Cosmic Reionization On Computers: Baryonic Effects on Halo Concentrations During the Epoch of Reionization

Abstract

Baryons both increase halo concentration through adiabatic contraction and expel mass through feedback processes. However, it is not well understood how the radiation fields prevalent during the epoch of reionization affect the evolution of concentration in dark matter halos. We investigate how baryonic physics during the epoch of reionization modify the structure of dark matter halos in the Cosmic Reionization On Computers (CROC) simulations. We use two different measures of halo concentration to quantify the effects. We compare concentrations of halos matched between full physics simulations and dark-matter-only simulations with identical initial conditions between $5\le z\le 9$. Baryons in full physics simulations do pull matter towards the center, increasing the maximum circular velocity compared to dark-matter-only simulations. However, their overall effects are much less than if all the baryons were simply centrally concentrated indicating that heating processes efficiently counteract cooling effects. Finally, we show that the baryonic effects on halo concentrations at $z\approx 5$ are relatively insensitive to environmental variations of reionization history. These results are pertinent to models of galaxy-halo connection during the epoch of reionization.

arXiv comment9 pages, 7 figures, comments are welcome

References in corpus (36)

• A Universal Density Profile from Hierarchical Clustering
• Profiles of dark haloes: evolution, scatter, and environment
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• Concentrations of Dark Halos from their Assembly Histories
• At the heart of the matter: the origin of bulgeless dwarf galaxies and Dark Matter cores
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Halos and galaxies in the standard cosmological model: results from the Bolshoi simulation
• Response of dark matter halos to condensation of baryons: cosmological simulations and improved adiabatic contraction model
• How supernova feedback turns dark matter cusps into cores
• Halo concentrations in the standard LCDM cosmology
• Massloss of galaxies due to a UV-background
• Accurate universal models for the mass accretion histories and concentrations of dark matter halos
• Baryon effects on the internal structure of LCDM halos in the EAGLE simulations
• A universal model for halo concentrations
• Why Baryons Matter: The Kinematics of Dwarf Spheroidal Satellites
• The Mass-Concentration-Redshift Relation of Cold Dark Matter Halos
• Mass and Redshift Dependence of Dark Halo Structure
• Galaxy-Induced Transformation of Dark Matter Halos
• Maximum Feedback and Dark Matter Profiles of Dwarf Galaxies
• Baryonic Pinching of Galactic Dark Matter Halos
• Cosmic Reionization On Computers I. Design and Calibration of Simulations
• The Compression of Dark Matter Halos by Baryonic Infall
• The effects of baryon physics, black holes and AGN feedback on the mass distribution in clusters of galaxies
• Cosmic Reionization On Computers II. Reionization History and Its Back Reaction on Early Galaxies
• The Copernicus Complexio: a high-resolution view of the small-scale Universe
• Concentrations of Dark Haloes Emerge from Their Merger Histories
• Active galactic nuclei and massive galaxy cores
• Subhalo Demographics in the Illustris Simulation: Effects of Baryons and Halo-to-Halo Variation
• How Biased Are Halo Properties in Cosmological Simulations?
• The impact of baryons on dark matter haloes
• Dark-ages Reionization & Galaxy Formation Simulation II: Spin and concentration parameters for dark matter haloes during the Epoch of Reionization
• The impact of baryonic physics on the abundance, clustering, and concentration of halos
• Moderate Steepening of Galaxy Cluster Dark Matter Profiles by Baryonic Pinching
• Cosmic Reionization On Computers: Numerical and Physical Convergence
• Cosmic Reionization On Computers: The Galaxy-Halo Connection between $5\le z\le 10$
• Cosmic Reionization On Computers: Reionization Histories of Present-day Galaxies