Astronomy graduate student at the University of Washington
I'm a member of the UW Astronomy N-body shop working with Thomas Quinn to study simulations of planet formation. In particular, I'm interested in how this process plays out around M stars, which put out huge amounts of radiation during the pre main-sequence phase and are known to host extremely short period planets. When I'm not thinking about planet formation, I'm an avid hiker/backpacker and play bass for the band Night Lunch.
M stars have been the target of many recent exoplanet searches due to their abundance throughout the galaxy and also their strong planetary transit signals. The influx of recent exoplanet discoveries is causing us to rethink how the planet formation process works. In particular, M stars are extremely luminous during their pre-main sequence phase, which likely has a strong influence on both the thermodynamics and chemistry of the protoplanetary disk. The influence of stellar irradiation on early protoplanetary disks has not been well studied in the context of a fully 3D hydrodynamic treatment. This is something I am working to do with our N-body code ChaNGa.
In addition, I have also been using N-body simulations to look at planetesimal accretion at extremely short orbital periods. There have been a number of STIPs (systems of tightly-packed inner planets) discovered around M stars and whether these planets could have formed in situ or formed further out and then migrated inwards is still up for debate. In particular, planetesimal accretion has not been well studied outside of the context of the Solar System and a better understanding of this process at short orbital periods could help answer some of these questions.
Although planetesimal accretion in the Solar System has been the subject of many studies over the last few decades, there have been very few direct N-body simulations of this process due to the massive computational expense. Using our highly parallel N-body code ChaNGa, we recently ran the highest resolution N-body simulation of planetesimal accretion to date and showed that certain dynamical interactions between the embryos and planetesimals only turn are only effective if the distribution of planetesimals is sufficiently finely-grained.
Although our work was focused on examining planetesimal accretion in the vicinity of the Earth's orbit, we were able to produce a power-law break in the size distribution of planetesimals, which is reminiscent of the break seen in the size distribution of certain families of asteroid belt objects. We showed that this break is sensitive to the initial planetesimal size and could possibly be used to constrain planetesimal formation models.
Recent high-resolution images from ALMA have shown that protoplanetary disks can exhibit a rich variety of structure. One possible explanation for some of the ring-like structure seen in the dust emission from these disks are perturbations from nearby planets. In particular, mean motion resonances with unseen planets have been used to explain some of the banded structure seen in dusty disks such as HL Tau and TW Hya. The idea is that collisional grinding between planetesimals is responsible for a most of the dust emission. However, the influence of mean motion resonances on local planetesimal collision rates is not well understood. We have been using direct N-body simulations to study this problem and examine whether these resonances can create detectable changes in the dust emission of the disk.
In addition to research, I actively participated as a teacher and mentor for the UW Astronomy department. I have acted as a teaching assistant for our department's intro level astronomy classes numerous times and also act as a mentor for the pre-MAP program, which acts to introduce early undergraduates to astronomy research.
I also worked as an outreach specialist for Kitt Peak National Observatory in 2014 and 2015, in which I lead night time stargazing programs for the general public.