Isolated compact elliptical galaxies: Stellar systems that ran away

Abstract

Compact elliptical galaxies form a rare class of stellar system (~30 presently known) characterized by high stellar densities and small sizes and often harboring metal-rich stars. They were thought to form through tidal stripping of massive progenitors, until two isolated objects were discovered where massive galaxies performing the stripping could not be identified. By mining astronomical survey data, we have now found 195 compact elliptical galaxies in all types of environment. They all share similar dynamical and stellar population properties. Dynamical analysis for nonisolated galaxies demonstrates the feasibility of their ejection from host clusters and groups by three-body encounters, which is in agreement with numerical simulations. Hence, isolated compact elliptical and isolated quiescent dwarf galaxies are tidally stripped systems that ran away from their hosts.

Published in Science, 8 pages, 7 figures, 1 table including the supplementary information section; MS Excel table with the list of galaxies is available here http://www.sciencemag.org/content/suppl/2015/04/22/348.6233.418.DC1/aaa3344_Chilingarian_TableS1.xlsx

References in corpus (9)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The hierarchical formation of the brightest cluster galaxies
• The AIMSS Project I: Bridging the Star Cluster - Galaxy Divide
• Cosmic Ménage à Trois: The Origin of Satellite Galaxies On Extreme Orbits
• Evolution of dwarf early-type galaxies I. Spatially resolved stellar populations and internal kinematics of Virgo cluster dE/dS0 galaxies
• Kinematics and stellar populations of the dwarf elliptical galaxy IC 3653
• Kinematics and Stellar Populations of Low-Luminosity Early-Type Galaxies in the Abell 496 Cluster
• An isolated, compact early-type galaxy with a diffuse stellar component: merger origin?
• A Globular Cluster Toward M87 with a Radial Velocity < -1000 km/s: The First Hypervelocity Cluster

Cited by in corpus (11)

• Transient Double-beam Spectrograph for the 2.5-m Telescope of the Caucasus Mountain Observatory of SAI MSU
• RCSED - A Value-Added Reference Catalog of Spectral Energy Distributions of 800,299 Galaxies in 11 Ultraviolet, Optical, and Near-Infrared Bands: Morphologies, Colors, Ionized Gas and Stellar Populations Properties
• Implications for the origin of dwarf early-type galaxies: a detailed look at the isolated rotating dwarf early-type galaxy CG 611, with ramifications for the Fundamental Plane's (S_K)^2 kinematic scaling and the spin-ellipticity diagram
• Observational insights on the origin of giant low surface brightness galaxies
• $R_{\mathrm{e}}$. I. Understanding galaxy sizes, associated luminosity densities, and the artificial division of the early-type galaxy population
• On the formation mechanisms of compact elliptical galaxies
• A search for active galactic nuclei in low-mass compact galaxies
• Low-mass compact elliptical galaxies: spatially-resolved stellar populations and kinematics with the Keck Cosmic Web Imager
• M32 Analogs? A Population of Massive Ultra Compact Dwarf and Compact Elliptical Galaxies in intermediate redshift CLASH Clusters
• Compact elliptical galaxies hosting active galactic nuclei in isolated environment
• SDSS J122958.84+000138.0: A Compact, Optically red galaxy