My Research

I am primarily interested in understanding the formation of the Solar System's planetesimals. To that end, I study the physical properties of the Outer Solar System’s small body populations. My efforts are mainly observational, and have involved Kuiper Belt search and discovery surveys to determine the belt’s size distribution and dynamical properties, compositional surveys (Col-OSSOS and H/WTSOSS) to constrain the belt’s formative origins, and focused studies to determine the mass and compositions of certain unique icy bodies. My recent research has found me performing numerical simulations, in which we model the formation of planetesimal singles and binaries through the gravitational collapse of a cloud of solids.

Some of these projects are highlighted below.

Planetesimal formation through collapse of a cloud of solids

In recent years, it has become evident that one plausible way to avoid the metre barrier is through gravitational collapse of a cloud of solids. This idea has become favourable because it appears that during the early stages of Solar System formation, when gas is still around in the protoplanetary disk, interaction between the gas and solids can cluster those solids together into a gravitationally bound cloud. Once the gas goes away, that cloud will then undergo collapse through gravity, forming large planetesimals along the way. Some pioneering work by David Nesvorny, who simulated this collapse directly, has shown that this process can produce binary planetesimal systems similar in mass and orbit to those binary systems we observe in the Kuiper Belt.

I have started a numerical simulation project with Ph.D. student James Robinson at Queen's University, Belfast. We have started where David left off, and wish to simulate the formation of these binary systems in more detail. We wish to explore the effects of various physical (eg. initial angular momentum distribution) and numerical aspects (eg. particle number, accretion model) have on the resulting systems.

While it is still early days for the project (Jamie only started in Sept 2016!) we already have some interesting first simulations. An example is shown below, which demonstrates the formation of a closely bound binary pair in ~100 years. What fun!

Reflectance Spectra of Kuiper Belt Objects

I am supervising Tom Secull as he plunks through his Ph.D. His project is building off a project I started in 2014 on gathering and interpreting reflectance spectra of Kuiper Belt objects and centaurs. Our aims are to identify materials on the surfaces of those objects. Tom is also now utilizing the excellent data we have acquired to search for surface variations driven by cometary activity of certain centaurs. The main tool we use is the XShooter Spectrograph on the Very Large Telescope in Chile. The spectra we have gathered are pretty spectacular, and have identified a few particular interesting targets for further study (likely with FORS2 and SINFONI spectrographs). Some of our spectra are shown below.

Note: in the above spectra, greyed-out regions are contaminated by telluric lines.