2007/04/30 by A. Faltenbacher, Cheng Li, Shude Mao +7 · 2 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy group #Geometry #Halo #Orientation (vector space) #Physics #Redshift #Satellite #Satellite galaxy #Sky #Weak gravitational lensing #astro-ph
paper · pdf · doi:10.1086/519683
4 pages, 4 figures, ApJL accepted
openalex publication_date 2007/06/06 · arxiv created 2007/06/08 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/06
Using a large galaxy group catalog based on the Sloan Digital Sky Survey Data Release 4, we measure three different types of intrinsic galaxy alignment within groups: halo alignment between the orientation of the brightest group galaxies (BGG) and the distribution of its satellite galaxies, radial alignment between the orientation of a satellite galaxy and the direction toward its BGG, and direct alignment between the orientation of the BGG and that of its satellites. In agreement with previous studies, we find that satellite galaxies are preferentially located along the major axis. In addition, on scales r < 0.7 R vir we find that red satellites are preferentially aligned radially with the direction to the BGG. The orientations of blue satellites, however, are perfectly consistent with being isotropic. Finally, on scales r < 0.1 R vir , we find a weak but significant indication for direct alignment between satellites and BGGs. We briefly discuss the implications for weak-lensing measurements.