Popping star clusters as building blocks of the Milky Way Thick Disc

Abstract

It is widely believed that star clusters form with low star formation efficiencies. With the onset of stellar winds by massive stars or finally when the first super nova blows off, the residual gas is driven out of the embedded star cluster. Due to this fact a large amount, if not all, of the stars become unbound and disperse in the gravitational potential of the galaxy. In this context, Kroupa (2002) suggested a new mechanism for the emergence of thickened Galactic discs. Massive star clusters add kinematically hot components to the galactic field populations, building up in this way, the Galactic thick disc as well. In this work we perform, for the first time, numerical simulations to investigate this scenario for the formation of the galactic discs of the Milky Way. We find that a significant kinematically hot population of stars may be injected into the disk of a galaxy such that a thick disk emerges. For the MW the star clusters that formed the thick disk must have had masses of about 10^6 Msol.

10 pages, 6 figures, MNRAS, accepted

References in corpus (7)

• Rapid formation of exponential disks and bulges at high redshift from the dynamical evolution of clump cluster and chain galaxies
• The accretion origin of the Milky Way's stellar halo
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• Chemical similarities between Galactic bulge and local thick disk red giant stars
• Exploring the Local Milky Way: M Dwarfs as Tracers of Galactic Populations
• Galactic kinematics with RAVE data: I. The distribution of stars towards the Galactic poles
• Top-heavy integrated galactic stellar initial mass functions (IGIMFs) in starbursts

Cited by in corpus (15)

• On the fraction of star formation occurring in bound stellar clusters
• Thin disc, Thick Disc and Halo in a Simulated Galaxy
• Evolving Gravitationally Unstable Disks Over Cosmic Time: Implications For Thick Disk Formation
• The bound fraction of young star clusters
• Bimodality of [α/Fe]-[Fe/H] distributions is a natural outcome of dissipative collapse and disc growth in Milky Way-type galaxies
• Kinematical and chemical vertical structure of the Galactic thick disk I. Thick disk kinematics
• Comparing Young Massive Clusters and their Progenitor Clouds in the Milky Way
• Origin of the Local Group satellite planes
• Origin of the Metallicity Distribution in the Thick Disc
• A Dynamical Model for Clustered Star Formation in the Galactic Disk
• Ursa Major II - Reproducing the observed properties through tidal disruption
• Phase mixing due to the Galactic potential: steps in the position and velocity distributions of popped star clusters
• The Radial Distribution of Mono-Metallicity Populations in the Galactic Disk as Evidence for Two-Phase Disk Formation
• Turbulent gas-rich discs at high redshift: origin of thick stellar discs through 3D 'baryon sloshing'
• The Escape of Globular Clusters from the Satellite Dwarf Galaxies of the Milky Way