Virial mass and kinematics of the Virgo cluster
Abstract
From line of sight velocities of galaxies in the Virgo cluster region given by Binggeli, Sandage and Tammann, 352 member galaxies in central 6°core of the cluster are determined by the maximum likelihood principle. Based on these member galaxies it is obtained that for the cluster the virial mass μν = 2.7×10 14μ⊙, total luminosity LB = 2.0×10 12L⊙, mass-luminosity ratio μ ν/L B = 136 , and luminosity mass μL = 4.1×10 13μ⊙. The velocity dispersion profile of the Virgo cluster is quite similar to that of the Coma, and a tendency of the observed velocity dispersion decreasing towards the cluster center is found. There is a strong morphological segregation in both space and velocity for the cluster members, early-type galaxies being more concentrated towards the cluster center and showing a smaller velocity dispersion than late types ( σ = 615 versus 827 km/ s). It is indicated from discussions on the virial mass and the mass segregation that the period of dynamic evolution when the Virgo cluster has been undergone is relatively quite short, almost no effect of mass segregation is shown, and it should be a young irregular cluster of galaxies.
- Publication:
-
Chinese Astronomy and Astrophysics
- Pub Date:
- September 1992
- DOI:
- 10.1016/0275-1062(92)90065-J
- Bibcode:
- 1992ChA&A..16..257Z
- Keywords:
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- Mass To Light Ratios;
- Radial Velocity;
- Virgo Galactic Cluster;
- Virial Theorem;
- Irregular Galaxies;
- Line Of Sight;
- Maximum Likelihood Estimates;
- Astrophysics;
- Virgo cluster-virial mass-kinematics