Protoplanetary Disks | Advisor: Ted Bergin

PhD Research: Using a combination of sophisticated modeling and observational data, Ilse Cleeves studies the chemical and physical properties of young circumstellar disks to understand what sets the stage for solar systems like our own to form. She’s interested in the disk’s chemistry, both in terms of how much water and organics might be available to a future planetary system, and also as a probe of physical conditions, such as the disk’s temperature and density. Most recently, she’s focused on the degree to which the gas in these disks has been ionized. In particular, she is exploring how much a star’s own X-rays ionize its disk, how much is from radioactive decay within the disk’s dust particles, and how much is contributed externally by cosmic rays. In terms of the latter, she has shown through modeling that young stars have the potential to shield their disks from cosmic-ray ionization by blowing out a heliosphere like the one in our own solar system. This is important because such protection limits turbulence in the disk, allowing material to stick together more easily and form planets, rather than breaking apart on impact. Her next step is to confirm these theoretical results with data from the Submillimeter Array and ALMA.

Why Michigan Astronomy?

Fertile Research Environment: “Michigan has one of the strongest star-formation departments in the U.S., with excellent professors and collaborators from around the world. There are always interesting new things to study. My advisor in particular has so many novel, creative ideas; I’ve gone in completely unexpected directions. I have several projects in the works – and a list of research ideas for the future.”