About me

Welcome! I am a postdoctoral fellow at the Canadian Institute for Theoretical Astrophysics (CITA). As a theoretical astrophysicist with a background in applied mathematics and fluid dynamics, I use analytical and computational tools to tackle a wide variety of problems.

My research program revolves in particular around the dynamics of rapidly rotating astrophysical flows. This focus has led me to work on astrophysical systems ranging from magnetized accretion flows around black holes, to our own Jupiter and Saturn, to rapidly spinning and tidally interacting stars.

Seismology

Seismology provides an important window into the deep internal structures of both stars and gaseous planets, which remain mysterious even in our own solar system. My research in seismology focuses on the impacts of rapid and differential rotation on the "normal mode" oscillations (global-scale vibrations) of planets and stars. Rotation modifies stellar and planetary vibrations through the Coriolis force, and by flattening equilibrium structures that would otherwise be spherically symmetric. This animation shows progressively stronger centrifugal flattening of a star with increasingly rapid rotation:

Saturn ring seismology

Saturn and Jupiter provide exciting testbeds for theories of rapidly rotating planets, spinning at 40% and 30% of the rates at which they would fly apart due to centrifugal forces (respectively). On top of that, Saturn's rings act as an effective seismograph, recording the torques produced by the planet's most gravitationally influential oscillation modes as propagating waves that we can use to very precisely measure the frequencies of Saturn's oscillations:

I performed the first calculations of Saturn's oscillation modes to completely account for the planet's rapid bulk rotation, realistic internal structure, and deep surface winds. My work in Saturn ring seismology laid theoretical groundwork that my collaborators and I used to infer Saturn's deep spin rate and differential rotation profile.

Tidal interactions

Just as the moon raises tides in Earth's oceans, mutual gravitation produces tidal bulges in stars, planets, and compact objects that orbit closely to one another. This animation shows a tidal bulge produced in a rotating gaseous planet by the gravitational potential of an orbiting point mass:

I characterized the shape of tidal bulges raised in planets and stars that are already centrifugally flattened by rotation. I also quantified the effect that tidal driving of internal waves can have on the shape of the bulge raised in Jupiter by its moon Io. This cutout animation illustrates internal tidal wave driving:

My ongoing work in tides focuses on the influences that the tidal dissipation of energy can have on orbital motion over time.

Accretion disks

Accretion disks serve as sites of planet formation, fuel the growth of stars and compact objects, and power some of the most energetic emission observed. My research in accretion disks focuses on the rich variety of wavelike and turbulent phenomena that manifest in magnetohydrodynamic (MHD) accretion disks that are eccentric, with elliptical (rather than circular) streamlines.

Magnetized, eccentric disks

My current work in accretion disks focuses on the ways that eccentric disk distortions can interact with and affect magnetic fields. This video shows the precession of a 2D model of a steady state disk that is both strongly eccentric and threaded by a vertical magnetic field:

Variability in X-ray binaries

During my PhD, I studied wave excitation and propagation in accretion flows around black holes. I characterized a family of MHD waves that may explain rapid variability occasionally observed in binary systems with a black hole accreting from a companion star. If this variability can be robustly tied to a physical mechanism, it would offer a unique test of general relativity.

This video shows vertical cross-sections through a cylindrical disk, and illustrates the excitation of radially trapped waves by a background eccentric distortion (obscured by an azimuthal average in this case) in a hydrodynamic black hole accretion flow:

I showed that such wave excitation can also take place in magnetized accretion disks that are affected by MHD turbulence.

Outreach

Here are a few talks and posters that I have presented both at conferences and publicly.

Talks

Posters

Contact