WHY BARYONS MATTER: THE KINEMATICS OF DWARF SPHEROIDAL SATELLITES

By A. Brooks, A. Zolotov. 2012

244 citations recorded by the source corpus.

We use high-resolution cosmological simulations of Milky Way (MW) mass galaxies that include both baryons and dark matter (DM) to show that baryonic physics (energetic feedback from supernovae and subsequent tidal stripping) significantly reduces the DM mass in the central regions of luminous satellite galaxies. The reduced central masses of the simulated satellites reproduce the observed internal dynamics of MW and M31 satellites as a function of luminosity. We use these realistic satellites to update predictions for the observed velocity and luminosity functions of satellites around MW-mass galaxies when baryonic effects are accounted for. We also predict that field dwarf galaxies in the same luminosity range as the MW classical satellites should not exhibit velocities as low as the satellites because the field dwarfs do not experience tidal stripping. Additionally, the early formation times of the satellites compared to field galaxies at the same luminosity may be apparent in the star formation histories of the two populations. Including baryonic physics in cold dark matter (CDM) models naturally explains the observed low DM densities in the MWs dwarf spheroidal population. Our simulations therefore resolve the tension between kinematics predicted in CDM theory and observations of satellites, without invoking alternative forms of DM.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/3d1b79f2490902f9baef93b974f8a4a12ede2b9e

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Citations in the corpus

Too big to fail in the Local Group (2014, background): “…ram pressure stripping, and tidal interactions, may account for the discrepancy (e.g. Del Popolo 2012; Pontzen & Governato 2012; Zolotov et al. 2012; Brooks et al. 2013; Gritschneder & Lin 2013; Amorisco, Zavala & de Boer 2014; Arraki et al. 2014; Brooks & Zolotov 2014; Del Popolo et al. 2014).”
RECONCILING DWARF GALAXIES WITH ΛCDM COSMOLOGY: SIMULATING A REALISTIC POPULATION OF SATELLITES AROUND A MILKY WAY–MASS GALAXY (2016, background): “…and with more realistic stellar physics (e.g., Hopkins et al. 2014; Agertz & Kravtsov 2015; Mollitor et al. 2015), and some simulations have started to resolve the more massive satellite galaxies within MW-mass halos, with promising results (e.g., Brooks & Zolotov 2014; Sawala et al. 2016).”
The impact of baryonic physics on the structure of dark matter haloes: the view from the FIRE cosmological simulations (2015, background): “There are hints that feedback can help solve this issue along with the cusp/core problem (Madau et al. 2014; Brooks & Zolotov 2014; Oñorbe et al. 2015), although proper statistics are still lacking.”
Gravitational probes of dark matter physics (2017, background): “lower central density of subhalos in hydrodynamic simulations makes satellite galaxies more vulnerable to tidal heating or disruption [385, 372, 225, 143, 386].”
Small-Scale Challenges to the ΛCDM Paradigm (2017, background): “…simulations7), and these environmental influences are often invoked in explaining too-big-to-fail (e.g., Zolotov et al. 2012; Arraki et al. 2014; Brooks & Zolotov 2014; Brook & Di Cintio 2015; Wetzel et al. 2016; Tomozeiu, Mayer & Quinn 2016; Sawala et al. 2016; Dutton et al. 2016).”
Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption (2018, background): “…on how baryons may impact the abundance and demographics of dark matter substructure(e.g., Macciò et al. 2006; Weinberg et al. 2008; Dolag et al. 2009; Arraki et al. 2014; Brooks & Zolotov 2014; Despali & Vegetti 2016; Fiacconi et al. 2016; Wetzel et al. 2016; Garrison-Kimmel et al. 2017).”
Core formation in dwarf haloes with self-interacting dark matter: no fine-tuning necessary (2014, background): “Others have suggested environmental effects may increase the efficacy of these internal processes by similarly reducing the central masses of subhalos (e.g. Zolotov et al., 2012; Del Popolo, 2012; Arraki et al., 2014; Brooks & Zolotov, 2014; Del Popolo et al., 2014).”
Physical Models of Galaxy Formation in a Cosmological Framework (2014, background): “As a bonus, Brooks & Zolotov (2014) have shown that destroying the central cusps in dwarf galaxies leads to enhanced tidal stripping of satellites.”
New Constraints on the free-streaming of warm dark matter from intermediate and small scale Lyman-$\alpha$ forest data (2017, background): “However, apart from changing the nature of the DM several studies have shown that baryonic physics could help in alleviating or even solving the small scale tensions [27,28].”
The SAGA Survey. I. Satellite Galaxy Populations around Eight Milky Way Analogs (2017, background): “It has been suggested that a realistic treatment of baryonic physics and the stochastic nature of star formation can fix these discrepancies (e.g., Brooks & Zolotov 2014; Guo et al. 2015; Wetzel et al. 2016; Brooks et al. 2017).”
Small scale problems of the $\Lambda$CDM model: a short review (2016, methodology): “(b) Photo-ionisation [74,393], and (c) Reionisation.”
Forged in FIRE: cusps, cores and baryons in low-mass dwarf galaxies (2015, background): “We have not considered the effects stripping from ram pressure and tides, that may be important for some Milky Way subhalos (Read et al. 2006; Zolotov et al. 2012; Brooks & Zolotov 2014).”
The upper bound on the lowest mass halo (2016, background): “…have now demonstrated, a significant fraction of model satellites can be wiped out due to the coupling between the stellar feedback, which would loosen the dwarf DM distribution, and the repeated battering by the disk shocks (see e.g. Geen et al. 2013; Brooks & Zolotov 2014; Wetzel et al. 2016).”
Is there a "too big to fail" problem in the field? (2014, background): “3 in Brooks & Zolotov 2014).”