Enhanced Mass-to-Light Ratios in UCDs through Tidal Interaction with the Centre of the Host Galaxy
arXiv:astro-ph/0601330 · doi:10.1111/j.1365-2966.2006.10060.x
Abstract
A recent study of ultra-compact dwarf galaxies (UCDs) in the Virgo cluster revealed that some of them show faint envelopes and have measured mass-to-light ratios of 5 and larger, which can not be explained by simple population synthesis models. It is believed that this proves that some of the UCDs must possess a dark matter halo and may therefore be stripped nuclei of dwarf ellipticals rather than merged star cluster complexes. Using an efficient N-body method we investigate if a close passage of a UCD through the central region of the host galaxy is able to enhance the measured mass-to-light ratio by tidal forces leaving the satellite slightly out of virial equilibrium and thereby leading to an overestimation of its virial mass. We find this to be possible and discuss the general problem of measuring dynamical masses for objects that are probably interacting with their hosts.
accepted by MNRAS, 8 pages, 7 figures
Cited by in corpus (23)
- The Tidal Evolution of Local Group Dwarf Spheroidals
- From star clusters to dwarf galaxies: The properties of dynamically hot stellar systems
- The Nature of UCDs: Internal Dynamics from an Expanded Sample and Homogeneous Database
- Internal Properties of Ultra-Compact Dwarf Galaxies in the Virgo Cluster
- A top-heavy stellar initial mass function in starbursts as an explanation for the high mass-to-light ratios of ultra compact dwarf galaxies
- Dynamical masses of ultra-compact dwarf galaxies in Fornax
- Mapping the Dark Side with DEIMOS: Globular Clusters, X-ray Gas, and Dark Matter in the NGC 1407 Group
- Bright globular clusters in NGC 5128: the missing link between young massive clusters and evolved massive objects
- The formation of ultra-compact dwarf galaxies and nucleated dwarf galaxies
- The Next Generation Virgo Cluster Survey (NGVS). XIII. The Luminosity and Mass Function of Galaxies in the Core of the Virgo Cluster and the Contribution from Disrupted Satellites
- An extreme IMF as an explanation for high M/L ratios in UCDs? The CO index as a tracer of bottom heavy IMFs
- An Ultra Compact Dwarf around the Sombrero galaxy (M104): the Nearest Massive UCD
- Ultra-Compact Dwarfs in the Coma Cluster
- Spatially Resolved Kinematics of an Ultra-Compact Dwarf Galaxy
- Mass-loss and expansion of ultra compact dwarf galaxies through gas expulsion and stellar evolution for top-heavy stellar initial mass functions
- UCD Candidates in the Hydra Cluster
- How elevated is the dynamical-to-stellar mass ratio of the ultra-compact dwarf S999?
- Understanding the internal dynamics of elliptical galaxies without non-baryonic dark matter
- Steepened inner density profiles of group galaxies via interactions: An N-body analysis
- Efficiency of black hole formation via collisions in stellar systems: An analysis of data from simulations and observations
- Multi-phase environment of compact galactic nuclei: the role of the Nuclear Star Cluster
- Astrophysics in 2006
- Observational dynamics of low-mass stellar systems