Fornax Dwarf Spheroidal Galaxy - ESO/Digital Sky Survey 2

Galactic Chemical Evolution

Arguably the largest gap in our knowledge of stellar nucleosynthesis is the origin of elements heavier than iron—specifically those elements created by the rapid neutron-capture process (r-process). The chemical enrichment of galaxies—especially dwarf galaxies—helps distinguish between the proposed origins based on the continual build-up of r-process elements. I have measured the r-process element barium with Keck/DEIMOS medium-resolution spectroscopy. This work results in the largest sample of barium abundances (almost 300 stars) in dwarf galaxies ever assembled. By analyzing the chemical abundance trends, I have found that a large contribution of barium needs to occur at timescales similar to Type Ia supernovae in order to recreate our observed abundances, namely the flat or slightly rising trend of [Ba/Fe] vs. [Fe/H]. On going work using a galactic chemical evolution model concludes that neutron star mergers are the main contribution of r-process enrichment in dwarf galaxies.

Zwicky Transient Facility Camera Diagram - Caltech Optical Observatories

ZTF Instrumentation

The Zwicky Transient Facility (ZTF) is the next generation of the optical, time-domain survey iPTF and will be commissioned in 2017. ZTF has a 47 square degree field of view camera composed of sixteen 6144x6160 pixel CCDs. ZTF will attain a very precise flat focus plane by positioning the CCDs carefully in the lab, installing the camera on the Palomar 48-inch telescope, testing the CCD height and tilt to within 10 microns, and bringing the camera back to Caltech to perform a final adjustment following the tests recommendations. I have developed this test to accurately map each of the CCDs height and tilt, and have tested it on the current iPTF CCD array.

Tidal Disruption Event Simulation - Guillochon et al. 2014, ApJ, 783, 23

Tidal Disruption Events

As part of the intermediate Palomar Transient Factory (iPTF) collaboration I planned and executed iPTF observation runs on Keck and Palomar, in addition to updating the website used to keep track of all transients and follow-up observations (iPTF Marshal). You can see the Astronomer's telegraphs announcing new transient classifications based on spectroscopy here.

A paper is currently in preparation analyzing an extremely luminous, spectrally featureless tidal disruption event discovered with iPTF. Stay tuned!

Microwave Kinetic Inductance Detectors (MKIDs) - University of California, Santa Barbara

Previous Research


Ben Mazin's lab designs, tests and uses Microwave Kinetic Inductance Detectors (MKIDs). MKID arrays are composed of thousands individual LC resonators, where each resonator functions as an independent pixel and detects the arrival time and energy of every photon absorbed in its wavelength range. My research included both instrumentation and data analysis. I wrote programs to analyze and compare the functional properties of different versions of MKIDs. The quantum efficiency test bed and software I wrote accurately predicted the throughput of the ARCONS camera. I also aided in finding the eclipse times and calculating the period rate of change of SDSS J0926+3624 (an eclipsing AM CVn system).

Szypryt, P.; Duggan, G. E.; Mazin, B. A.; Meeker, S. R.; Strader, M. J.; van Eyken, J. C.; Marsden, D.; O'Brien, K.; Walter, A. B.; Ulbricht, G.; Prince, T. A.; Stoughton, C.; Bumble, B., "Direct detection of SDSS J0926+3624 orbital expansion with ARCONS", 2014, MNRAS, 439, 2765

Mazin, B. A.; Meeker, S. R.; Strader, M. J.; Szypryt, P.; Marsden, D.; van Eyken, J. C.; Duggan, G. E.; Walter, A. B.; Ulbricht, G.; Johnson, M.; Bumble, B.; O'Brien, K.; Stoughton, C., "ARCONS: A 2024 Pixel Optical through Near-IR Cryogenic Imaging Spectrophotometer", 2013, PASP, 125, 1348

Mechanics of Biopolymers

My first research experience was working with Omar Saleh in a biophysics laboratory using magnetic tweezers to investigate the dependence of the tensile response of charged copolymers (single-stranded DNA in this case) on the DNA sequence and salt concentration solution.

McIntosh, Dustin B.; Duggan, Gina; Gouil, Quentin; Saleh, Omar A., "Sequence-Dependent Elasticity and Electrostatics of Single-Stranded DNA: Signatures of Base-Stacking", 2014, Biophysical Journal, 106, 659