Halo Density Reduction by Baryonic Settling?

Jardel, John R.; Sellwood, J. A.

doi:10.1088/0004-637x/691/2/1300

Cited by 37 publications

(49 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This would flatten the inner density profile of the dark matter halo (Navarro et al 1996b;Gnedin & Zhao 2002;Read & Gilmore 2005;Mashchenko et al 2006Mashchenko et al , 2008Ogiya & Mori 2011, 2014Governato et al 2012;Macciò et al 2012;Teyssier et al 2013;Oñorbe et al 2015;Chan et al 2015;El-Zant et al 2016;Del Popolo & Pace 2016). On the other hand, dark matter can also be gravitationally "heated" by baryons through dynamical friction caused either by selfgravitating gas clouds orbiting near the center of the galaxy (El-Zant et al 2001, El-Zant et al 2004Jardel & Sellwood 2009;Lackner & Ostriker 2010;Cole et al 2011, Del Popolo & Pace 2016 by the presence of a stellar bar (Weinberg & Katz 2002;Holley-Bockelmann et al 2005;Sellwood 2008), by the radiation recoil from coalescing black holes (Merritt et al 2004), or by processes which transfer of angular momentum from baryonic to dark matter (Tonini et al 2006, Del Popolo 2009, 2012, 2014.…”

Section: Introductionmentioning

confidence: 99%

Density profile of dark matter haloes and galaxies in the horizon–agn simulation: the impact of AGN feedback

Peirani

Dubois

Volonteri

et al. 2017

Monthly Notices of the Royal Astronomical Society

148

141

View full text Add to dashboard Cite

Using a suite of three large cosmological hydrodynamical simulations, HORIZON-AGN, HORIZON-NOAGN (no AGN feedback) and HORIZON-DM (no baryons), we investigate how a typical sub-grid model for AGN feedback affects the evolution of the inner density profiles of massive dark matter haloes and galaxies. Based on direct object-to-object comparisons, we find that the integrated inner mass and density slope differences between objects formed in these three simulations (hereafter, H AGN , H noAGN and H DM ) significantly evolve with time. More specifically, at high redshift (z ∼ 5), the mean central density profiles of H AGN and H noAGN dark matter haloes tend to be much steeper than their H DM counterparts owing to the rapidly growing baryonic component and ensuing adiabatic contraction. By z ∼ 1.5, these mean halo density profiles in H AGN have flattened, pummelled by powerful AGN activity ("quasar mode"): the integrated inner mass difference gaps with H noAGN haloes have widened, and those with H DM haloes have narrowed. Fast forward 9.5 billion years, down to z = 0, and the trend reverses: H AGN halo mean density profiles drift back to a more cusped shape as AGN feedback efficiency dwindles ("radio mode"), and the gaps in integrated central mass difference with H noAGN and H DM close and broaden respectively. On the galaxy side, the story differs noticeably. Averaged stellar profile central densities and inner slopes are monotonically reduced by AGN activity as a function of cosmic time, resulting in better agreement with local observations.

show abstract

Section: Introductionmentioning

confidence: 99%

Density profile of dark matter haloes and galaxies in the horizon–agn simulation: the impact of AGN feedback

Peirani

Dubois

Volonteri

et al. 2017

Monthly Notices of the Royal Astronomical Society

148

141

View full text Add to dashboard Cite

show abstract

“…This process can increase the density of dark matter haloes by an order of magnitude. In contrast, other processes can cause the dark matter halo to expand: rapid mass-loss and/or time variability of the potential due to feedback from stars (Navarro et al 1996;Read & Gilmore 2005;Mashchenko et al 2006;Macciò et al 2012;El-Zant et al 2016) or Active Galactic Nuclei (AGN; Martizzi et al 2012Martizzi et al , 2013; mergers and stripping of smaller subhaloes that were puffed up by stellar feedback (Dekel et al 2003); and transfer of energy/angular momentum from baryons to the dark matter via dynamical friction due to minor mergers (El-Zant et al 2001;Jardel & Sellwood 2009;Johansson et al 2009;Cole et al 2011), or galactic bars (Weinberg & Katz 2002;Sellwood 2008).…”

Section: Introductionmentioning

confidence: 99%

NIHAO IX: the role of gas inflows and outflows in driving the contraction and expansion of cold dark matter haloes

Dutton

Macciò

Dekel³

et al. 2016

Mon. Not. R. Astron. Soc.

101

118

View full text Add to dashboard Cite

We use ∼ 100 cosmological galaxy formation 'zoom-in' simulations using the smoothed particle hydrodynamics code gasoline to study the effect of baryonic processes on the mass profiles of cold dark matter haloes. The haloes in our study range from dwarf (M 200 ∼ 10 10 M ⊙ ) to Milky Way (M 200 ∼ 10 12 M ⊙ ) masses. Our simulations exhibit a wide range of halo responses, primarily varying with mass, from expansion to contraction, with up to factor ∼ 10 changes in the enclosed dark matter mass at 1 per cent of the virial radius. Confirming previous studies, the halo response is correlated with the integrated efficiency of star formation:In addition, we report a new correlation with the compactness of the stellar system: ǫ R ≡ r 1/2 /R 200 . We provide an analytic formula depending on ǫ SF and ǫ R for the response of cold dark matter haloes to baryonic processes. An observationally testable prediction is that, at fixed mass, larger galaxies experience more halo expansion, while the smaller galaxies more halo contraction. This diversity of dark halo response is captured by a toy model consisting of cycles of adiabatic inflow (causing contraction) and impulsive gas outflow (causing expansion). For net outflow, or equal inflow and outflow fractions, f , the overall effect is expansion, with more expansion with larger f . For net inflow, contraction occurs for small f (large radii), while expansion occurs for large f (small radii), recovering the phenomenology seen in our simulations. These regularities in the galaxy formation process provide a step towards a fully predictive model for the structure of cold dark matter haloes.

show abstract

“…It remains debatable whether the present‐day cores are innate, or whether a violent, primordial form of baryonic ‘feedback’ somehow conspired to erase (or exacerbate) all cusps (e.g. Blumenthal et al 1986; Gnedin & Zhao 2002; Gnedin et al 2004; Romano‐Díaz et al 2008; Jardel & Sellwood 2009).…”

Section: Introductionmentioning

confidence: 99%

Polytropic dark haloes of elliptical galaxies

Saxton

Ferreras

2010

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The kinematics of stars and planetary nebulae in early‐type galaxies provide vital clues to the enigmatic physics of their dark matter haloes. We fit published data for 14 such galaxies using a spherical, self‐gravitating model with two components: (i) a Sérsic stellar profile fixed according to photometric parameters, and (ii) a polytropic dark matter halo that conforms consistently to the shared gravitational potential. The polytropic equation of state can describe extended theories of dark matter involving self‐interaction, non‐extensive thermostatistics or boson condensation (in a classical limit). In such models, the flat‐cored mass profiles widely observed in disc galaxies are due to innate dark physics, regardless of any baryonic agitation. One of the natural parameters of this scenario is the number of effective thermal degrees of freedom of dark matter (Fd) which is proportional to the dark heat capacity. By default, we assume a cosmic ratio of baryonic and dark mass. Non‐Sérsic kinematic ideosyncrasies and possible non‐sphericity thwart fitting in some cases. In all 14 galaxies, the fit with a polytropic dark halo improves or at least gives similar fits to the velocity dispersion profile, compared to a stars‐only model. The good halo fits usually prefer Fd values from six to eight. This range complements the recently inferred limit of 7 < Fd < 10, derived from constraints on galaxy cluster core radii and black hole masses. However, a degeneracy remains: radial orbital anisotropy or a depleted dark mass fraction could shift our models' preference towards lower Fd; whereas a loss of baryons would favour higher Fd.

show abstract

Halo Density Reduction by Baryonic Settling?

Cited by 37 publications

References 45 publications

Density profile of dark matter haloes and galaxies in the horizon–agn simulation: the impact of AGN feedback

Density profile of dark matter haloes and galaxies in the horizon–agn simulation: the impact of AGN feedback

NIHAO IX: the role of gas inflows and outflows in driving the contraction and expansion of cold dark matter haloes

Polytropic dark haloes of elliptical galaxies

Contact Info

Product

Resources

About