On the Origin of Bias, Scatter, and Evolution in Sunyaev-Zeldovich Effect Scaling Relations
Abstract
In this work, we investigate the impact of cluster mergers on the Sunyaev-Zel’dovich (SZ) effect scaling relation using high-resolution cosmological simulations of 85 galaxy clusters. By following the time evolution of the SZ signal of simulated clusters, we show that the thermal SZ signal increases systematically by ~20% after a major merger, as the kinetic energy of gas motions decays into thermal energy. We find that this evolving thermal energy content contributes to scatter in the SZ observable-mass relation. Once we account for the non-thermal pressure provided by random gas motions, the total SZ signal of relaxed clusters exhibits no systematic evolution and its scatter is roughly halved. We discuss implications of our work in cluster cosmology with ongoing and future SZ surveys and prospects for measuring gas flow in clusters with upcoming X-ray and SZ observations.
- Publication:
-
American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22335820Y