Current Research

  • convective burning shells in massive star

    Stellar Convection

    We are performing multi-dimensional models of stellar convection in advanced burning stages of stars using Castro. A key part of this is our accurate time-integration strategy for coupling hydro and reactions.

  • initial helium detonation in a double detonation Type Ia supernova simulation

    Double Detonation Type Ia Supernova

    We are exploring the sensitivity of the double detonation model for Type Ia supernova to the nuclear physics and coupling of the reactions to hydrodynamics.

  • volume rendering of a white dwarf merger

    White Dwarf Mergers

    We are modeling the inspiral of binary white dwarfs with the compressible Castro code to explore the double degenerate mechanism for Type Ia supernovae.

  • volume rendering of convection in an X-ray burst

    X-ray bursts

    We are exploring both the convection that precedes the runaway and the flame spreading across the neutron star in X-ray bursts.

  • image representing numerical simulations / algorithms

    Simulation Codes / Algorithms

    We develop the low Mach number hydrodynamics code MAESTROeX, the compressible simulation code Castro, and work on high performance computing and new time integration techniques for high fidelity simulations.

Previous Research

  • convection in a Chandrasekhar mass white dwarf

    White Dwarf Convection

    In the Chandra model for Type Ia supernova, reactions at the center of the white dwarf slowly heat the star, driving convection. Hot plumes buoyantly rise and cool via expansion. As the star continues to heat up, eventually a flame ignites. Understanding where the initial flames form is critical to understanding the subsequent explosion. We model the final stages of convection in a white dwarf, preceding the ignition.

  • a visualization of buoyant reacting bubbles

    Reacting Buoyant Bubbles

    When the first flames ignite in a Type Ia supernova, they buoyantly float upward as they burn outward. We have performed fully resolved studies of burning rising bubbles in both two and three dimensions in conditions appropriate to Type Ia supernovae to better understand these dynamics.

  • a volume rendering of convection in the helium layer on a Sub-Chandrasekhar mass white dwarf

    sub-Chandra SN Ia

    We are exploring the convective burning leading up to the ignition of a burning front in a helium layer on the surface of a white dwarf.

  • 3-d reactive Rayleigh-Taylor instability

    Reactive Rayleigh-Taylor

    The Rayleigh-Taylor instability plays a critical role in accelerating the burning front in Type Ia supernovae. We performed the first three-dimensional, direct numerical simulations of carbon flames in Type Ia supernovae undergoing the Rayleigh-Taylor instability and the transition to turbulence.

  • an image of a helium detonation on a neutron star surface

    Helium Detonations on Neutron Stars

    Two-dimensional calculations of the dynamics of the explosion from my thesis. We follow the detonation wave as it propagates 2 km across the surface of the neutron star.