Disruption of a Dwarf Galaxy Under Strong Shocking: The Origin of omega Centauri

Abstract

We perform N-body simulations of the dynamical evolution of a dwarf galaxy falling into the Milky Way galaxy in order to understand the formation scenario of the peculiar globular cluster $\omega$ Centauri. We use self-consistent models of the bulge and the disc of the Milky Way, as well as of the dwarf galaxy, and explore a range of dwarf models with different density distributions. Namely, we use King (1966) and Hernquist (1990) density profiles to model the density distribution in the dwarf. The central region of our King model has a density profile approximately $\propto r^{-2}$, while that of the Hernquist model is $\propto r^{-1}$. The difference in the dwarf's density distributions leads to distinct evolutionary scenarios. The King model dwarf loses its mass exponentially as a function of apocentric distance, with the mass-loss rate depending on the initial mass and size of the dwarf. Regardless of the initial mass and size, the King model dwarf remains more massive than $10^8$ \msun after a few Gyr of evolution. The Hernquist model dwarf experiences an accelerated mass loss, and the mass of the remnant falls below $10^8$ \msun within a few Gyr. By exploring an appropriate set of parameters, we find a Hernquist model that can attain the mass and orbital characteristics of $\omega$ Cen after a few Gyr.

arXiv comment12 pages, 14 figures, MNRAS in press

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Cited by in corpus (31)

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• Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo
• Two distinct halo populations in the solar neighborhood. III. Evidence from stellar ages and orbital parameters
• Radial distribution of the multiple stellar populations in omega Centauri
• The pure non-collisional Blue Straggler population in the giant stellar system omega Centauri
• Discovery of Ultra-Compact Dwarf Galaxies in the Virgo Cluster
• Space Velocities of Southern Globular Clusters. V. A Low Galactic Latitude Sample
• Exploring Halo Substructure with Giant Stars: Substructure in the Local Halo as Seen in the Grid Giant Star Survey Including Extended Tidal Debris from Omega Centauri
• The non-peculiar velocity dispersion profile of the stellar system omega Centauri
• The chemical evolution of Omega Centauri's progenitor system
• No evidence of mass segregation in the low mass Galactic globular cluster NGC 6101
• Formation of Omega Centauri by Tidal Stripping of a Dwarf Galaxy
• The dynamical state and blue straggler population of the globular cluster NGC 6266 (M62)
• The Complexity of the Cetus Stream Unveiled from the Fusion of STREAMFINDER and StarGO
• The Influence of Mass-Loss from a Star Cluster on its Dynamical Friction -- I. Clusters without Internal Evolution
• Modeling the chemical evolution of Omega Centauri using three-dimensional hydrodynamical simulations
• Searching for tidal tails around $\omega$ Centauri using RR Lyrae Stars
• Complex stellar populations in massive clusters: trapping stars of a dwarf-disc galaxy in a newborn stellar super-cluster
• A spectroscopic survey of EC4, an Extended Cluster in Andromeda's halo
• The GALAH Survey: Chemically tagging the Fimbulthul stream to the globular cluster $\omega$ Centauri
• RAVE stars tidally stripped/ejected from $\omega$ Centauri globular cluster
• A Survey of Proper Motion Stars. XVII. A Deficiency of Binary Stars on Retrograde Galactic Orbits and the Possibility that omega Centauri is Related to the Effect
• The Mass Function of omega Centauri down to 0.15 M_s
• Searching for merger debris in the Galactic halo: Chemodynamical evidence based on local blue HB stars
• On the origin of the gamma-ray emission from Omega Centauri: Milisecond pulsars and dark matter annihilation
• Abundance ties: Nephele and the globular cluster population accreted with $\omega$ Cen. Based on APOGEE DR17 and Gaia EDR3
• The Aquarius Co-Moving Group is Not a Disrupted Classical Globular Cluster
• Abundance analysis of a sample of evolved stars in the outskirts of Omega Centauri
• A Kinematically-Distinct RR-Lyrae Overdensity in the Inner Regions of the Milky Way
• The Nephele ecosystem: stars, globular clusters, and stellar streams associated with the progenitor galaxy of $\omega$ Centauri