Evolution of the Merger Induced Hydrostatic Mass Bias in Galaxy Clusters

Details Evolution of the Merger Induced Hydrostatic Mass Bias in Galaxy Clusters Evolution of the Merger Induced Hydrostatic Mass Bias in Galaxy Clusters

2011-12-15

arxiv.org/abs/1112.3659v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

10 pages, 6 figures; Updated to match version accepted by ApJ

Scientific paper

In this work, we examine the effects of mergers on the hydrostatic mass estimate of galaxy clusters using high-resolution Eulerian cosmological simulations. We utilize merger trees to isolate the last merger for each cluster in our sample and follow the time evolution of the hydrostatic mass bias as the systems relax. We find that during a merger, a shock propagates outward from the parent cluster, resulting in an overestimate in the hydrostatic mass bias. After the merger, as a cluster relaxes, the bias in hydrostatic mass estimate decreases but remains at a level of -5-10% with 15-20% scatter within r500. We also investigate the post-merger evolution of the pressure support from bulk motions, a dominant cause of this residual mass bias. At r500, the contribution from random motions peaks at 30% of the total pressure during the merger and quickly decays to \sim 10-15% as a cluster relaxes. Additionally, we use a measure of the random motion pressure to correct the hydrostatic mass estimate. We discover that 4 Gyr after mergers, the direct effects of the merger event on the hydrostatic mass bias have become negligible. Thereafter, the mass bias is primarily due to residual bulk motions in the gas which are not accounted for in the hydrostatic equilibrium equation. We present a hydrostatic mass bias correction method that can recover the unbiased cluster mass for relaxed clusters with 9% scatter at r500 and 11% scatter in the outskirts, within r200.

Affiliated with

Also associated with

No associations

Rating

Evolution of the Merger Induced Hydrostatic Mass Bias in 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 Evolution of the Merger Induced Hydrostatic Mass Bias in Galaxy Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of the Merger Induced Hydrostatic Mass Bias in Galaxy Clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-136064