2003/10/24 by G. A. Mamon, T. Sanchis, Teresa Sanchis +4 · 2 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1051/0004-6361:20034155
published as Astron.Astrophys. 414 (2004) 445-451 · A&A, in press. 8 pages LaTeX2e with 1 figure
arxiv created 2003/10/24 · openalex publication_date 2003/10/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Spiral galaxies that are deficient in neutral Hydrogen are observed on the outskirts of the Virgo cluster. If their orbits have crossed the inner parts of the cluster, their interstellar gas may have been lost through ram pressure stripping by the hot X-ray emitting gas of the cluster. We estimate the maximum radius out to which galaxies can bounce out of a virialized system using analytical arguments and cosmological N-body simulations. In particular, we derive an expression for the turnaround radius in a flat cosmology with a cosmological constant that is simpler than previously derived expressions. We find that the maximum radius reached by infalling galaxies as they bounce out of their cluster is roughly between 1 and 2.5 virial radii. Comparing to the virial radius of the Virgo cluster, which we estimate from X-ray observations, these HI-deficient galaxies appear to lie significantly further away from the cluster center. Therefore, if their distances to the cluster core are correct, the HI-deficient spiral galaxies found outside of the Virgo cluster cannot have lost their gas by ram pressure from the hot intracluster gas.