Gravitational lensing is a naturally occurring phenomena in which foreground galaxies magnify the light of background galaxies, enabling observations that are otherwise too faint or distant to resolve. With the imaging capabilities of the James Webb Space Telescope (JWST), strongly lensed galaxies are now being spatially resolved to a degree previously unachievable. It is now not only possible but crucial to study lensed galaxies to completely unpack the properties and processes of galaxies in the early universe at these spatial scales. I use spectral energy distribution (SED) fitting and modeling tools on spatially resolved data from JWST. The data includes observations of COOLJ1241+2219, the brightest galaxy at Cosmic Dawn i.e., the first billion years of the Universe, and other high-redshift gravitationally lensed galaxies. These observations allow me to produce maps of key properties within the inner regions of these galaxies, revealing a diversity of star formation rates (SFR), star formation histories (SFH), and other stellar properties at the smallest spatial scales. This analysis is important for understanding how early galaxies evolved and quenched (stopped forming stars) not just as a single entity, but through distinct regions that otherwise cannot be resolved if not for magnification from gravitational lensing. This work is expected to significantly improve the methodologies employed to study galaxies as the sum of their individual parts, as we usher in a new era of larger telescopes in the next decade.

One significant unsolved problem in physics is the dominance of matter over antimatter in the universe.  The violation of Charge-Parity (CP) symmetry is one of the theorized conditions a physics process must satisfy to contribute to this imbalance.  So far, the observed CP violating processes are insufficient to fully explain the asymmetry.  Of the three categories of matter particles hadrons, charged leptons, and neutrinos, CP violation has been found in hadrons and is being investigated in neutrinos, but not in charged leptons.  We aim to probe this sector for CP violation by analyzing pairs of tau leptons, the heaviest charged leptons.  In this talk, I will describe the research I conducted in this area with the ATLAS detector at the Large Hadron Collider.  I present a sensitivity study which uses simulated proton-proton collisions to measure the spin correlations between the taus and compare them to predictions of the Standard Model of particle physics. We use the Large Hadron Collider’s large dataset of proton-proton collisions to improve on a 1997 measurement with the Large Electron-Positron collider.  Given the extremely short lifetime of the tau, it decays to other particles before being detected in ATLAS, forcing us to use the decay products to extract the relevant information.  We investigated multiple decay channels and devised a way to extract the CP violating spin correlation terms from the particle kinematics.  After obtaining values consistent with the Standard Model predictions in this new decay channel, I worked on statistical analysis to exploit dependencies on kinematic variables to reduce the uncertainty of the measurement.  Furthermore, I contributed to adapting the calculation to be more suitable for realistic detector simulation.  These efforts are in preparation for a future measurement with real ATLAS detector data.

Submarine channels represent the offshore continuation of onshore rivers. The shape of submarine channels captures valuable information about changes on the seafloor caused by fault movement during earthquakes. Many submarine channel systems are observed at the Cascadia subduction zone off the coast of Washington and Oregon. The Cascadia subduction zone is a tectonically dynamic system that exhibits many faults which appear to interact with these channels. These interactions are analyzed by quantifying the shape, or morphology, of the Astoria submarine channel, the offshore continuation of the Columbia River. We quantify channel morphology in ArcGIS Pro and Python in order to answer the hypotheses that 1) channels incise deeper where they cross active faults and 2) channel width is not affected by faulting. Some of these measurements include channel width, depth, width-depth ratios, bank slope, bank angle, cross swath profiles, and longitudinal profile analysis. This will offer insight into the behavior and evolution of faulting at the Cascadia subduction zone and how this affects people living along the Pacific Northwest coast who are at risk of earthquakes and tsunamis.

Multiepoch scintillation studies of pulsars shed light on the structure of the interstellar medium (ISM) by finding scattering screens that affect pulsar radio signals. PSR J0332+5434 has previously shown multiple scintillation arcs, indicating multiple scattering screens. My research analyzed new observations of PSR J0332+5434 to improve our understanding of its scintillation properties and determine the number and locations of its scattering screens along the line of sight (LOS). I analyzed over 30 high-cadence observations using the Green Bank Observatory’s 20m telescope using scintillation, secondary spectra with Scintools, and time-series Jupyter notebooks to generate dynamic spectra, secondary spectra, and time-series. My analysis revealed two scintillation arcs, indicating at least two scattering screens. When I combined these arcs with transverse velocity measurements, I detected a third scattering screen. Comparing my results to previous studies showed that two of the screens had been previously identified, but the third screen had not been identified. This means that PSR J0332+5434 may have at least five scattering screens: four previously identified and one new screen from this study. Furthermore, one of the arcs I observed is spread out and shows significant asymmetry. Only one arm is usually visible at a time, which shifts from left to right throughout my observations. This asymmetry could be caused by the variation in electron density in a region of the ISM along the LOS, causing the radio waves to refract. I plan to conduct more accurate observations using the Green Bank Telescope to investigate the refractive wedge causing this asymmetry and to identify any new scattering screens. Finding new scattering screens in the ISM—the interstellar gas clouds causing radio wave scintillation—allows us to develop better electron density models to improve pulsar distance measurements and improve our understanding of the Milky Way Galaxy’s structure.

Purpose: This study aimed to optimize the consultation strategy and timing of physicist consultation for proton prostate patients, thereby improving patient experience and resource utilization in radiation oncology department. Methods: 96 prostate patients undergoing proton therapy were surveyed after physics consult conducted at two time points: (1) prior to simulation or (2) prior to treatment. Survey responses were further divided into two groups—one responding at their first physics consult, the other responding at second consult. Anxiety levels were measured using the six-item short-form Spielberger State-Trait Anxiety Inventory (STAI). Anxiety scores were calculated and analyzed to compare first- versus second consult groups, as well as physics consults performed at different timing. Patient feedback on useful information during consultations was categorized using K-Means clustering into five themes. Results: Anxiety scores were comparable between first (28.60 ± 8.94) and second (29.75 ± 10.33) consultations (p = 0.59). Similarly, anxiety scores for consultations prior to simulation (30.59 ± 9.93) and prior to treatment (28.04 ± 8.83) showed no significant difference (p = 0.22). Patients identified five key information categories: (1) Radiation Types and Delivery, (2) Treatment Plan and Procedure Details, (3) Mechanism and Effects of Proton Radiation, (4) Proton Beam Generation and Therapy Pathway, and (5) Dosimetry and Risk. Conclusions: For proton prostate patients, a single physics consultation prior to treatment covering identified patient concerns maintains similar anxiety score comparable to two consultations model. Streamlining the consultation process in this manner can optimize medical physicist time without increasing patient anxiety level. This approach may serve as a framework for improving patient education and communication strategies of physics consult for proton therapy.

This project aims to enhance EEG source localization by addressing electrode misplacement, which can possibly lead to errors in brain activity reconstruction. We developed a optimization algorithm on the quasi-static electromagnetic model to optimize electrode positions. Using the multipole expansion method, our model minimizes discrepancies between recorded and predicted EEG signals. Our work has applicability to many clinical scenarios, like stroke activity localization, and can enhance existing brain activity reconstruction protocols.