Formation and Structure of Halos in a Warm Dark Matter Cosmology

By V. Avila-Reese, P. Colín, Octavio Valenzuela, E. D’Onghia, C. Firmani. 2000

195 citations recorded by the source corpus.

Using high-resolution cosmological N-body simulations, we study how the density profiles of dark matter halos are affected by the filtering of the density power spectrum below a given scale length and by the introduction of a thermal velocity dispersion. In the warm dark matter (WDM) scenario, both the free-streaming scale, Rf, and the velocity dispersion, v, are determined by the mass, mW, of the WDM particle. We found that v is too small to affect the density profiles of WDM halos. Down to the resolution attained in our simulations (~0.01 virial radii), there is not any significant difference in the density profiles and concentrations of halos obtained in simulations with and without the inclusion of v. Resolved soft cores appear only when we artificially increase the thermal velocity dispersion to a value that is much higher than v. We show that the size of soft cores in a monolithic collapse is related to the tangential velocity dispersion. The density profiles of the studied halos with masses down to ~0.01 the filtering mass Mf can be described by the Navarro-Frenk-White shape; soft cores are not formed. Nevertheless, the concentrations of these halos are lower than those of the CDM counterparts and are approximately independent of mass. The cosmogony of halos with masses ≲Mf is not hierarchical: they form through monolithic collapse and by fragmentation of larger structures. The formation epoch of these halos is slightly later than that of halos with masses ≈Mf. The lower concentrations of WDM halos with respect to their CDM counterparts can be accounted for by their late formation epoch. Overall, our results point to a series of advantages of a WDM model over the CDM one. In addition to solving the substructure problem, a WDM model with Rf ~ 0.16 Mpc (mW ≈ 0.75 keV; flat cosmology with ΩΛ = h = 0.7) also predicts concentrations, a Tully-Fisher relation, and formation epochs for small halos, which seems to be in better agreement with observations than CDM predictions.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a2d94fdf60520958eb1289c1bcf170565a8e4dda

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Citations in the corpus

The stellar mass-halo mass relation of isolated field dwarfs : a critical test of ΛCDM at the edge of galaxy formation (2016, unknown): “MNRAS 000, 000–000 (0000) and at early times (e.g. Bode et al. 2001; Avila-Reese et al. 2001).”
The shape of dark matter haloes in the Aquarius simulations: evolution and memory (2011, unknown): “E-mail: cavera@astro.rug.nl 2000; Avila-Reese et al. 2001; Strigari et al. 2007; Wang & White 2009).”
Dark matter and visible baryons in M33 (2003, background): “(5) Numerical simulations of galaxy formation in CDM models find a correlation between ρNFW and RNFW which depends on the cosmological model (Avila-Reese et al. 2001; Eke, Navarro & Steinmetz 2001).”
Cuspy No More: How Outflows Affect the Central Dark Matter and Baryon Distribution in Lambda CDM Galaxies (2012, background): “…constraint for all models of galaxy formation and can be interpreted assuming a truncation in the halo mass function as predicted in WDM models (Avila-Reese et al. 2001; Bode et al. 2001; Boylan-Kolchin et al. 2011b; Parry et al. 2011; Schneider et al. 2011) or to the suppression of SF in…”
Galaxy Rotation Curves without Nonbaryonic Dark Matter (2005, background): “During the last two decades of numerical modeling of galaxy formation, they have produced a density profile of dark matter halos / 1/r3 at large radii, which BROWNSTEIN & MOFFAT736 Vol. 636 does not depend on the nature of the dark matter (Avila-Reese et al. 2001; Colin et al. 2002).”
The local dark matter density (2014, background): “That said, problems still remain for simulations where there is a strong suppression in the small scale power spectrum, as in WDM simulations (Bode et al., 2001; Avila-Reese et al., 2001; Wang & White, 2007; Hahn et al., 2013).”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, background): “Warm dark matter (WDM) suppresses the growth of structure in the early universe producing a measurable effect on the small-scale matter power spectrum [143, 67, 87].”
Halo Substructure and the Power Spectrum (2002, methodology): “The B01 model reproduces N-body results for n = 1, n = 0.9, and power-law CDM models (e.g., Coĺın et al. 2000b; B01) as well the WDM simulations of Coĺın et al. (2000a) and Avila-Reese et al. (2001).”
The properties of warm dark matter haloes (2013, background): “The trends seen in Figs 17 and 18 reflect the fact that, for fixed cosmological parameters, haloes of a given mass form later in WDM models than in CDM (Avila-Reese et al. 2001; Lovell et al. 2012).”
The warm dark matter halo mass function below the cut-off scale (2013, background): “This phenomenon originates in the numerical (unphysical) fragmentation of filaments, and it exceeds by far the population of real WDM haloes on scales near the cut-off scale (see e.g. Avila-Reese et al. 2001; Bode et al. 2001; Wang & White 2007; Melott 2007).”
Non-linear evolution of cosmological structures in warm dark matter models (2011, methodology): “…structure formation in the WDM model (Colombi, Dodelson & Widrow 1996; Moore et al. 1999; Colı́n, Avila-Reese & Valenzuela 2000; White & Croft 2000; Avila-Reese et al. 2001; Bode et al. 2001; Bullock, Kravtsov & Colı́n 2002; Zentner & Bullock 2003; Colı́n, Valenzuela & Avila-Reese 2008; Zavala…”
The dependence of dark matter profiles on the stellar-to-halo mass ratio: a prediction for cusps versus cores (2013, background): “One possibility, without resorting to more exotic forms of dark matter (e.g. warm dark matter see Avila-Reese et al. 2001; Bode et al. 2001; Knebe et al. 2002, Macciò et al. 2012b), is that this inconsistency arises from having neglected the effects of baryons, which are irrelevant on cosmological…”
Concentrations of Dark Halos from Their Assembly Histories (2001, unknown): “…truncated power spectra, in which there is no systematic relation between collapse time and halo mass, no correlation is seen between mass and cvir (Avila-Reese et al. 2001; Bode, Ostriker, & Turok 2001; Eke, Navarro, & Steinmetz 2001). the model proposed by B01, and develop a physical model for…”