Constraining variations in the stellar initial mass function with the Fornax3D Survey
thesisposted on 2022-03-29, 03:45 authored by Bronwyn Reichardt Chu
The stellar initial mass function (IMF) describes the distribution of stellar masses when a population of stars first forms. It is a particularly crucial property connecting many different phenomena within a galaxy. Defining the IMF of a galaxy is therefore critical for helping us to understand how galaxies evolve over cosmic time. However, defining the IMF has been the subject of vigorous debate over the past few decades. Recent evidence from early-type galaxies which appear to become more dwarf star rich as galactic mass increases supports a variable rather than universal IMF. With improvements in technology, the question of whether the IMF varies spatially within galaxies has also begun to be investigated, with no clear result as yet. This thesis presents preliminary results from the Fornax3Dsurvey using the MUSE integral field spectrograph. Two techniques for finding the IMF are compared here for the lenticular galaxy FCC167: full spectral fitting, and a more constrained approach focusing on a few key features. While the two methods agree reasonably well on radial variations for the age and abundance parameters in common, the derived IMF shape and its variation within the galaxy differ.