The Effects of Non‐Gaussian Initial Conditions on the Structure and Substructure of Cold Dark Matter Halos

2003/06/30 by V. Avila-Reese, Vladimir Avila‐Reese, Pedro Colin +5 · 1 citation
Physics and Astronomy · #Cold dark matter #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Galaxies: Formation, Evolution, Phenomena #Gaussian #Gravitational potential #Halo #Population #Skewness #Substructure #astro-ph

paper · pdf · doi:10.1086/378773

published as Astrophys.J.598:36-48,2003 · 15 pages, 8 figures. Slight corrections after referee report. To appear in ApJ, v598, November 20, 2003

arxiv created 2003/09/06 · openalex publication_date 2003/11/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/08

Abstract

We study the structure and substructure of halos obtained in N -body simulations for a ΛCDM cosmology with non-Gaussian initial conditions. The initial statistics are lognormal in the gravitational potential field with positive (LN p ) and negative (LN n ) skewness; the sign of the skewness is conserved by the density field, and the power spectrum is the same for all the simulations. Our aim is not to test a given non-Gaussian statistics but to explore the generic effect of positive- and negative-skew statistics on halo properties. From our low-resolution simulations, we find that LN p (LN n ) halos are systematically more (less) concentrated than their Gaussian counterparts. This result is confirmed by our Milky Way- and cluster-sized halos resimulated with high resolution. In addition, they show inner density profiles that depend on the statistics: the innermost slopes of LN p (LN n ) halos are steeper (shallower) than those obtained from the corresponding Gaussian halos. A subhalo population embedded in LN p halos is more susceptible to destruction than its counterpart inside Gaussian halos. On the other hand, subhalos in LN n halos tend to survive longer than subhalos in Gaussian halos. The spin parameter probability distribution of LN p (LN n ) halos is skewed to smaller (larger) values with respect to the Gaussian case. Our results show how the statistics of the primordial density field can influence some halo properties, opening the possibility of constraining, albeit indirectly, the primordial statistics at small scales.

Citations

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• Power spectrum normalization and the non-Gaussian halo model