Astrophysics and Astronomy Commons^™

From Poetry To Policy: How H-Stem Has Guided My Research Path, Kayla D. Taylor

Student Works

Embry-Riddle PhD student Kayla Taylor was invited to share how Humanistic STEM has shaped her educational journey at the third annual Humanistic STEM symposium.

A Multispectral Analysis Of High Redshift Quasars And Their Energy Production Mechanisms, Erik Carlson

Open Access Dissertations

We present a complete sample of radio-loud (P_3.0 GHz = 10^27.26 W/Hz) high-redshift (z ≥ 2.5) quasars in the Northern Hemisphere (δ ≥ 0). Each source was imaged with a user-defined imaging protocol developed for the Very Large Array Sky Survey. Higher-resolution images were generated from archival observations and new Enhanced Very Large Array observations (Project Code: 24B-010).  We produced 407 images of galaxies, where we are likely the first humans to see them. Twenty of these sources were high-redshift jets which increased the number of known high-redshift jets by 69%. This sample represents one of the largest …

A Compact Frequency Comb Generator For Large-Format Superconducting Microwave Kinetic Inductance Detectors, Sungyoun Seo

Open Access Master's Theses

Microwave Kinetic Inductance Detectors (MKIDs) are promising superconducting detectors that achieve superior sensitivity to silicon-based photo detectors by leveraging a small bandgap of superconductors. They are advantageous for sensitive imaging instruments, particularly space telescopes. However, a large-format array with several hundreds of thousands of detectors is required for large-scale observations in space, and it encounters multiple challenges. The biggest challenge is the absence of compact, energy-efficient, and radiation-tolerant readout solutions. Of multiple functions in the MKID readout, the new frequency comb generator is presented in this thesis. It features a low on-chip memory requirement while promising the relaxed frequency resolution …

Hardware Implementation Of An Efficient Frequency Comb Generator For Microwave Kinetic Inductance Detectors, Frank Atobrah Danso

Open Access Master's Theses

The frequency comb generator is an essential component in the readout of superconducting detectors. This component is responsible for generating the resonant frequencies necessary to detect photon interaction with the detectors. This component however has not received the much needed attention in terms of readout systems optimization. Conventional implementations rely on either inverse fast Fourier transform (IFFT) engines, which scale poorly in power with increasing frequency resolution requirement but allow flexible tone updates, or lookup tables (LUTs), which demand large memory for high frequency resolution.

Microwave Kinetic Inductance Detectors (MKIDs) are superconducting detectors which have gained significant interest for cryogenic …

Stars, Statutes, And Sharing: Designing Global Ip Frameworks For Space-Based Discoveries, Ed Koellner

Marquette Intellectual Property & Innovation Law Review

As humanity stretches farther into space physically, commercially, and intellectually, contemporary legal frameworks are beginning to creak under the pressure. Intellectual property laws seem to be playing catch-up. Those laws were written for a world bound by borders and gravity, not for orbital labs, the Earth’s Moon, or AI-generated inventions drifting above the Earth.

This article takes a closer look at the increasingly complex intersection of space law, intellectual property, and artificial intelligence. This domain is no longer reserved for state-led missions or high-level treaties. Now and in the near future, a university lab or a private startup might be …

Clea Labs For Stellar And Cosmological Astronomy Bottled For Silicon Macintosh, Hansika Reddy Bandela, Yuktha Shetty, Jack C. Straton

Physics Faculty Publications and Presentations

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs were developed for Windows, but the authors have bottled them for Silicon Macintosh computers.

The Origin And Properties Of Ionized Gas In The Inner Milky Way Disk, Dylan J. Linville

Graduate Theses, Dissertations, and Problem Reports (ETD)

The interstellar medium (ISM) plays a crucial role in the evolution of the Milky Way and other spiral galaxies, but numerous gaps remain in our collective understanding of its properties. The now-complete Green Bank Telescope (GBT) Diffuse Ionized Gas Survey (GDIGS) and the ongoing extension, the GBT Diffuse Ionized Gas Survey at Low Frequencies (GDIGS-Low), offer the opportunity to study the ionized component of the ISM at unmatched sensitivity and resolution. In this dissertation I will utilize GDIGS and GDIGS-Low data to improve our understanding of discrete regions of ionized gas. I first use GDIGS to provide improved measurements of …

Three-Dimensional Spreading Of Magnetic Reconnection Between Non-Parallel Flux Ropes With A Guide Field, Regis John

Graduate Theses, Dissertations, and Problem Reports (ETD)

Magnetic reconnection is a fundamental plasma process that facilitates the rapid conversion of magnetic energy into particle acceleration, plasma flows, and heating. It plays a central role in explosive astrophysical events such as solar flares, where vast amounts of magnetic energy are released on short time scales. A key structure in many reconnection sites is the magnetic flux rope, a column of plasma carrying current threaded by helical magnetic fields, which is frequently involved in or generated by reconnection. Understanding how reconnection unfolds in such flux rope systems is critical for interpreting both space weather phenomena and laboratory plasma dynamics. …

Modeling Energetic Electron Precipitation: Radiation Belt Loss, Its Drivers, And Atmospheric Impacts, Zhi Gu Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

Energetic electrons in the terrestrial outer radiation belt present significant hazards to spacecraft systems and human operations in space. The intensity of these electrons can vary rapidly and dramatically during geomagnetic storms, governed by a complex competition between acceleration and loss processes. Among these, precipitation into the atmosphere via resonant wave-particle interaction acts as a key loss mechanism. This dissertation focuses on improving the quantification of energetic electron precipitation using physics-based modeling constrained by low-altitude satellite observations.

We begin by developing and validating the Drift-Diffusion model, which simulates low-altitude electron dynamics while accounting for azimuthal drift, pitch-angle diffusion, and atmospheric …

Modeling Relativistic Fluids In Dynamical Spacetimes, Terrence Alphonse Pierre Jacques

Graduate Theses, Dissertations, and Problem Reports (ETD)

Multi-messenger astrophysics opens a new era in our understanding of the most dynamic and energetic systems in the Universe. Correlating gravitational-wave and electromagnetic signals in space and time enables stringent tests of models for core-collapse supernovae, merging supermassive black-hole binaries with accretion disks and jets, and mergers of compact object binaries such as binary neutron stars (BNS) and white dwarfs. Comparisons between models and multi-messenger observations may be used to constrain the neutron-star equation of state (EOS), formation channels for compact-object binaries, and emission mechanisms behind short gamma-ray bursts.

In modeling such astrophysical systems, great success has been achieved by …

Rapid Inference Of Atmospheric Feature Parameters From Light Curves Using Bayesian Neural Networks, Eugenio A. Diaz

Honors Undergraduate Theses

Mapping atmospheres using rotationally modulated light curves offers insights into cloud structures and dynamics. Current retrieval methods, primarily based on Markov Chain Monte Carlo (MCMC) techniques like Aeolus, can infer atmospheric features but are computationally prohibitive for large datasets. This project proposes a neural network (NN) framework for the rapid, variational inference of atmospheric structure from light curves, particularly those of brown dwarfs. The primary approach focuses on training a Bayesian NN (BNN) to perform regression, predicting the spot parameters that describe the object's surface brightness map. Given the scarcity of suitable observational training data, the BNN is trained on …

Dual View Of The Z2-Gauged Xy Model In 3d, Piers Coleman, Anatoly Kuklov, Alexei Tsvelik

Publications and Research

The Z₂ gauged XY model is of long-standing interest both in the context of nematic order, and the study of fractionalization and superconductivity. This paper presents heuristic arguments that no deconfinement of the XY field occurs in this model and presents results of a large-scale Monte Carlo simulations on a cubic lattice which are consistent with this conclusion. The correlation radius determining the confinement is found to be growing rapidly as a function of the parameters in the phase featuring the nematic order. Thus, mesoscopic properties of the system can mimic deconfinement with high accuracy in some part of …

The Gaps Programme At Tng: Lxv. Precise Density Measurement Of Toi-1430 B, A Young Planet With An Evaporating Atmosphere, D. Nardiello, J. M. Akana Murphy, R. Spinelli, M. Baratella, S. Desidera, V. Nascimbeni, L. Malavolta, K. Biazzo, A. Maggio, Ryan J. Oelkers

Physics & Astronomy Faculty Publications

Context. Small-sized (< 4 R_⊕) exoplanets in tight orbits around young stars (10–1000 Myr) give us the opportunity to investigate the mechanisms that led to their formation, the evolution of their physical and orbital properties, and, in particular, their atmospheres. Thanks to the all-sky survey carried out by the TESS spacecraft, many of these exoplanets have been discovered, and have subsequently been characterized with dedicated follow-up observations.

Aims. In the context of a collaboration among the Global Architecture of Planetary Systems (GAPS) team, the TESS-Keck Survey (TKS) team, and the California Planet Search (CPS) team, we measured …

Uncertainty In Solar Wind Propagation: An Analysis Of L1 To Earth Variability And The Implications For Geospace Modeling In Space Weather Operations, Espen T. Fredrick

Physics Dissertations - Archive

As humanity's technological dependence grows, so does its vulnerability to space weather. Space weather describes solar-driven phenomena in the near-Earth space environment and their terrestrial effects. Many of these effects occur due to the interaction of the solar wind and Earth's magnetosphere. The solar wind originates at the solar corona and carries solar plasma and magnetic field outward through the solar system. This magnetic field, known as the interplanetary magnetic field (IMF) during transit, can undergo magnetic reconnection with Earth's geomagnetic field when oppositely aligned field lines converge. This process transfers energy into Earth's magnetosphere, driving space weather phenomena.

Space …

Characterizing The Earth's Magnetosheath With In Situ Measurements, Hector A. Salinas

Physics Dissertations - Archive

Earth’s magnetosheath is a region of shocked plasma that mediates energy and momentum transfer from the solar wind to the magnetosphere. The dynamics and thus the plasma structures of this region are highly dependent on upstream solar wind conditions. As such, the region is often characterized as a turbulent environment, with the most intense periods of turbulence occurring often under quasi-parallel bow shock conditions. This magnetosheath turbulence displays as variable and large-scale fluctuations with in-situ measurements. Given that turbulence is a characteristic feature of the magnetosheath, this dissertation asks two questions: (1) How are plasma structures inside the sheath affected …

On The Orbital Dynamics Of Exoplanets, Exomoons, And Submoons, Shaan Dharmesh Patel

Physics Dissertations - Archive

Although exoplanet detection has long been a central focus in astronomy, growing interest in exomoons has highlighted the increasing need for theoretical frameworks to interpret emerging candidates. Furthermore, while submoons, natural satellites orbiting moons, are not presently observed in the Solar System and remain speculative (e.g., the hypothesized past submoon of Saturn’s Iapetus), their existence is plausible within the context of the complex and diverse architectures now identified across planetary and stellar systems. We develop a generalized framework to assess the orbital stability of exomoons and submoons through comprehensive N-body simulations incorporating both three-body dynamics and tidal interactions, with the …

Archival Stellar Flare Follow-Up In Evryscope Observations, Tyler J. Thomas

Honors Undergraduate Theses

M dwarfs, the most abundant stars in the galaxy, are prime targets in the search for habitable exoplanets. However, their high flare activity may compromise planetary atmospheres, with Coronal Mass Ejections (CMEs) increasing this risk. Despite this, the relationship between M dwarf flares and CMEs is not well understood. This study uses archival data from Evryscope North and South, crossmatched with Sloan Digital Sky Survey (SDSS) and Gaia data, to investigate this relationship. This crossmatching demonstrated an abundance of stars within the 20 arcsecond Evryscope uncertainty. The analysis also revealed a modest excess of K1 and F9 type stars but …

Classification Of Variable Stars Using Convolutional Neural Network, Abhina Premachandran Bindu

Dissertations and Theses

This research focuses on developing Convolutional Neural Networks (CNNs), for the process of classifying and identifying variable stars through the analysis of unprocessed light curves from Transiting Exoplanet Survey Satellite (TESS). As astronomical data is becoming increasingly complex, and as advanced missions deploy sophisticated instruments for data collection, both the quality and quantity of the data are improving at a rapid pace. This has created an urgent need to automate the analysis process using efficient and effective methods, such as those based on machine learning. While previous research has explored machine learning approaches, there has been limited focus on implementing …

Clea Labs For Planetary, Stellar, And Cosmological Astronomy Configured For 64-Bit Windows 11+ Machines, Itan Altamirano, Jack C. Straton

Physics Faculty Publications and Presentations

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs were developed for 32-bit Windows machines but PSU student Itan Altamirano reconfigured installation programs to bypass steps that ask for DVDs and allowing these 32-bit programs to work on 64-bit Windows 11+ computers.

Evaluation Of The Stability Of Argan Oil Nanoemulsions Formulated And Optimized Through Experimental Design For Dermatological Applications, Yousra Mdarhri, Ikram Bouziane, Narjisse Mokhtari, Lama Rissouli, Ahmed Touhami, Fakhita Touhami, Mohamed Chabbi

Physics & Astronomy Faculty Publications

Argan oil is a highly sought-after natural product renowned for its therapeutic and rejuvenating properties. This study focused on harnessing its dermatological bioactivity by developing stable nanoemulsions through a simple low-energy method using a single non-ionic surfactant. The composition and properties of Argan oil were analyzed using High-Performance Liquid Chromatography (HPLC), Gas Chromatography (GC), and quality indexes, adhering to international standards. The effect of system composition on stability was evaluated using a pseudo-ternary phase diagram and Phase Inversion Composition (PIC) emulsification technique. Optimal process parameters for producing stable nanoemulsion were determined through Response Surface Methodology (RSM) analysis. The resulting nanoemulsions …

An Overview Of Emri Data Analysis, Zou Xiaobo, Soumya Mohanty, Xie Qunying, Chen Xian, Luo Honggang, Liu Yuxiao, Han Wenbiao, Jiao Jiageng, Zhang Xuehao, Zhao Shaodong

Physics & Astronomy Faculty Publications

The Extreme Mass-Ratio Inspiral (EMRI) refers to binary system with a mass ratio between 104 and 107, where the smaller object loses energy as it inspirals closer to a massive black hole, emitting gravitational waves. It is estimated that there are 105 cycles during the last year before plunge, providing rich information on the evolution of gravitational wave phases. The motion of the smaller object in the strong gravitational field of the massive black hole can reflect the surrounding spacetime structure. The massive black hole is typically located at the center of a galaxy, in which the galaxy environment leaves …

Precision Measurement Of The Muon’ S Anomalous Precession Frequency Using Energy Integrated Analysis In The Fermilab Muon G- 2 Experiment, Joseph Peck

Theses and Dissertations--Physics and Astronomy

This dissertation investigates the anomalous magnetic moment of the muon, aµ, through the Fermilab Muon g -2 Experiment, which aims to measure aµ to a precision of about 140 parts-per-billion.

Muons were injected into a magnetic storage ring where their decay positrons were detected by calorimeters. The changing spin and momentum orientation leads to an oscillation in decay positron counts, known as the anomalous precession frequency ! a. Using the magnetic field and !a measurements, we can determine the value of a µ. This study focuses on the Q-Method determination of !a, which utilizes an energyintegrated reconstruction rather than high-energy …

A Multidisciplinary Approach To The Thermal And Non-Thermal Mechanisms In Galaxy Clusters, Sheng-Chieh Lin

Theses and Dissertations--Physics and Astronomy

Galaxy clusters form at the intersections of the cosmic web and carry imprints of the structure formation history of the universe. As massive, multi-component systems, they offer unique insights into the astrophysical processes that govern both structure formation and galaxy evolution. Observable across the full electromagnetic spectrum, clusters emit photons through a variety of mechanisms, each tracing different physical processes. This dissertation investigates both the thermodynamic and non-thermal properties of the intracluster medium (ICM) to better understand the physical processes shaping observed phenomena. It comprises three main studies, each targeting a different aspect of galaxy cluster physics. In the second …

Pave Outer Space And Put Up A Parking Lot: Lagrange Points Should Be The Common Heritage Of Mankind, David A. Koplow

Michigan Journal of International Law

Outer space offers a vast array of opportunities, with different locations or regions available for exploitation by diverse users for a growing variety of satellite functions. But not all sectors of space are equally valuable for all applications, and the most desirable venues can become crowded, affording a premium for those who gain access first and impeding the development of a fair and efficient all-inclusive international legal regime.

This article focuses on Lagrange points, a finite series of special locations in space where the gravitational forces from a pair of large celestial bodies interact in unusual ways. These points afford …

Response Of Galactic Disks To Dark Matter Halo Triaxiality, Alex J. Hutton

College of Graduate Studies: Theses & Dissertations

In this study we examine the influence of dark matter halo triaxiality on the evolution of galactic disks. We do this by running a series of collisionless N-body models. In a first set of models we place the galactic disk within an oblate halo at various orientations and examine the resulting evolution. In our second set we construct fully self-consistent models of a stellar disk embedded within a spherical halo, with an impacting external dark matter dwarf galaxy. After evolving the simulations for a Hubble time, we examine the disk orientation and warping along with other quantities such as bar …

Clea Labs For Planetary Astronomy Bottled For Silicon Macintosh, Yuktha Shetty, Hansika Reddy Bandela, Jack C. Straton

Physics Faculty Publications and Presentations

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs were developed for Windows, but the authors have bottled them for Silicon Macintosh computers.

Reconnection-Driven Electron Acceleration, Ripudaman Singh Nirwan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Magnetic reconnection converts the magnetic energy available in a plasma to the kinetic energy of its constituent particles. In the simplest case, it occurs between anti-parallel magnetic field lines meeting in a plane. Another variant known as ‘component reconnection’ involves field lines reconnecting at an angle, giving a non-zero magnetic field component perpendicular to the plane of reconnection. This component is known as the ‘guide field’ and it is normalized to the reconnecting field in the literature. The guide field controls the particle-scale dynamics of reconnection and influences the ensuing particle acceleration.

Component reconnection occurs in the Earth’s magnetosphere, along …

From Bobcat To Bursts: Multi-Messenger Constraints On Supermassive Black Holes And Binaries, Jessica Sydnor

Graduate Theses, Dissertations, and Problem Reports (ETD)

Supermassive black hole binaries (SMBHBs) are a natural consequence of hierarchical galaxy formation and evolution. When galaxies merge, their central supermassive black holes (SMBHs) are expected to form bound pairs that evolve from kiloparsec to sub-parsec separations under the influence of dynamical friction, stellar scattering, and gas dynamics. Ultimately, these SMBHs reach the regime where gravitational wave emission dominates and drives the final inspiral and coalescence. Understanding the formation, evolution, and observational signatures of SMBHBs is critical to advancing multi-messenger astrophysics, particularly in the era of pulsar timing arrays (PTAs) and the upcoming Laser Interferometer Space Antenna (LISA), which opens …

On The Evidence For The Violation Of The Equivalence Principle In Disk Galaxies, Corey Sargent, William Clark, Antonia Seifert, Alicia Mand, Emerson Rogers, Adam Lane, Alexandre Deur, Balša Terzić

Physics Faculty Publications

We examine the claimed observations of a gravitational external field effect (EFE) reported by Chae et al. We show that observations suggestive of the EFE can be interpreted without violating Einstein’s equivalence principle, namely from known correlations between the morphology, the environment, and dynamics of galaxies. While Chae et al.’s analysis provides a valuable attempt at a clear test of modified Newtonian dynamics, an evidently important topic, a re-analysis of the observational data does not permit us to confidently assess the presence of an EFE or to distinguish this interpretation from that proposed in this article.

Scaling Laws For Diffusion In Crystallized Plasma From Molecular Dynamics, Dany Yaacoub

Theses and Dissertations

Diffusion coefficients for crystallized Coulomb plasmas are essential microphysics input for modeling white dwarf cores and neutron star crusts. Solving for diffusion coefficients require running large molecular dynamics simulations with thousands of particles over millions of timesteps. The diffusion in a crystallized plasma has been largely ignored and is often taken to be zero in stellar evolution codes. We find that not only is this incorrect, but we find that the diffusion in a crystallized plasma can be modeled completely using a universal scaling law independent of screening. Our simulations also show that the dominant mode of diffusion in a …