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Joel Leja

Center for Astrophysics
NSF Astronomy & Astrophysics Fellow


I study how galaxies self-assemble over the history of the Universe. My specialization is in interpreting images and spectra of galaxies. These observations are very difficult to interpret, as they are generated by a wide variety of complex physical processes: star formation, stellar evolution, accretion onto supermassive black holes, and the thermodynamics of cold and warm gas. I build models which incorporate all of these physical processes and custom-fit them to catalogs of hundreds of thousands of galaxies observed across cosmic time. From this, it is possible to infer how galaxies change and evolve with time.