Project HOLYDWARFS: The Star-formation histories and dark-matter content of faint dwarf elliptical galaxies

2011-06-15 – 2013-06-14

Abstract

In a cosmological context the dwarf galaxies (stellar masses M < 10^9 Msun) are crucially important because they hold keys to solve some of the most important questions in current extragalactic astronomy:
- What are the effects of the environment on the evolution of galaxies? Because of their low masses, dwarf are ideal targets to study environmental processes such as ram-pressure stripping and galaxy harassment.
- What are the mechanisms controling star formation? Due to their shallow gravitational potential wells, dwarf galaxies are very sensitive to processes like supernova feedback. This feedback heats and disperses the gas, affecting the star formation efficiency. In combination with environmental effects, it may even cause the gas to be lost from the host galaxy.
- What are the properties of the dark matter? Dwarf galaxies appear to be among the most dark matter dominated objects in the nearby universe, making them prime objects to study the properties and spatial distribution of this elusive ingredient of the universe.
-While the dwarf galaxies below 10^7 Msun appear to be dark matter dominated, those more massive than 10^9 Msun are not. Our goal is to investigate the terra incognita between these two regimes, i.e. galaxies with stellar masses around 10^8 solar masses. Trough stellar population, dynamical modeling and numerical simulations we will be able to shed light on the controlling mechanism of star formation and the role of the dark matter. We will study the dwarf dark-matter halo occupancy and investigate the physical processes that cause the photometric scaling relations to change slope around stellar mass m~10^8 solar masses.