Open AccessThe alignment between the distribution of satellites and the orientation of their central galaxy
Author(s) -
Yang Xiaohu,
Van Den Bosch Frank C.,
Mo H. J.,
Mao Shude,
Kang Xi,
Weinmann Simone M.,
Guo Yicheng,
Jing Y. P.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10373.x
Subject(s) - physics , satellite galaxy , astrophysics , galaxy group , astronomy , sky , galaxy , interacting galaxy , brightest cluster galaxy , lenticular galaxy , halo , type cd galaxy , satellite , galaxy formation and evolution
We use galaxy groups selected from the Sloan Digital Sky Survey to examine the alignment between the orientation of the central galaxy (defined as the brightest group member) and the distribution of satellite galaxies. By construction, we therefore only address the alignment on scales smaller than the halo virial radius. We find a highly significant alignment of satellites with the major axis of their central galaxy. This is in qualitative agreement with the recent study of Brainerd, but inconsistent with several previous studies who detected a preferential minor‐axis alignment. The alignment strength in our sample is strongest between red central galaxies and red satellites. On the contrary, the satellite distribution in systems with a blue central galaxy is consistent with isotropic. We also find that the alignment strength is stronger in more massive haloes and at smaller projected radii from the central galaxy. In addition, there is a weak indication that fainter (relative to the central galaxy) satellites are more strongly aligned. We present a detailed comparison with previous studies, and discuss the implications of our findings for galaxy formation.