellite fraction profile are found to depend on the host luminosity. This is the morphology–radius/density relation at the galactic scale. There is a strong tendency for morphology conformity between the host galaxy and its satellites. The early-type fraction of satellites hosted by early-type galaxies is systematically larger than that of late-type hosts, and is a strong function of the distance from the host galaxies. Fainter satellites are more vulnerable to the morphology transformation effects of hosts. Dependence of satellite morphology on the large-scale background density was detected. The fraction of early-type satellites increases in high-density regions for both early- and late-type hosts. It is argued that the conformity in morphology of galactic satellite system is mainly originated by the hydrodynamical and radiative effects of hosts on satellites.