Effects of Baryons and Dissipation on the Matter Power Spectrum

Abstract

We study the importance of baryonic physics on predictions of the matter power spectrum as it is relevant for forthcoming weak lensing surveys. We quantify the impact of baryonic physics using a set of three cosmological numerical simulations. Each simulation has the same initial density field, but models a different set of physical processes. The first simulation evolves the density field using gravity alone, the second includes non-radiative gasdynamics, and the third includes radiative heating and cooling of baryons, star formation, and supernova feedback. We find that baryonic processes alter predictions for the matter power spectrum significantly relative to models that include only gravitational interactions. Our results imply that future weak lensing experiments such as LSST and SNAP will be very sensitive to the poorly-understood physics governing the nonlinear evolution of the baryonic component of the universe. The net effect is significantly larger in the case of the model with cooling and star formation, in which case our results imply that contemporary surveys such as the CFHT Wide survey may also be sensitive to baryonic processes. In particular, this effect could be important for forecasts of the constraining power of future surveys if information from scales larger than l ~ 1000 is included in the analysis. We find that deviations are caused primarily by the rearrangement of matter within individual dark matter halos relative to the gravity-only case, rather than a large-scale rearrangement of matter. Consequently, we propose a simple model, based on the phenomenological halo model of dark matter clustering, for baryonic effects that can be used to aid in the interpretation of forthcoming weak lensing data.

14 pages, 8 figures. Submitted to ApJ

References in corpus (8)

• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• The Excursion Set Theory of Halo Mass Functions, Halo Clustering, and Halo Growth
• The Observed Concentration-Mass Relation for Galaxy Clusters
• The X-Ray Concentration-Virial Mass Relation
• Intracluster light and the extended stellar envelopes of cD galaxies: An analytical description
• The baryon fraction of LambdaCDM haloes
• Missing Thermal Energy of the Intracluster Medium
• Dark and baryonic matter in the MareNostrum Universe

Cited by in corpus (10)

• Non-linear Evolution of f(R) Cosmologies III: Halo Statistics
• The Cosmic Code Comparison Project
• Finding Evidence for Massive Neutrinos using 3D Weak Lensing
• Dark Energy Constraints from Galaxy Cluster Peculiar Velocities
• The Effect of Gas Physics on the Halo Mass Function
• Distance, Growth Factor, and Dark Energy Constraints from Photometric Baryon Acoustic Oscillation and Weak Lensing Measurements
• Size of spectroscopic calibration samples for cosmic shear photometric redshifts
• Observational constraints on the braneworld model with brane-bulk energy exchange
• Signatures of the Baryon Acoustic Oscillations on the Convergence Power Spectrum of Weak lensing by Large Scale Structure
• Systematic Errors in Sunyaev-Zeldovich Surveys of Galaxy Cluster Velocities