Bio

I'm a graduate student in astronomy at UC Santa Cruz working with Professor Enrico Ramirez-Ruiz. Broadly, I'm interested in problems involving fluid dynamics! This webpage visualizes some of my current research. The full version of my personal website is available at ryarza.gitlab.io

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The following video shows a hydrodynamical simulation of an encounter between a star and a black hole. The left panel shows the star (small orange dot) orbiting around the black hole (white cross). The dashed line indicates the approximate orbit of the star. The right panel shows a slice in the x-y plane of the density of the star.

The following images show slices in the x-y plane of a variety of fluid properties shortly after periapsis (the point of closest approach in the orbit). The slider allows comparison of two different fluid properties.

Pressure perturbation Pressure perturbation
Density Density

Pressure perturbation Pressure perturbation
Kinetic energy Kinetic energy

Density Density
Kinetic energy Kinetic energy

By running simulations at different periapsis distances, we can compare our results with semianalytical predictions. After confirming that we can reproduce those results, we can go the other way and explore close encounters, which are nonlinear. The following plot shows the amount of energy transfer from the orbit into stellar oscillations as a function of periapsis distance. Semianalytical calculations are shown as dashed lines and simulation results as crosses. Clearly we have some work to do!

Energy deposition