Recent Research

Search for Satellite Galaxies with DES

Our Milky Way is surrounded by many small satellite galaxies. These galaxies are the most dark matter dominated and least chemically enriched systems known. Our understanding of these galaxies was greatly increased by the Sloan Digital Sky Survey (SDSS), which roughly doubled the known population of Milky Way satellites. However, the total number of satellite galaxies is still much smaller than predicted by simulations of cold dark matter. One factor in the disagreement between simulations and observations is that SDSS was located in the Northern Hemisphere and only observed a third of the sky. The new Dark Energy Survey (DES) is in the process of observing roughly 5000 square degrees of the Southern Hemisphere to unprecedented depth. My work focuses on searching for previously undiscovered satellite galaxies with DES. The results have been quite exciting!

As a member of the DES Collaboration, I am heavily involved in the data processing, specifically artifact masking and removal. Additionally, I help to lead the effort to validate the DES data for high-level science. In my spare time, I like to tinker with the DECam liquid nitrogen system. I've put together an introduction to DES computing and DES research at Fermilab here: "Getting Started with DES at Fermilab".

Past Research

Search for Dark Matter with the Fermi-LAT

My research seeks to better understand the dark matter that constitutes nearly 85% of the matter density of the Universe. Currently, I am searching for evidence of dark matter in gamma rays, using the Fermi Large Area Telescope (LAT). I am specifically interested in observations of nearby clumps of dark matter, such as the dwarf satellite galaxies of our own Milky Way. Dwarf galaxies are rich in dark matter but lack astrophysical gamma-ray production, making them prime candidates for dark matter detection. Additionally, numerical simulations predict that many more dwarf galaxies are yet undiscovered. Dark matter decay or annihilation in these galaxies would cause them to shine as unassociated gamma-ray sources.

As a member of the Fermi-LAT Collaboration, I enjoyed working to improve the LAT gamma-ray reconstruction software and increasing the performance of the instrument. I work on implementing multivariate classification algorithms into the LAT gamma-ray event selection. Much of the work that I do bridges the fields of particle physics and astrophysics.

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X-ray Astronomy and Observational Cosmology

The nature of dark energy, the mysterious component driving the accelerating expansion of the Universe, is one of the foremost questions in physics today. I sought to examine this question through the formation and growth of massive clusters of galaxies. These galaxy clusters are one of the most powerful probes of dark energy, since they are the largest gravitationally bound objects in the Universe and can be observed over cosmological times. The summer before graduate school, I was involved in a project which used observations from the Chandra and ROSAT X-ray telescopes to simultaneously constrain cosmology and the X-ray scaling relations of massive clusters. Additionally, this work was used to constrain the dark energy equation of state and set upper limits on neutrino mass.

The Advanced Pair Telescope (APT)

Gamma rays are produced by the most energetic phenomena in the Universe. At the lowest energies (<20 MeV), gamma rays are observed by Compton scattering telescopes, while at the highest energies (>100 GeV) they can be observed by ground-based Cherenkov telescopes. However, before the launch of the Fermi Large Area Telescope (LAT), the energy range between 100 MeV and 100 GeV was largely unexplored. While the LAT has unprecedented angular and energy resolution, its effective area is still quite small compared to ground-based arrays. Using Geant4, a software toolkit for high energy physics, I examined the potential for a large effective area space-based successor to the LAT. I developed simple and robust algorithms for reconstructing the incident direction of gamma rays and optimized the instrumental design subject to the constraints of a space-based mission.

Antibiotic Resistance

Infectious diseases are responsible for nearly one-third of all deaths worldwide. As an undergraduate research associate at the Public Health Research Institute, I investigated the transmission of infectious diseases in the New York City metropolitan area. I implemented multivariate clustering algorithms to map the spread of various genetic strains of Mycobacterium tuberculosis. These genetic maps were complimentary to spatial maps developed by hospitals and can help to identify the source and spreading mechanism of an outbreak. Additionally, I investigated the role of the virulence regulator gene in the human colonization of the Staphylococcus aureus bacterium. Staphylococcus aureus is one of the top five causes of hospital-contracted infections, and it is estimated that nearly 20% of the human population are long term carriers of Staphylococcus. Interestingly, we found that less virulent strains may be favored in infections, potentially due to the fact that they elicit a less severe host immune response.


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