Shape and kinematics of elliptical galaxies: evolution due to merging at z < 1.5

Abstract

Aims:In this study we investigate the evolution of shape and kinematics of elliptical galaxies in a cosmological framework. Methods: We use a set of hydrodynamic, self-consistent simulations operating in the context of a concordance cosmological model where relaxed elliptical-like objects (ELOs) were identified at redshifts z=0, z=0.5, z=1 and z=1.5. Results: The population of elliptical systems analysed here present a systematic change through time, i.e. evolution, by becoming rounder in general at z=0 and, at the same time more velocity dispersion supported. This is found to be primarily due to major dry mergers where only a modest amount of angular momentum is involved into the merger event. Despite the general trend, in a significant amount of cases the merger event involves a higher specific angular momentum, which in general causes the system to acquire a higher rotational support and/or a more oblate shape. These evolutionary patterns are still present when we study our systems in projection, mimicking real observations, and thus they should become apparent in future observations.

arXiv comment7 pages, 4 figures, re-submitted to A&A after positive referee report

References in corpus (36)

• Stellar Masses and Star Formation Histories for 10^5 Galaxies from the Sloan Digital Sky Survey
• The Aquarius Project: the subhalos of galactic halos
• The SAURON project -- IX. A kinematic classification for early-type galaxies
• The SAURON project -- X. The orbital anisotropy of elliptical and lenticular galaxies: revisiting the (V/sigma,epsilon) diagram with integral-field stellar kinematics
• Statistical Properties of Collisionless Equal- and Unequal-Mass Merger Remnants of Disk Galaxies
• Old Galaxies in the Young Universe
• Formation of early-type galaxies from cosmological initial conditions
• Kinematic Structure of Merger Remnants
• The Centers of Early-Type Galaxies with HST. V. New WFPC2 Photometry
• Galaxy mergers with various mass ratios: properties of remnants
• The Fundamental Scaling Relations of Elliptical Galaxies
• Properties of Early-Type, Dry Galaxy Mergers and the Origin of Massive Elliptical Galaxies
• Early and Rapid Merging as a Formation Mechanism of Massive Galaxies: Empirical Constraints
• The Importance of Dry and Mixed Mergers for Early-Type Galaxy Formation
• Initial conditions to cosmological N-body simulations, or how to run an ensemble of simulations
• Mergers and Mass Accretion Rates in Galaxy Assembly: The Millennium Simulation Compared to Observations of z~2 Galaxies
• Cold Dark Matter I: The Formation of Dark Halos
• Rotation and anisotropy of galaxies revisited
• The redshift evolution of early-type galaxies in COSMOS: Do massive early-type galaxies form by dry mergers?
• 2-Dimensional Kinematics of Simulated Disc Merger Remnants
• The Properties and Evolution of a K-band Selected Sample of Massive Galaxies at z~0.4 - 2 in the Palomar/DEEP2 Survey
• A Population of Massive and Evolved Galaxies at z$\ga$5
• Growth of galactic bulges by mergers. II. Low-density satellites
• The Impact of Box Size on the Properties of Dark Matter Haloes in Cosmological Simulations
• Elliptical galaxies from mergers of discs
• The X-ray emission properties and the dicothomy in the central stellar cusp shapes of early-type galaxies
• Conservation Laws in Smooth Particle Hydrodynamics: the DEVA Code
• Line-of-sight velocity distributions of elliptical galaxies from collisionless mergers
• Bright and Dark Matter in Elliptical Galaxies: Mass and Velocity Distributions from Self-consistent Hydrodynamical Simulations
• Encounters between spherical galaxies I: systems without dark halo
• Dynamical Models of Elliptical Galaxies in z=0.5 Clusters: I. Data-Model Comparison and Evolution of Galaxy Rotation
• The Surprising Anisotropy of Fast Rotating, Disky Elliptical Galaxies
• Intrinsic Axis Ratio Distribution of Early-type Galaxies From Sloan Digital Sky Survey
• Clues on Regularity in the Structure and Kinematics of Elliptical Galaxies from Self-consistent Hydrodynamical Simulations: the Dynamical Fundamental Plane
• On the Origin of the Dichotomy of Early-Type Galaxies: The Role of Dry Mergers and AGN Feedback
• Clues on the Physical Origin of the Fundamental Plane from Self-consistent Hydrodynamical Simulations

Cited by in corpus (15)

• The Sloan Lens ACS Survey. X. Stellar, Dynamical, and Total Mass Correlations of Massive Early-type Galaxies
• Connecting Angular Momentum and Galactic Dynamics: The complex Interplay between Spin, Mass, and Morphology
• Two-dimensional kinematics of SLACS lenses: III. Mass structure and dynamics of early-type lens galaxies beyond z ~ 0.1
• Orbital structure of merger remnants: Trends with gas fraction in 1:1 mergers
• The Dark Halo - Spheroid Conspiracy and the Origin of Elliptical Galaxies
• A review of elliptical and disc galaxy structure, and modern scaling laws
• A minor merger origin for stellar inner discs and rings in spiral galaxies
• The VIMOS VLT Deep Survey: the contribution of minor mergers to the growth of L_B >= L*_B galaxies since z ~ 1 from spectroscopically identified pairs
• Simulating multiple merger pathways to the central kinematics of early-type galaxies
• LEDA 074886: A remarkable rectangular-looking galaxy
• Spectro-photometric close pairs in GOODS-S: major and minor companions of intermediate-mass galaxies
• The assembly of spheroid-dominated galaxies in the EAGLE simulation
• Large-Scale Gas Dynamics in the Adhesion Model: Implications for the Two-Phase Massive Galaxy Formation Scenario
• Identifying supermassive black hole recoil in elliptical galaxies
• Lagrangian Volume Deformations around Simulated Galaxies