I'm an astrophysics grad student at Berkeley, working on the intersection of the intergalactic medium, cosmology, and supercomputing.


My research

I work on the Lyman-α Forest, an observational probe of the intergalactic medium. When we look at spectra of bright, distant objects called quasars, we a "forest" of absorption features blueward of the quasar's Lyα emission (the hump at 1200 Å). The absorption is the signature of the diffuse, ionized gas between us and the quasar.

Quasar spectrum
A high-resolution spectrum of a quasar (7-hour Keck HIRES exposure, data from Mike Rauch, figure from William Keel). You can see the quasar Lyα emission centered at 1216 Å, the Lyβ emission centered at 1026 Å and the absorption features making up the "forest" between.

I use cosmological hydrodynamic simulations to make predictions of Lyα forest flux statistics. Using many simulations with slightly varied IGM parameters and cosmological parameters, we can compare to observations to see which scenario matches best.

Lyman-alpha illustration
An illustration of the Lyα forest in a z = 2.6 quasar using our simulations. The background here is the HI density field from a Nyx simulation, which shows the evolution of the transmission through the IGM. The spectrum is also computed from the simulation, so the amount of blending and broadening is as realistic as possible. The quasar continuum is the Vanden Berk et al. 2001 composite.