The chemical evolution of Dwarf Galaxies with galactic winds - the role of mass and gas distribution

Autor(en)

Gerhard Hensler, Simone Recchi

Abstrakt

Energetic feedback from Supernovae and stellar winds can drive galactic winds. Dwarf galaxies (DGs), due to their shallower potential wells, are assumed to be more vulnera-ble to these energetic processes. Metal loss through galactic winds is also commonly invoked to explain the low metal content of DGs.Our main aim in this presentation is to show that galactic mass cannot be the only pa-rameter determining the fraction of metals lost by a galaxy. In particular, the distribution of gas must play an equally important role. We perform 2-D chemo-dynamical simula-tions of galaxies characterized by different gas distributions, masses and gas fractions. The gas distribution can change the fraction of lost metals through galactic winds by up to one order of magnitude. In particular, disk-like galaxies tend to lose metals more easily than roundish ones. Consequently, also the final element abundances attained by models with the same mass but with different gas distributions can vary by up to one dex. Confirming previous studies, we also show that the fate of gas and freshly pro-duced metals strongly depends on the mass of the galaxy. Smaller galaxies (with shal-lower potential wells) more easily develop large-scale outflows; therefore, the fraction of lost metals tends to be higher.Another important issue is that the invoked mechanism to transform central cusps to cored dark-matter distributions by baryon loss due to strong galactic winds cannot work in general, must be critically tested, and should be clearly discernible by the chemical evolution of DGs.

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/d04a992f-9be1-4593-a194-aa09677bf5be