Dissipationless collapse, weak homology and central cores of elliptical galaxies

Abstract

By means of high-resolution N-body simulations we revisited the dissipationless collapse scenario for galaxy formation. We considered both single-component collapses and collapses of a cold stellar distribution in a live dark matter halo. Single-component collapses lead to stellar systems whose projected profiles are fitted very well by the Sersic R^(1/m) law with 3.6 < m < 8. The stellar end-products of collapses in a dark matter halo are still well described by the R^(1/m) law, but with 1.9 < m < 12, where the lowest m values are obtained when the halo is dominant. In all the explored cases the profiles at small radii deviate from their global best-fit R^(1/m) model, being significantly flatter. The break-radius values are comparable with those measured in `core' elliptical galaxies, and are directly related to the coldness of the initial conditions. The dissipationless collapse of initially cold stellar distributions in pre-existing dark matter haloes may thus have a role in determining the observed weak homology of elliptical galaxies.

Accepted for publication in MNRAS (11 pages, 10 figures)

Cited by in corpus (23)

• The Structure & Dynamics of Massive Early-type Galaxies: On Homology, Isothermality and Isotropy inside one Effective Radius
• TDCOSMO IV: Hierarchical time-delay cosmography -- joint inference of the Hubble constant and galaxy density profiles
• The Carnegie-Irvine Galaxy Survey. III. The Three-Component Structure of Nearby Elliptical Galaxies
• The ACS Fornax Cluster Survey. II. The Central Brightness Profiles of Early-Type Galaxies: A Characteristic Radius on Nuclear Scales and the Transition from Central Luminosity Deficit to Excess
• The importance of dry and wet merging on the formation and evolution of elliptical galaxies
• The role of thermal evaporation in galaxy formation
• Bright and Dark Matter in Elliptical Galaxies: Mass and Velocity Distributions from Self-consistent Hydrodynamical Simulations
• The Evolutionary History of Galactic Bulges: Photometric and Spectroscopic Studies of Distant Spheroids in the GOODS Fields
• Two-component galaxies with flat rotation curve
• On the Origin of the Dichotomy of Early-Type Galaxies: The Role of Dry Mergers and AGN Feedback
• Mass distribution and orbital anisotropy of early-type galaxies: constraints from the Mass Plane
• Two-component Jaffe models with a central black hole. I: the spherical case
• N-body simulations for testing the stability of triaxial galaxies in MOND
• Gaussian random field power spectrum and the Sérsic law
• Dynamical masses of brightest cluster galaxies I: stellar velocity anisotropy and mass-to-light ratios
• Two-component galaxy models: the effect of density profile at large radii on the phase-space consistency
• Chandra Observations of Abell 2261 Brightest Cluster Galaxy, a Candidate Host to a Recoiling Black Hole
• Stellar velocity dispersion and initial mass function gradients in dissipationless galaxy mergers
• Symplectic coarse graining approach to the dynamics of spherical self-gravitating systems
• Structure of the equivalent Newtonian systems in MOND N-body simulations. Density profiles and the core-cusp problem
• Tidal mass loss in the Fornax dwarf spheroidal galaxy through N-body simulations with Gaia DR3-based orbits
• LeMMINGs. V. Nuclear activity and bulge properties: a detailed multi-component decomposition of $e$-MERLIN Palomar galaxies with $HST$
• A disturbance in the force. How force fluctuations hinder dynamical friction and induce core stalling