Elliptical galaxy (Credit: NASA, ESA, and The Hubble Heritage Team)
I spend most of my time analyzing the spectra of passive evolving galaxies in the nearby Universe. We look at the stellar populations properties of these objects as witnesses of their formation histories. We measure ages, metallicities, abundance patterns, and even the shape of the sellar initial mass function, to understand how the Universe got to be what we see now.
Spiral galaxy (Credit: NASA, STScI, WikiSky)
Morphology is another powerfull tool to understand galaxy formation. Abrupt changes in the radial light distribution of spiral galaxies are common, but we have not yet a clear explanation. Understanding whether these breaks and truncations are related to radial migration of stars or are the angular momentum imprint of the early Universe is other of my battle fields.