Areas of Research
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Research
Nearby Galaxies
The infrared Andromeda galaxy M31 (NASA/JPL-Caltech/P. Barmby)
How do galaxies form their stars?
We see galaxies primarily by the light of stars formed in the past, but some nearby galaxies are still forming new stars while others have stopped - why?
One way to answer these questions is through observational studies of nearby galaxies. In these objects we can see the "big picture" --the global view of what happens in a galaxy, which is very difficult to determine for own our Milky Way.
Observing nearby galaxies as opposed to distant ones allows us to see fine detail and dissect galaxies into their component parts. In a kind of "galactic archaeology", we learn about the properties of galaxies at present, and use these to infer what the galaxies were like in the past.
Specific questions we are trying to address include understanding how the rate of new star formation changes with the properties of galaxies: their sizes, masses, and densities.
We also need to understand how to measure the star formation rate most accurately. Infrared observations of galaxies from NASA's Spitzer Space Telescope can be used to measure both galaxy mass and star formation rate through the light of old stars and the molecules and dust heated by young stars. With such data for a specially-selected set of galaxies we can begin to understand the relationship between star formation rate and other galaxy properties.
