Strong gravitational lensing provides a natural magnifying effect for the study of the most distant galaxies. While there have been studies on the physical properties of star-forming clumps in strongly lensed galaxies, there is a critical need to automate the process of identifying these clusters, especially in scenarios where high flux density regions are to be discovered in large imaging surveys. Typical methods of clump identification rely on contrast enhancement through image smoothing and subtraction, followed by the use of visual and automatic source detection software. While generally effective, these approaches require careful parameter tuning and manual validation, limiting their efficiency and reproducibility. We present a novel software pipeline titled SUMAC (Software for Uniform Manifold Approximation of Clusters) that automatically processes FITS files of lensed galaxies, reduces the data using Uniform Manifold Approximation and Projection (UMAP), and outputs a topological map clustering together pixels with similar characteristics. Users can specify parameters of interest, including flux, spectral energy distribution, and morphology. We utilize JWST/NIRCam imagery of the z =2.481 lensed galaxy SGAS1110, confirming the functionality of SUMAC by automatically tagging points in the UMAP topological space, mapping them back to the imagery of the lensed galaxy to show alignment with visual star forming clusters. We additionally analyze spectroscopic data for the galaxy, ensuring pixels that SUMAC identifies as corresponding to star-forming clumps match characteristics such as age, metallicity, and emission line ratios that are indicative of star formation. SUMAC’s ability to handle large datasets efficiently, without requiring manual validation or extensive parameter tuning, ensures a more reproducible and scalable approach to high-redshift galactic analysis. SUMAC has the potential to be a valuable tool in the field of astronomical image processing, increasing the efficiency and accuracy of galactic dynamics studies.

Including updated thermodynamic ice polymorph properties in our planetary structure model predicts that TRAPPIST-1 h can support a subsurface liquid water layer with conduction present. TRAPPIST-1 h is of interest as it may be an ocean world with an icy surface based on observed mass, radius, and instellation. Previous research has created interior models that mathematically derive equations of state (EOS) for ice phases II through VI using ad-hoc parametrizations for density and heat capacity from various sources, which may not be applicable over such a large span of conditions. Notably these previous models predicted no liquid oceans nor ice VII within the hydrosphere. The surface pressure, mass of water, core radius, and metal-silicate core density of planet h remain unknown, leaving the question of how the hydrosphere changes when altering these parameters to reflect past and present ocean worlds. We present new predictions on the structure of TRAPPIST-1 h’s hydrosphere using, for the first time, accurate and self-consistent temperature- and pressure-dependent thermodynamic properties of water and ice polymorphs from the SeaFreeze framework to model the hydrosphere. Specifically, we compute different hydrosphere structures by iterating over a range of iron core fractions (0.05 - 0.9), and comparing models with and without a conductive layer at the top of the ice Ih crust. Results include a series of plausible hydrosphere structures that are consistent with the latest total mass and radius observations from Spitzer data of planet h. These outcomes can help interpret future spectroscopic and photometric observations.

Previous studies have established that galaxy shape and structure, otherwise known as morphology, correlate with environmental density: elliptical galaxies are more prevalent in high-density regions, and spiral galaxies are more prevalent in low-density environments. However, recent studies suggest that stellar mass may primarily drive this trend. In this work, we analyze around 3 million galaxies observed by the Hyper Suprime-Cam survey to reassess the correlation of morphology with large-scale environmental density from a quantitative perspective. The morphological measurements for our galaxies were done using the Bayesian machine learning framework Galaxy Morphology Posterior Estimation Network (GaMPEN). Our analysis employs a Monte Carlo-based framework to account for uncertainties in structural parameter measurements while investigating the correlation between bulge-to-total light ratio, the proportion of light emitted from the center of a galaxy, and environmental density. Leveraging the statistical power of our large dataset, we conclusively demonstrate that the morphology-environment correlation disappears when controlling for stellar mass. Thus, the observed trend arises predominantly because denser environments preferentially host more massive galaxies, making stellar mass the key driver of the morphology-environment relationship. Our results mark a significant advance in addressing this long-standing debate. Furthermore, the methodological framework presented provides a versatile tool for probing the interplay between galaxy properties and the large-scale structure of the universe, which will be particularly valuable in light of ongoing and forthcoming large surveys that supply high-resolution data needed to examine this relationship across extensive cosmic volumes.

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.

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.

The circumgalactic medium (CGM) consists of diffuse gas surrounding galaxies out to distances of roughly 300 kpc, forming an interface between a galaxy's interstellar medium (ISM) and the intergalactic medium. Researching the CGM's properties, including its metallicity and dynamics, provides crucial information about galaxy evolution and the fuel available for star formation. In this work, we study Complex C, a well-studied high-velocity cloud in the Milky Way's halo, to understand how its metal content varies on small spatial scales. Using 21-cm HI emission data in an Aitoff projection of the all-sky survey H14PI, we identify the spatial extent of Complex C. Assuming a distance of 3 kpc to the cloud, we then identify blue horizontal branch (BHB) stars from the Sloan Digital Sky Survey (SDSS) that lie behind it. These stars serve as bright background sources, allowing us to probe absorption from ionized calcium in Complex C along different sightlines. The cloud's distinct velocity offset from the Milky Way's ISM allows us to separate absorption features associated with Complex C from those arising in the ISM. By stacking spectra of multiple BHB stars, we can better isolate the absorption signature of Complex C in Ca-II and study how its calcium content varies across different regions of the cloud.