The evolution of dwarf galaxy satellites with different dark matter density profiles in the ErisMod simulations. I. The early infalls

Abstract

We present the first simulations of tidal stirring of dwarf galaxies in the Local Group carried out in a cosmological context. We use the ErisDARK simulation of a MW-sized galaxy to identify some of the most massive subhalos ($M_{vir}>10^8{M}_{\odot }$) that fall into the main host before $z=2$. Subhalos are replaced before infall with high-resolution models of dwarf galaxies comprising a faint stellar disk embedded in a dark matter halo. The set of models contains cuspy halos as well as halos with "cored" profiles (with asymptotic inner slope $\gamma =0.6$). The simulations are then run to $z=0$ with as many as 54 million particles and resolution as small as $\sim 4$ pc using the N-Body code ChaNGa. The stellar components of all satellites are significantly affected by tidal stirring, losing stellar mass and undergoing a morphological transformation towards a pressure supported spheroidal system. However, while some remnants with cuspy halos maintain significant rotational flattening and disk-like features, all the shallow halo models achieve $v/\sigma <0.5$ and round shapes typical of dSph satellites of the MW and M31. Mass loss is also enhanced in the latter, and remnants can reach luminosities and velocity dispersions as low as those of Ultra Faint Dwarfs (UFDs). We argue that cuspy progenitors must be the exception rather than the rule among satellites of the MW since all the MW and M31 satellites in the luminosity range of our remnants are dSphs, a result matched only in the simulation with "cored" models.

References in corpus (10)

• The unexpected diversity of dwarf galaxy rotation curves
• Rotation-Dependent Catastrophic Disruption of Gravitational Aggregates
• The Tidal Evolution of Local Group Dwarf Spheroidals
• Forged in FIRE: cusps, cores, and baryons in low-mass dwarf galaxies
• The rotation curves shapes of late-type dwarf galaxies
• Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. I. On the possible disk nature of bright early-type dwarfs
• Cosmic Reionization On Computers II. Reionization History and Its Back Reaction on Early Galaxies
• Mass modelling of dwarf spheroidal galaxies: the effect of unbound stars from tidal tails and the Milky Way
• The ACS LCID project. X. The Star Formation History of IC 1613: Revisiting the Over-Cooling Problem
• Reversal of Fortune: Increased Star Formation Efficiencies in the Early Histories of Dwarf Galaxies?

Cited by in corpus (18)

• Cold gas stripping in satellite galaxies: from pairs to clusters
• Contributions to the accreted stellar halo: an atlas of stellar deposition
• The Formation of Ultra-Diffuse Galaxies in Clusters
• Tidal stripping and the structure of dwarf galaxies in the Local Group
• The no-spin zone: rotation vs dispersion support in observed and simulated dwarf galaxies
• ELVES I: Structures of Dwarf Satellites of MW-like Galaxies; Morphology, Scaling Relations, and Intrinsic Shapes
• Systematically Measuring Ultra-Diffuse Galaxies (SMUDGes). V. The Complete SMUDGes Catalog and the Nature of Ultra-Diffuse Galaxies
• The phase-space structure of tidally stripped halos
• The Effects of Ram-pressure Stripping and Supernova Winds on the Tidal Stirring of Disky Dwarfs: Enhanced Transformation into Dwarf Spheroidals
• On the stability of tidal streams in action space
• On the early evolution of Local Group dwarf galaxy types: star formation and supernova feedback
• Tidal stirring of satellites with shallow density profiles prevents them from being too big to fail
• Tidal features of classical Milky Way satellites in a $\Lambda$CDM universe
• The ACS LCID Project XI. On the early time resolution of LG dwarf galaxy SFHs: Comparing the effects of reionization in models with observations
• Constraining the nature of dark matter with the star formation history of the faintest Local Group dwarf galaxy satellites
• Trial by FIRE: Probing the dark matter density profile of dwarf galaxies with GraphNPE
• Too small to succeed: the difficulty of sustaining star formation in low-mass haloes
• Constraining the shape of Milky Way satellites with distance gradients