David C. Collins

 

Research

An incomplete summary of research topics I'm engaged in:

Molecular Clouds

All star formation occurs in molecular clouds. Molecular clouds are turbulent and magnetized.

The evolution magnetized turbulence is too complex to solve by hand, so we resort to simulations.

To do this, I added a divergence free (CT) MHD scheme to the adaptive mesh refinement (AMR) code Enzo. Enzo is free and open source, you can get it at enzo-project.org

Current and future work centers around running simulations and making fake observations. Observations of molecular clouds are quite complex, and magnetic fields are nearly impossible to measure, so we require simulations to properly understand the measurements.

Simulation of turbulence
Simulation of self-gravitating turbulence

Supernovae

Type Ia supernovae are essential for our understanding of distances in the universe. But everyone leaves out the magnetic fields! So we're doing that. See Hristov et al 2018 for more details, and a sweet movie that Boyan made to the right.

Several deflagration waves with magnetic field of different orientation (columns) and strength (rows). For strong enough fields, the instability is suppressed. For even stronger fields (top right corner), the field locks in structure, and the front speed increases.