1996/10/22 by A. Biviano, Biviano, A., P. Katgert +12
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9610168
23 LaTeX pages, 13 figures, to be published in A&A; uuencoded compressed ps file also available at ftp://132.229.8.14/
arxiv created 1996/10/22 · openalex publication_date 1996/10/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/27 · openalex updated_date 2026/07/28
We have studied the frequency of occurrence, the kinematics and the spatial\ndistribution of Emission-Line Galaxies (ELG) in clusters in the ESO Nearby\nAbell Cluster Survey (ENACS). More than 90% of the ELG are spirals, but the ELG\nrepresent only 30% of all spirals. The true ELG fraction in clusters is 0.10;\nthis is consistent with that in the field (0.21) as a result of differences in\nmorphological mix. The average ELG fraction decreases with increasing velocity\ndispersion of the cluster. Only 1/5 of the clusters shows a significant\ndifference in the average velocities of the ELG and the other (non-ELG)\ngalaxies; in a similar fraction of the clusters significant differences in\nvelocity dispersion are seen. Yet, the velocity dispersion of the ELG is, on\naverage, 20% larger than that of the non-ELG. This larger velocity dispersion\nis largely intrinsic, i.e. it is not likely to be the result of velocity\noffsets of the ELG. The surface density of the ELG is significantly less peaked\ntowards the centre than that of the non-ELG. The ELG are distributed fairly\nsmoothly within the cluster with at most 25% in compact substructures. The\ndistribution and kinematics of the ELG yield virial mass estimates that, on\naverage, are 50% higher than those based on the non-ELG. This probably means\nthat the ELG are on more radial orbits than the non-ELG. All observed\nproperties of the ELG are consistent with most of them being on their first\napproach of the high-density cluster core.\n