On the Origin of Dwarf Elliptical Galaxies: The Fundamental Plane

Abstract

Early-type dwarf galaxies are the most common type of galaxies observed in the Universe. The origin of this kind of systems is still not well understood. The aim of this paper is to investigate whether the different locations of dwarf galaxies with respect to ellipticals in the face-on view of the fundamental plane could be due to the transformation of bright disc galaxies in low-mass systems by harassment. We have run high-resolution N-body numerical simulations to test the tidal stripping scenario of the dE galaxies. The present simulations modelled several individual tidal stripping events on initial disc-like galaxy models with different bulge-to-disc mass ratios. Tidal stripping is a very efficient mechanism for removing stars and dark matter particles from galaxies. The particles of the disc and halo components were easily stripped, while the bulge not. Thus, the scale length of the discs were 40-50% shorter than the initial ones. Prograde tidal interactions create tidal features like stable bars in the discs of the galaxies. After several tidal interactions the galaxy remnants looks like a dwarf spheroidal system. Simulated galaxies with initial large B/D ratios are closer to the face-on view of the fundamental plane defined by bright E and bulges of early-type galaxies. Nevertheless, galaxies with initial small B/D ratio are located, after four fast tidal encounters, at the position of dE galaxies in the face-on view of the fundamental plane. We conclude that fast galaxy-galaxy interactions are efficient mechanisms for transforming bright galaxies in dwarf ones. Indeed, the different location observed between Es and dEs in the face-on view of the fundamental plane can be explained by the formation of dwarf galaxies by harassment of late-type bright ones.

17 pages, 15 figures, accepted for publication at A&A Figures in higher resolution at [email protected]

References in corpus (13)

• The Importance of Mergers for the Origin of Intracluster Stars in Cosmological Simulations of Galaxy Clusters
• The origin of dwarf ellipticals in the Virgo cluster
• Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. III. Subpopulations: distributions, shapes, origins
• Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. I. On the possible disk nature of bright early-type dwarfs
• Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. II. Early-type dwarfs with central star formation
• The Metallicity Distribution of Intracluster Stars in Virgo
• Growth of galactic bulges by mergers. II. Low-density satellites
• The Kinematics of Intracluster Planetary Nebulae and the On-Going Subcluster Merger in the Coma Cluster Core
• Properties of the Dwarf Galaxy Population in Galaxy Clusters
• Internal kinematics of modelled interacting disc galaxies
• Bright and Dark Matter in Elliptical Galaxies: Mass and Velocity Distributions from Self-consistent Hydrodynamical Simulations
• Toward Understanding the origin of the Fundamental Plane for Early-Type Galaxies
• Clues on Regularity in the Structure and Kinematics of Elliptical Galaxies from Self-consistent Hydrodynamical Simulations: the Dynamical Fundamental Plane

Cited by in corpus (3)

• On the occurrence of galaxy harassment
• Frequency and properties of bars in cluster and field galaxies at intermediate redshifts
• Structures in the fundamental plane of early-type galaxies