Cold Dark Matter Substructures in Early-Type Galaxy Halos

Abstract

We present initial results from the "Ponos" zoom-in numerical simulations of dark matter substructures in massive ellipticals. Two very highly resolved dark matter halos with $M_{\mathrm{vir}}=1.2\times 10^{13}$ $M_{\odot }$ and $M_{\mathrm{vir}}=6.5\times 10^{12}$ $M_{\odot }$ and different ("violent" vs. "quiescent") assembly histories have been simulated down to $z=0$ in a $\Lambda$CDM cosmology with a total of 921,651,914 and 408,377,544 particles, respectively. Within the virial radius, the total mass fraction in self-bound $M_{\mathrm{sub}}>10^6$ $M_{\odot }$ subhalos at the present epoch is 15% for the violent host and 16.5% for the quiescent one. At $z=0.7$, these fractions increase to 19 and 33%, respectively, as more recently accreted satellites are less prone to tidal destruction. In projection, the average fraction of surface mass density in substructure at a distance of $R/R_{\mathrm{vir}}=0.02$ ($\sim 5-10$ kpc) from the two halo centers ranges from 0.6% to $\gtrsim 2$%, significantly higher than measured in simulations of Milky Way-sized halos. The contribution of subhalos with $M_{\mathrm{sub}}<10^9$ $M_{\odot }$ to the projected mass fraction is between one fifth and one third of the total, with the smallest share found in the quiescent host. We assess the impact of baryonic effects via twin, lower-resolution hydrodynamical simulations that include metallicity-dependent gas cooling, star formation, and a delayed-radiative-cooling scheme for supernova feedback. Baryonic contraction produces a super-isothermal total density profile and increases the number of massive subhalos in the inner regions of the main host. The host density profiles and projected subhalo mass fractions appear to be broadly consistent with observations of gravitational lenses.

14 pages, 15 figures, accepted for publication in ApJ after minor revisions, note the new Fig. 2

References in corpus (12)

• Dark Matter Candidates from Particle Physics and Methods of Detection
• Star Formation and Feedback in Smoothed Particle Hydrodynamic Simulations--I. Isolated Galaxies
• Momentum Injection by Supernovae in the Interstellar Medium
• A Superbubble Feedback Model for Galaxy Simulations
• Inference of the Cold Dark Matter substructure mass function at z=0.2 using strong gravitational lenses
• How well can cold-dark-matter substructures account for the observed radio flux-ratio anomalies?
• Dark Matter Heating and Early Core Formation in Dwarf Galaxies
• High resolution imaging of the anomalous flux-ratio gravitational lens system CLASS B2045+265: Dark or luminous satellites?
• Small scatter and nearly-isothermal mass profiles to four half-light radii from two-dimensional stellar dynamics of early-type galaxies
• Orbital Decay of Supermassive Black Hole Binaries in Clumpy Multiphase Merger Remnants
• The Argo Simulation: II. The Early Build-up of the Hubble Sequence
• An optimum time-stepping scheme for N-body simulations

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