Core formation in dwarf haloes with self-interacting dark matter: no fine-tuning necessary

By Oliver D. Elbert, James S. Bullock, S. Garrison-Kimmel, Miguel Rocha, J. Oñorbe, A. Peter. 2014

256 citations recorded by the source corpus.

Author(s): Elbert, OD; Bullock, JS; Garrison-Kimmel, S; Rocha, M; Onorbe, J; Peter, AHG | Abstract: © 2015 The Authors. We investigate the effect of self-interacting dark matter (SIDM) on the density profiles of Vmax ≃ 40km s-1 isolated dwarf dark matter haloes-the scale of relevance for the too big to fail problem (TBTF)-using very high resolution cosmological zoom simulations. Each halo has millions of particles within its virial radius. We find that SIDM models with cross-sections per unitmass spanning the range s/m=0.5-50 cm2 g-1 alleviate TBTF and produce constantdensity cores of size 300-1000 pc, comparable to the half-light radii of M* ~ 105-7M⊙ dwarfs. The largest, lowest density cores develop for cross-sections in the middle of this range, σ/m ~ 5-10 cm2 g-1. Our largest SIDM cross-section run (σ/m = 50 cm2 g-1) develops a slightly denser core owing to mild core-collapse behaviour, but it remains less dense than the cold dark matter case and retains a constant-density core profile. Our work suggests that SIDM cross-sections as large or larger than 50 cm2 g-1 remain viable on velocity scales of dwarf galaxies (vrms ~ 40 km s-1). The range of SIDM cross-sections that alleviate TBTF and the cusp/core problem spans at least two orders of magnitude and therefore need not be particularly fine-tuned.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/965e6c9acd4d2b63328aeff3abea32ebed27170f

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Citations in the corpus

The impact of baryonic physics on the structure of dark matter haloes: the view from the FIRE cosmological simulations (2015, background): “…scale structure (Abazajian 2006; Dunstan et al. 2011; Lovell et al. 2012) and self-interacting dark matter (SIDM) whose interaction can substantially affect the central density profile of halos (e.g. Yoshida et al. 2000; Burkert 2000; Kochanek & White 2000; Davé et al. 2001; Elbert et al. 2015).”
Dark matter cores all the way down (2015, background): “…by pure collisionless cold dark matter structure formation simulations (e.g. Dubinski & Carlberg 1991; Navarro et al. 1996b; Springel et al. 2008; Stadel et al. 2009), which has led many to claim that this is evidence for new physics3 (e.g. Moore 1994; Rocha et al. 2013; Elbert et al. 2015).”
Gravitational probes of dark matter physics (2017, methodology): “If the density profiles are modified by physics which is not correctly modeled by the CDM-only simulations, the matching between v1/2 and Mvir changes significantly [224, 221, 261, 285].”
Small-Scale Challenges to the ΛCDM Paradigm (2017, background): “…matter cores in dwarf galaxies with sizes ∼ 0.3− 1.5 kpc and central densities 2 − 0.2 × 108 M kpc−3 = 7.4 − 0.74 GeV cm−3 that can alleviate the cusp/core and toobig-to-fail problems discussed above (e.g., Vogelsberger, Zavala & Loeb 2012; Peter et al. 2013; Fry et al. 2015; Elbert et al. 2015).”