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:
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:
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.
