The MAJORANA experiment and its follow-on, the Large Enriched Germanium Experiment for Neutrinoless Double-Beta Decay (LEGEND), search for the creation of matter in the form of neutrinoless double-beta decay, a process that would demonstrate that neutrinos are their own antiparticle and that lepton number conservation may be violated, allowing a deeper understanding of the matter-antimatter imbalance in the universe. MJ60 is a germanium detector used to investigate the low-energy region of the MAJORANA DEMONSTRATOR data, as well as the waveforms produced from incident betas in comparison with gamma events. The latter of these is important for understanding the background of LEGEND: the detectors are submerged in liquid argon, in which beta decays of argon-39 and argon-42 contribute to the background of the extremely sensitive experiment. MJ60 was originally a prototype for the P-type point-contact detectors used in the MAJORANA DEMONSTRATOR. Our group is using this detector to measure mechanisms of energy loss near the detector surfaces by recording events from the nearly monoenergetic beta emissions of metastable krypton-83 (83Kr) at 18 and ~30 keV. Analysis of the waveforms produced from these events, which has been my primary task, will allow us to investigate whether betas incident on our detectors’ passivated surface exhibit markedly different charge collection than gammas, as has been hypothesized. If this expectation is upheld, we will be able to produce a method to identify these events based upon a calculated parameter from the recorded waveforms. Such a parameter will help inform future detector R&D efforts, and will also contribute to background rejection capabilities in MAJORANA and LEGEND.

The COHERENT experiment is endeavoring to detect Coherent Elastic Neutrino-Nucleus Scattering (CEνNS) in several nuclear targets using the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). We search for very low energy (on the order of keV) coherent interactions between neutrinos and atomic nuclei using an array of particle detectors made of different scintillating materials. Neutrinos are fundamental particles under the Standard Model of particle physics that historically have not conformed to theoretical expectations. Understanding their interactions with other particles helps us potentially find other unexpected qualities of neutrinos and in that, discover new physics. At the UW component of the COHERENT team, I along with several other physics undergrads, have just finished characterizing over one-hundred NaI(Tl) crystals to contribute to a large array of detectors at ORNL where they will be illuminated by a strong, pulsed flux of neutrinos born from pions and muons generated in the SNS beam target. For each crystal, I used two characteristic radioactive sources (133Ba & 137Cs) to gather data on each crystal for characterization of their use at ORNL. Each crystal was run for 1.67 hours to find the optimal operating voltage (gain) and to explore the energy linearity of radiation detections at different points in each 7kg crystal (this allowed us to identify if the crystals had any cracks that would interfere with detections). In this talk, I intend to present the statistics on the measured crystal characteristics, including gains, energy resolution, scintillation uniformity as we prepare to ship the crystals to ORNL for installation in the array of other detectors capable of detecting the CEνNS phenomenon.

The increased development of space programs globally has led to increased funding for interplanetary sampling rovers, like MINERVA-II-2. However, in order for these autonomous space probes to reliably explore rough and unpredictable surfaces on other celestial bodies, they require more versatile and energy efficient robotics. Bio-inspired structures following the rigid origami design approach have the potential to be more compact, adaptable, and structurally efficient than conventional devices. The Leafout origami structure exhibits bistability, meaning that it can be configured in a stable-stored or stable-deployed shape without having an external power supply maintaining its configuration. Due to these unique features, the Leafout structure is capable of storing the potential energy generated from motions like jumping to repeatedly actuate with reduced energy inputs into the system. First, we corroborated dynamic simulation results with fabrications of cm-scaled prototypes composed of Bristol, PET, and Nylon as well as mm-scaled prototypes composed of Carbon-fiber-reinforced Polymers and Kapton. To emulate locomotion results from our Project Chrono physics engine simulations, we utilized frequency-based actuators attached to the Leafout's main crease lines to demonstrate repeated jumping motions. Attaching actively controlled small-scale servo motors allowed the Leafout structure to repeatedly jump in any direction on a 2-dimensional plane. Designing more structurally efficient systems in this manner may be the most practical solution to addressing both critical power and versatility limitations in autonomous space probes.

Since they were first discovered in the 1990’s, technological advances have led to a rapid growth in the study of exoplanets, which orbit stars outside of our solar system. Sodium was first detected in the atmosphere of an exoplanet in 2001 with transmission spectroscopy, and a limited but growing number of the 4100+ exoplanets which have been discovered to date have had their atmospheres probed with this technique. Despite the growing number, few studies exist with the aim of comparing the physical properties of different planets and atmospheric information. The goal of our research is to gather previously published data in order to characterize trends relating exoplanet physical properties to their atmospheric compositions. Our research has started with a focus on hot Jupiters: gas giant exoplanets which orbit very close to their host stars. We have expanded the parameter region of interest we are studying, and are working on streamlining the search so that results can be shared more easily with the community through the Habitable Zone Gallery website.

I have led a study of over 13 years of optical and near-ultraviolet spectropolarimetric observations of the famous Luminous Blue Variable (LBV), P Cygni. LBVs are a critical transitional phase in the lives of the most massive stars, and achieve the largest mass-loss rates of any group of stars. Using spectropolarimetry, I am able to learn about the geometry of the near circumstellar environment surrounding P Cygni and gain insights into LBV mass-loss. Using data from the HPOL and WUPPE spectropolarimeters, I have estimated the interstellar polarization contribution to P Cygni's spectropolarimetric signal, analyzed the variability of the polarization across the Hα emission line, searched for periodic signals in the data, and introduced a statistical method to search for preferred position angles in deviations from spherical symmetry which is novel to astronomy. 

Our research project aims to find red supergiant stars (RSGs) among the starburst galaxy IC10. Using stellar evolutionary theory, estimates can be made about how many RSGs are expected, based upon analyzation of known facts such as size, age, and metal content. The research conducted will allow for a comparison between observational data to theoretical expectations. RSGs are massive stars with a supergiant luminosity class; they are the coolest of the supergiants and have spectral types of K and M; hence temperatures below 4,100 K. Typically, they can be up to a thousand times the radius of the sun, and are therefore highly luminous. We began our search for these stars in IC10 by collecting the Two Micron All-Sky Survey and United Kingdom Infrared Telescope (UKIRT) J and K photometry. We then transformed the colors to luminosity and temperature allowing us to create an HR Diagram and identify candidate RSGs. Our next step was to continue to refine our results in order to remove foreground stars that aren't in the IC10 galaxy. We cross-matched our IC10 photometry with data from the GAIA satellite to obtain a list of proper motions and parallax values of all potential RSG candidates. From this we plotted the proper motion values vs. parallax to visually select stars in IC10. Our resulting list brings us closer to identifying RSGs in the starburst galaxy IC10.

The life and death of a galaxy is inextricably linked to the gaseous supply of its circumgalactic medium (CGM). Using the Hubble Space Telescope’s Cosmic Origins Spectrograph (HST/COS), we carry out quasar spectroscopy to probe this diffuse, extended gas. To characterize these galaxies, we supplement COS UV spectroscopy with optical spectroscopy from the Gemini North and South Telescopes. In total, 2,207 galaxy spectra were collected, all within 2.5 arcminutes of the quasar that have COS spectra. Of this initial group, 1,607 galaxies were classified as star-forming, elliptical, or some combination of the two based on the detected spectral lines. This study focuses on metal-line transitions in both galaxy and quasar spectra which track billions of years of supernova metal pollution. Absorption signatures from Ionized metals trace the physical conditions within the CGM of galaxies at the same redshift (+/- 500 km s-1) as the metal absorbers. We tie the metallicity of the CGM based on absorption-line measurements to the metal content of the host galaxies, as measured using strong emission lines. To date, no correlation exists between galactic metallicity and the metal content of the CGM. This finding indicates that the feedback processes within the CGM are complex and varied.