The Shapes of Galaxy Clusters

Details The Shapes of Galaxy Clusters The Shapes of Galaxy Clusters

1994-09-06

arxiv.org/abs/astro-ph/9409011v1

Astronomy and Astrophysics

Astrophysics

17 pages, postscript, submitted to MNRAS

Scientific paper

We have reanalyzed a data set of 99 low redshift ($ z < 0.1 $) Abell clusters and determined their shapes. For this, three different measures are used. We use Monte-Carlo simulations to investigate the errors in the methods. The corrected distribution of cluster ellipticities shows a peak at $ \epsilon \sim 0.4 $ and extends to $ \epsilon \sim 0.8 $. The results are self-consistent, i.e., with the corrected distribution over projected cluster shapes we can reconstruct the observed distribution and the observed relation between the number of galaxies in a cluster and its ellipticity. It is shown that the richer clusters are intrinsically more nearly spherical than the poorer ones. The corrected distribution of cluster shapes is more consistent with a prolate population than with an oblate population. We compare the corrected true distribution of (projected) ellipticities with predictions from N-body simulations. For this, we use a catalogue of 75 N-body simulated clusters (van Kampen 1994) which assume a CDM spectrum with $ \Omega = 1.0 $. The simulations include a recipe for galaxy formation and merging. 'Observing' these simulated clusters produces an ellipticity distribution that extends to much higher $ \epsilon $ and that has too few nearly spherical clusters. Preliminary results of simulations of the formation of clusters in an $ \Omega = 0.2 $ universe suggest that, on average, clusters are more nearly spherical in this case.

Affiliated with

Also associated with

No associations

Rating

The Shapes of Galaxy Clusters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Shapes of Galaxy Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Shapes of Galaxy Clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-702167