Aperture is a Particle-in-Cell (PIC) simulation code. The name is a recursive acronym: Aperture simulates Particles, Electrodynamics, and Radiative Transfer at Ultra-Relativistic Energies. It utilizes CUDA and runs on Nvidia GPUs, scaling well up to thousands of GPUs on the most powerful GPU-based supercomputer Summit. It has been used to study the magnetosphere of pulsars, magnetars, and black holes.

Pulsar Magnetospheres

I'm extremely interested in the physics of compact Astrophysical objects, including neutron stars and black holes. I have studied extensively the magnetospheres of pulsars, which are rapidly rotating neutron stars.

Recently the NICER team produced the most detailed map of hot spots on the surface of the pulsar PSR J0030+0451, and we used this information to infer its magnetic field configuration and obtained its multi-wavelength light curves that agree well with observations.

The left picture shows the magnetic field configuration of PSR J0030+0451. Closed magnetic field lines are drawn in green, and open field lines in light blue. Its current sheet is shown in volume rendering.

Interactive Visualization

I work on visualizations of 3D datasets using the framework THREE.js. Modern browsers can directly talk to the GPU, and can render 3D scenes very responsively. My visualizations works on PC, any mobile device, and are only one click away from experiencing them in VR.

The picture to the right is a Force-Free simulation of the magnetosphere of a rotating black hole done by my wife Yajie Yuan. Magnetic field lines are plotted and are color-coded by their initial azimuthal angle.