About Me

I am a graduate student in astronomy at the California Institute of Technology. My interests lie primarily in radio astronomy, particularly the study of fast radio bursts (FRBs). I am currently leading the development and construction of a new instrument to search for FRBs in the local universe.

You can find my CV here and a list of publications here.

A map of possible locations for STARE stations. The OVRO and GDSCC stations are currently operational.

Fast Radio Bursts in the Local Universe

Fast Radio Bursts (FRBs) are millisecond bursts of GHz frequency radio emission of extragalactic origin. Only a few dozen have been seen and their origin is unknown. However, FRB 121102 repeats and shows that there are likely many more low luminosity FRBs than high luminosity FRBs.

Depending on how far this trend can be extrapolated, it may be reasonable to expect that objects in the Milky Way occasionally produce FRBs. These galactic FRBs would have flux densities in excess of 300 kJy. This is the idea behind the Survey for Transient Astronomical Radio Emission (STARE): to search for these low luminosity FRBs using an instrument with a gigantic field of view, but very low sensitivity.

STARE will consist of three stations located across the American southwest. With three stations, we will be able to effectively screen for local radio frequency interference (RFI) as well as localize signals to roughly 30 arcseconds. STARE's field of view sensitive to signals greater than 300 kJy is roughly π steradians.

We expect STARE to be fully operational by mid-2018.

Other Research

SN 2012ca: The First Type Ia-CSM SN in X-rays

Type Ia-CSM supernovae have similar spectra to Type Ia supernovae, but with superimposed narrow hydrogen lines from a surrounding circumstellar medium (CSM). I analyzed the data from the first type Ia-CSM supernova found in X-rays, a new probe of the CSM. I was able to infer that the CSM is likely asymmetric and similar to that around Type IIn supernovae.

The Eclipses of Terzan 5A

I looked at 10 years of data on Terzan 5A, a millisecond pulsar in a tight eclipsing binary system, to help determine the eclipse mechanism. Although I was unable to determine the eclipse mechanism, I did find a few clues: 1) The eclipse is longer if you only look at linearly polarized light. 2) The rotation measure varies significantly at the edges of the eclipse. 3) During observations with "mini-"eclipses (shown above), there is a small burst of linearly polarized light at the egress of the eclipse.

Using Black Widow Pulsars to Detect Gravitational Waves

Black widow pulsars are binary millisecond pulsars in tight orbits with small companions. Their orbits are highly variable, and in order to precisely time them so they can be used to detect gravitational waves, this orbital variability must be modeled out. However, since the same data are used to determine the timing parameters and search for gravitational waves, modeling more parameters opens the door to losing the gravitational wave signal. I was able to show that the orbital variability in black widow pulsars can be modeled without removing much of the gravitational wave signal, opening the door to using them to detect gravitational waves.

Gamma-ray Pulsar Emission Mechanisms

It is well known that the phase averaged spectrum of gamma-ray pulsars is harder than expected assuming the gamma-rays are produced from curvature radiation. This can be explained if the spectrum in each phase bin is different and has a shape consistent with curvature radiation, as the phase averaged spectrum is the sum of the spectrum in each phase bin and many different curvature radiation spectra add to give the observed hard phase averaged spectrum. However, I showed that in the Geminga and Vela pulsars, each phase bin also has a spectrum harder than expected from curvature radiation. This likely means there are multiple emission regions contributing to each pulse phase, or perhaps an unstable potential across one emission region.