Research
Here are descriptions of my first-author projects!
A uniform reanalysis of HST Exoplanet Atmsopheres --- A UV to IR Transmission Spectrum of WASP-69 b --- coming soon!
Binning is Sinning: The case of atmospheric retrievals and JWST/NIRSpec PRISM --- coming soon!
ACCESS: Transmission Spectrum of hot Saturn HATS-5 b
HATS-5 b is an interesting hot Saturn which has an equilibrium temperature of ~1025 K, which is a regime of predicted clear atmospheres at the pressures probed by transmission spectroscopy. As part of the ACCESS collaboration, we observed HATS-5 b over 5 nights with the IMACS instrument on the Magellan/Baade telescope. From these observations, we obtained the transmission spectrum and uncovered evidence of a clear, solar-metallicity, sub-solar C/O atmosphere with a tentative detection of water! We also see evidence for a depleted abundance for alkalis Na and K, which has been tentatively predicted around this temperature range. Future observations with JWST would be able to confirm this water detection as well as superbly constrain the atmospheric parameters.
Read the paper here (and see another great ACCESS paper I'm part of here).
The Formation of Earth's Largest Impact Crater
The Vredefort crater is Earth's largest verified impact crater. Though it is quite old (~2 billion years old) and thus has gone through extensive erosion, it was believed to originally have a diameter of 250-300 km. I used iSALE, a shock physics impact code, to simulate the impactor that created the crater. Our finding of an asteroid 20-25 km in diameter with an impact speed of 15-25 km/s was in disagreement with past simulation results, but is a better fit to the characteristics found in the crater. This impactor is even larger than the one that killed the dinosaurs, and would have caused similarly catastrophic effects globally, but only single-cellular life existed at the time. Additionally, using an ejecta layer found in Karelia, Russia, we were able to use the ejecta predictions from the simulations to constrain the landmasses of South Africa and Russia to have been ~2000 km apart 2 billion years ago - much further back than our current simulations can predict.
Star Formation and Stellar Outflows: Characterizing NGC 1333 and HH 7-11
NGC 1333 is likely the largest nearby star formation region (d~300 pc). As common in active star formation areas, contained within it are a number of Herbig Haro (HH) objects, tracing the stellar outflows of young stellar objects. HH 7-11 is a particularly striking and famous example, and is the subject of the study. I used Spitzer and Hubble Space Telescope observations to study these objects in detail, and using the MAPPINGS shock simulation program I determined the outflow characteristics of the HH 7-11 shock. Using this information, we estimated the total energy and momentum feedback from the outflow, which will eventually be done for all outflows in NGC 1333 in an attempt to determine the eventual fate of the natal cloud.