2006/07/31 by W. P. Lin, Weipeng Lin, Y. P. Jing +6 · 4 citations
Physics and Astronomy · #Astrophysics #Baryon #Cosmology and Gravitation Theories #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Physics #Stellar, planetary, and galactic studies #Virial theorem #astro-ph
paper · pdf · doi:10.1086/508052
published as Astrophys.J.651:636-642,2006 · 8 pages, 6 figures, 1 table, ApJ in press (v652n1); updated to match with the being published version
arxiv created 2006/10/09 · openalex publication_date 2006/11/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Using a set of high-resolution N -body/SPH cosmological simulations with identical initial conditions but run with different numerical setups, we investigate the influence of baryonic matter on the mass distribution of dark halos when radiative cooling is not included. We compare the concentration parameters of about 400 massive halos with virial mass from 10 13 to 7.1 × 10 14 h -1 M ☉ . We find that the concentration parameters for the total mass and dark matter distributions in nonradiative simulations are on average larger by ~3% and 10% than those in a pure dark matter simulation. Our results indicate that the total mass density profile is little affected by a hot gas component in the simulations. After carefully excluding the effects of resolutions and spurious two-body heating between dark matter (DM) and gas particles, we conclude that the increase of the DM concentration parameters is due to interactions between baryons and DM. We demonstrate this with the aid of idealized simulations of two-body mergers. The results of individual halos simulated with different mass resolutions show that in the gas profiles of densities, temperature and entropy are subjects of mass resolution of SPH particles. In particular, we find that in the inner parts of halos, as the SPH resolution increases the gas density becomes higher but both the entropy and temperature decrease.