The early gaseous and stellar mass assembly of Milky Way-type galaxy haloes
- Autor(en)
- Gerhard Hensler
- Abstrakt
In cosmological simulations of Cold Dark Matter (CDM) structure formation a vast number of subhalos is expected around massive galaxies like the Milky Way (MW). These DM subhalos are filled with baryons, gas that forms stars very early as observed from the stellar populations in the MW satellite galaxies. Satellite galaxies evolve in the tidal field of their mature galaxy and suffer accretion to the major galaxy and their partly disruption. By this, their mass loss is expected to feed the galaxy halo with stars and gas.From the Via Lactea II simulations we select a massive DM halo with its satellite system which evolves in the simulations to a present-day MW-type galaxy. We follow its evolution from redshift 4.5 to 2.5, i.e. over almost 2 billion years of the most interesting epoch of mass assembly. A high mass resolution allows for even low-mass satellites down to 10^5 Msun, but limits their distance range to the innermost 240 satellites of the system only. The applied chemo-dynamical method includes star formation, stellar energetic and chemical feedback, and gas physical processes.After the onset of the simulation our models demonstrate the action of tidal effects and satellite merging on the star-formation rate of the satellites, their gas loss by means of hot-gas expansion, of ram-pressure and tidal stripping, and the tidal extraction of stars, leading to the formation of the stellar and gaseous galactic halo. We also analyze the evolution of the satellites’ mass function, their baryonic and DM mass distributions, chemical abundances, their compactness, their present-day appearance, etc. with respect to observations and present-day correlations.
- Organisation(en)
- Institut für Astrophysik
- Journal
- IAU General Assembly Meeting
- Band
- 22
- Publikationsdatum
- 08-2015
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103004 Astrophysik
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/c0bbdbf4-efa3-47ba-8957-0700ed7b6156