On the Outskirts of Dark Matter Haloes

Abstract

Halo Models of large scale structure provide powerful and indispensable tools for phenomenological understanding of the clustering of matter in the Universe. While the halo model builds structures out of the superposition of haloes, defining halo profiles in their outskirts - beyond their virial radii - becomes increasingly ambiguous, as one cannot assign matter to individual haloes in a clear way. In this paper, we tackle this question by using numerical N-body simulations to find a systematic definition of mean halo profile that can be extended to large radii. These profiles must be compensated and are the key ingredients for the computation of cosmological correlation functions in the Amended Halo Model. The latter, introduced in our earlier work (arXiv:1912.04872), provides a more physically accurate phenomenological description of nonlinear structure formation, which respects conservation laws on large scales. Here, we extend this model from the matter auto-power spectrum to the halo-matter cross-power spectra, using N-body simulations. We find that the (dimensionless) compensated halo profile, $r^3\times \rho (r)/M_{200c}$ has a near-universal maximum in the small range $0.03-0.04$ around the virial radius, $r\simeq r_{200c}$, independent of the halo mass. The profiles cross zero into negative values in the halo outskirts, beyond 2-3$\times r_{200c}$, consistent with our previous results. We provide preliminary fitting functions for compensated Navarro-Frenk-White (NFW) profiles, and this can be used to compute more physical observables in the Amended Halo Model of large scale structure.

arXiv comment11 pages, 5 + 3(appendix) figures. Comments are welcome. Publication in Physical Review D (currently in progress)

References in corpus (22)

• The Structure of Cold Dark Matter Halos
• Efficient Computation of CMB anisotropies in closed FRW models
• Halo Models of Large Scale Structure
• Toward a halo mass function for precision cosmology: the limits of universality
• Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• Revising the Halofit Model for the Nonlinear Matter Power Spectrum
• Halo occupation numbers and galaxy bias
• KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
• Extended Limber Approximation
• The splashback radius as a physical halo boundary and the growth of halo mass
• Halo Assembly Bias in Hierarchical Structure Formation
• Dark Quest. I. Fast and Accurate Emulation of Halo Clustering Statistics and Its Application to Galaxy Clustering
• Towards a self-consistent halo model for the nonlinear large-scale structure
• Extending the modeling of the anisotropic galaxy power spectrum to $k=0.4h{\mathrm{Mpc}}^{-1}$
• Halo Zeldovich model and perturbation theory: dark matter power spectrum and correlation function
• Including beyond-linear halo bias in halo models
• Einasto Profiles and the Dark Matter Power Spectrum
• Shot noise and biased tracers: a new look at the halo model
• The Effective Halo Model: Creating a Physical and Accurate Model of the Matter Power Spectrum and Cluster Counts
• Amending the halo model to satisfy cosmological conservation laws
• Milky Way and M31 rotation curves: $\Lambda$CDM vs. MOND
• The effect of finite halo size on the clustering of neutral hydrogen

Cited by in corpus (1)

• Einasto profile as the halo model solution coupled to the depletion radius