I am an astrophysics PhD student at Caltech and alumnus of Rice University. I helped build a new low-frequency radio telescope at the Owens Valley Radio Observatory — the Owens Valley Long Wavelength Array. Sometimes it even works! I am a member of the Los Angeles Arboretum and I have fun playing soccer somewhat poorly. I wrote and maintain a couple officially registered packages for the Julia programming language.
The Owens Valley Long Wavelength Array (OVRO-LWA) is a low-frequency (roughly 30 to 85 MHz) radio telescope located at the Owens Valley Radio Observatory (OVRO) near Big Pine, California. Instead of a large mirror, the OVRO-LWA is composed of 288 antennas that work together coherently to detect radio waves arriving at Earth from the far reaches of the cosmos.
I helped build the OVRO-LWA as part of a team of scientists and engineers from Caltech, OVRO, JPL, and Harvard-Smithsonian. At times this involved assembling antennas, untangling (literally) miles of fiber optic cables in the desert, or even pulling fiber optic cables through conduit like an ox. However I also wrote a lot of software that helped make the instrument as successful as it is today.
I use the OVRO-LWA to study the distant universe, but it will also search for exoplanets, stellar flares, solar flares, and other exotic transients using its ability to capture snapshot images of the entire visible hemisphere.
Imagine putting the history of the universe on a calendar where January 1 corresponds to the big bang, and December 31 corresponds to the present day. The very first stars are thought to have begun emitting light around January 5. This period of time – known as the “cosmic dawn” – corresponds to when the universe was merely 5% of its current size.
Due to the finite speed of light, the light emitted from a star ten light-years away takes ten years to reach the Earth. Consequently we see this star today as it was ten years in the past. By searching for extremely stars and galaxies, astronomers can observe the universe as it was billions of years ago, and potentially allowing astronomers to directly study the cosmic dawn.
These stars and galaxies are firmly beyond the reach of the current generation of optical and infrared telescopes (for example, the Hubble Space Telescope). However a new suite of low-frequency radio telescopes are attempting to detect the diffuse hydrogen gas from this era using its characteristic 21 centimeter transition.
Unfortunately the cosmological signature of distant hydrogen gas is very faint, and it will be very difficult to separate this signal from the blinding light of our own Milky Way galaxy and other sources of radio emission. I used the Owens Valley Long Wavelength Array to construct a new map of the sky that will help astronomers find the cosmic dawn.