ANGST: ACS Nearby Galaxy Survey Treasury

ANGST Website
Press Release
ANGST Data

With the Hubble Space Telescope, we can resolve individual stars in nearby galaxies. For my thesis, I am using these stellar populations to study the star formation histories of spiral galaxies. Some of my current projects:

• We can derive the star formation history of different regions of a galaxy by comparing the color-magnitude diagrams of resolved stellar populations with stellar evolution models. Using these star formation histories, we can track the change in stellar population with radius at different ages and compare our results with N-body simulations of disk galaxies.

• The star formation rate in external galaxies is often extrapolated from ultraviolet, Hα, and/or far-infrared emission using spectral synthesis models and an assumed initial mass function. We can calibrate these star formation rate indicators by connecting them with resolved stellar populations.

EDisCS: the ESO Distant Cluster Survey

EDisCS Website

I am using EDisCS to study the size-luminosity relation in disk galaxies. How does the average surface brightness of disk galaxies change over time? We can determine this by looking at a succession of ever more distant galaxy clusters, which we are seeing at ever younger ages. (However, we must be careful that the effects we observe are not a result of only being able to detect the brightest galaxies.) Does a galaxy's environment affect its surface brightness? We can compare galaxies in clusters and the field and look for differences in the size-luminosity relation.

"The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful. If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living."

-- Henri Poincare