Concentrating the Dark Matter in Galaxy Clusters through Tidal Stripping of Baryonically-Compressed Galactic Halos

Details Concentrating the Dark Matter in Galaxy Clusters through Tidal Stripping of Baryonically-Compressed Galactic Halos Concentrating the Dark Matter in Galaxy Clusters through Tidal Stripping of Baryonically-Compressed Galactic Halos

2009-07-06

arxiv.org/abs/0907.1102v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

7 pages, 3 figures, submitted to MNRAS

Scientific paper

Gravitational lensing observations of massive X-ray clusters imply a steep characteristic density profile marked by a central concentration of dark matter. The observed mass fraction within a projected radius of 150 kpc is twice that found in state-of-the-art dark matter simulations of the standard Lambda-CDM cosmology. A central baryon enhancement that could explain this discrepancy is not observed, leaving a major puzzle. We propose a solution based on the merger histories of clusters. A significant fraction of the final dark matter content of a cluster halo originates within galaxy-sized halos, in which gas can cool and compress the dark matter core to high densities. The subsequent tidal stripping of this compressed dark matter occurs in denser regions that are closer to the center of the cluster halo. Eventually, the originally cooled gas must be dispersed into the intracluster medium through feedback, for consistency with observations that do not find central baryon enhancements in clusters. Still, the early adiabatic compression of the galactic dark matter leaves a net effect on the cluster. Using a simple model for this process, we show that the central cluster profile is substantially modified, potentially explaining the observed discrepancy.

Affiliated with

Also associated with

No associations

Rating

Concentrating the Dark Matter in Galaxy Clusters through Tidal Stripping of Baryonically-Compressed Galactic Halos 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 Concentrating the Dark Matter in Galaxy Clusters through Tidal Stripping of Baryonically-Compressed Galactic Halos, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Concentrating the Dark Matter in Galaxy Clusters through Tidal Stripping of Baryonically-Compressed Galactic Halos will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-355179