The Effects of Substructure on Dynamical Studies of Galaxy Clusters

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Session 53 -- Clusters of Galaxies I
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

[53.04] The Effects of Substructure on Dynamical Studies of Galaxy Clusters

Christina M. Bird (Univ. of Kansas)

Ongoing optical and X-ray studies of clusters of galaxies reveal that deviations from a smooth, relaxed distribution of galaxies and gas are common, if not ubiquitous. The claim has been made that in most cases, the ``contaminating'' structures are only a small fraction of the total mass of the system, and therefore that their effect on dynamical analyses can be ignored. In this poster I will demonstrate that even when the contaminating subclusters are low mass (and unlikely to have a significant effect on the overall cluster gravitational potential), their presence can greatly modify kinematic and dynamical quantities, such as the velocity dispersion and projected mass estimator. In addition I present distributions of velocity dispersion and dynamical masses for clusters which possess central dominant galaxies, and a re-evaluation of the velocity dispersion-temperature correlation based on this dataset.

Tuesday program listing