Other Astrophysics and Astronomy Commons^™

Enhanced Nuclear Binding Near The Proton Drip Line Opens Possible Bypass Of The 64Ge Rapid Proton Capture Process Waiting Point, Zachary Meisel, W.-J Ong, J. S. Ranhawa

Faculty Publications

We performed astrophysics model calculations with updated nuclear data to identify a possible bypass of the ⁶⁴Ge waiting point, a defining feature of the rapid proton capture (rp) process that powers type I X-ray bursts on accreting neutron stars. We find that the rp-process flow through the 64Ge bypass could be up to 36% for astrophysically relevant conditions. Our results call for new studies of ⁶⁵Se, including the nuclear mass, β-delayed proton emission branching, and nuclear structure as it pertains to the 64As(p, γ) reaction rate at X-ray burst temperatures.

A Catalytic Pathway For The Formation Of Cyanobenzene In Nitrogen-Rich Environments And The Spectroscopy Of The Reactive Intermediates, Vincent J. Esposito, Silvia Alessandrini, David Dubois, Ryan Fortenberry

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The catalytic reaction of isocyanobenzene (C₆H₅NC) with NCN⁻ produces cyanobenzene (C₆H₅NC) through various highly stable reactive intermediate species. Nitrogen-rich environments such as Titan’s atmosphere serve as favorable locations to study reaction pathways involving nitrogenated species contributing to organic growth. Formation pathways of cyanobenzene have been characterized, but none with the contribution of anions or phenyl groups. In regions with a high abundance of nitrogen anions, such as Titan’s atmosphere, reactions with species such as NCN⁻ may play a role in the formation of cyanobenzene. Highly accurate computational methods are used …

Transmutation, Sam Berger

MFA in Visual Art

My artistic practice is about change itself. I am inspired by the doubling and layering effects that came out of Surrealist Photography. Scale, fracture, and doubling are intentional components of my process. I combine those methods to create complex works of art, focusing on the untamable light that I hope to capture when making my images, which often are self portraits. Poetry is an integral element of this thesis text as well as my art making process. Through my poetic work I hope to offer my audience a glimpse into how I see and experience the world. This thesis text …

The Search For Slow Particles And Magnetic Monopoles With Nova, John Clark

Poster Presentations

Singular magnetic poles, north or south, have been theorized to exist for hundreds of years. In the modern day, the elusive singular magnetic pole still remains undiscovered. The appearance of this particle would help confirm many Grand Unified Theories, GUTs, and revolutionize our understanding of some of the fundamental forces of the universe. Fermilab's NOvA collaboration is working on ways to screen and detect magnetic monopoles and other slow-moving particles coming from outer space alongside their main mission to study neutrinos. The aim of this work is to determine and improve the Far Detector’s efficiency at identifying slow moving particles. …

Simulations Of Magnetar Spin-Down Lifetimes Using Magnetic Braking Models, Sophie Wessel

Honors College Theses

The beginnings of magnetar lifetimes are not very well understood. It is important to improve our understanding of magnetar origins in order to investigate possible evolutionary connections to other classes of NS, such as X-ray dim isolated NSs (XDINSs). Here we follow in the steps of another paper1 in modeling the spin evolution of magnetars, utilizing two avenues of evolution: one involving exponential B-field decay, and the other involving suband super-exponential B-field decay. We replicate the results of the paper, utilizing Monte Carlo methods to generate and evolve synthetic populations of magnetars, which are then compared to the current known …

Effects Of The Gravity Gradient On The Path Of 1i/‘Oumuamua, Hannah R. Richardson

Poster Presentations

In October 2017, the asteroid 1I/’Oumuamua first passed into viewing range [1]. The asteroid is notable for being the first interstellar object to enter the solar system. 1I/’Oumuamua was also unusual in its geometry; it is thought to have an aspect ratio of 6:1 and a length of approximately 400 m [2] [3]. The asteroid was observed to experience a non-Keplerian acceleration estimated to be on the order of 1×10−6 m s-2 Several theories have been proposed for the cause of this acceleration, all of which are non-gravitational in nature: volatile outgassing, photon pressure, and solar winds [1][4]. However, none …

Effects Of The Gravity Gradient On The Path Of 1i/‘Oumuamua, Hannah R. Richardson

Honors Theses

In October 2017, the asteroid 1I/’Oumuamua first passed into viewing range [1]. The asteroid is notable for being the first interstellar object to enter the solar system. 1I/’Oumuamua was also unusual in its geometry; it is thought to have an aspect ratio of 6:1 and a length of approximately 400 m [2] [3]. The asteroid was observed to experience a non-Keplerian acceleration estimated to be on the order of 1⇥10−6 m s2 . Several theories have been proposed for the cause of this acceleration, all of which are non-gravitational in nature: volatile outgassing, photon pressure, and solar winds [1][4]. However, …

A Spectroscopic Survey Of Atmospheres Of Super-Earths, Luke Brust

Honors Theses

Recent research has made it possible to use spectroscopy to analyze the composition of the atmospheres of exoplanets, planets that orbit other stars. Most projects thus far have focused on the atmospheres of gas giants, as it is less challenging to observe them with available equipment. This project studies the atmospheres of four Super- Earths, planets that have a mass greater than the Earth but smaller than Neptune. This is accomplished by processing the raw spectroscopic data from the Hubble Space Telescope and modeling the atmosphere using the program 𝝉-Rex3. This survey found clear results from two of the selected …

Probing The 'Mev Gap': Discovery And Characterization Of Persistent And Transient Mev-Gev Gamma-Ray Sources With The Fermi Large Area Telescoope, Scott Joffre

All Dissertations

The MeV Gap is a moniker for the energy regime E~0.1-100 MeV that has lacked sensitive observations for the last 20 years. This is not out of scientific disinterest, but observational challenges. The only instrument currently available to make observations in the MeV Gap is the Fermi Large Area Telescope (LAT). For the first time ever, Fermi-LAT has been leveraged to push its observational capabilities to its absolute lower energy limit to end this 20-year observational gap. Observing the MeV sky is imperative for identifying some of the most luminous galaxies in the Universe known as blazars. The brightest blazars …

Dissolving Sand Into Fog - Portraying Long Term Temporal Illusions Through Music, Kyle Bergler

Honors Projects

Long-term temporal illusions permeate our day-to-day lives, but due to their highly subjective nature, few are familiar with them. To help introduce these topics in a way that lets a wider audience connect individually with them, I composed three works for percussion ensembles, each in a different style, and each portraying one or multiple long-term temporal illusions. All of these pieces were composed and rehearsed throughout the spring 2025 semester and premiered at my senior recital on April 19, 2025.

Ionospheric Evidence Of Lobe Reconnection For Northward Imf, Dora Csonge, Gerard Fasel, John Mann, Audrey Daucher, Owen Bradley, Aidan Hulbert, Thomas Lewer, Sun-Hee Lee, F. Sigernes, D. Lorentzen

Seaver College Research And Scholarly Achievement Symposium

It is believed that magnetic reconnection is one of the main mechanisms to transfer energy and momentum from the for the solar wind into the terrestrial environment. Dungey suggested that magnetic reconnection occurs on the dayside magnetosphere when the interplanetary magnetic field (IMF) is southward. Poleward moving auroral forms (PMAFs) have been identified in past studies as Ionospheric signatures of magnetic reconnection on the dayside.

However, magnetic reconnection can also occur for other geometrical orientations of the IMF. This presentation presents possible examples, 1 December 2021, for lobe reconnection during periods when the IMF x-component is negative, coupled with a …

Dayside Auroral Oval Expansion, Magnetic Flux Erosion, And Substorms, Dora Csonge, Parker Para, Gerard Fasel, Owen Bradley, Gasia Excel, Makena Swenski, Rachel Rodriguez, Sun-Hee Lee, John Mann, F. Sigernes, D. Lorentzen

Seaver College Research And Scholarly Achievement Symposium

Magnetic flux is eroded from the dayside magnetosphere when the interplanetary magnetic field (IMF) turns southward. During this period, the dayside auroral oval shifts equatorward as magnetic flux is transported anti-sunward to the magnetotail. Poleward-Moving Auroral Forms (PMAFs) are thought to be the ionospheric footprints of the flux tubes which are formed and transported tailward. Afterwards, magnetic reconnection occurs in the magnetotail, resulting in a substorm.

This study looks at the time between the onset of dayside magnetic reconnection and the onset of a substorm. Rates of dayside auroral oval equatorward shifts after southward turnings of the IMF are presented, …

Dayside North-South Aligned Auroral Arcs, Taiel Ramirez, Gerard J. Fasel, Wyatt Farrar, Mason Woolfolk, Andrea Black, Cullen Diggs, Clay Shin, Jordan Chiu, Sun-Hee Lee, John Mann, Fred Sigernes, Dag A. Lorentzen

Seaver College Research And Scholarly Achievement Symposium

Observations of North-South auroral arcs (or Sun-aligned) have been recorded for many years. Discrete North-South auroral arcs are located between 73-84° MLAT and are usually associated moderate auroral activity, low solar wind dynamic pressure, and a small IMF z-component. Some observations reported quasi-periodic poleward motions of North-South aligned dayside auroral arcs. This current statistical study contains nine years of All-Sky Camera images obtained from the Boreal Aurora Camera Constellation (BACC) from the Kjell Henriksen Observatory (KHO) in Longyearbyen, Svalbard (GEO: 78.148 N, 16.043 E; AACGM: 75.24 N, 111.21 E). The characteristics of discrete North-South dayside auroral arcs, including spatial and …

Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard

Spring Showcase for Research and Creative Inquiry

This research project focuses on the computational modeling of astrophysical systems using Femap with NX Nastran. The goal was to simulate and analyze the vibrational behavior and structural deformation of celestial bodies under different material compositions and collision conditions. Materials such as iron, granite, titanium, and models for white dwarf stars were used to investigate how varying physical properties affect the systems' dynamic responses. Both isotropic and anisotropic models were created to represent realistic astrophysical materials. Through static and modal analyses, the study explored how internal structure and material stiffness influence the reaction of celestial objects to applied forces and …

19ne Excited States In Explosive Nucleosynthesis, Khang Pham

LSU Doctoral Dissertations

Classical novae and Type I X-ray bursts are stellar explosions that occur in binary systems, where nuclear reactions involving ¹⁹Ne play a crucial role in nucleosynthesis. In novae, the destruction of ¹⁸F via the ¹⁸F(p,alpha)¹⁵O reaction significantly affects the amount of ¹⁸F remaining in the ejecta, directly influencing the detectability of predicted 511-keV gamma rays. However, discrepancies between observed and predicted ¹⁸F abundances highlight uncertainties in the reaction rates, primarily due to unknown properties of resonances in the compound nucleus ¹⁹Ne. In Type I X-ray bursts, the ¹⁵O(alpha,gamma)¹⁹Ne reaction …

Measuring Cosmic Rays With Muon Detectors (Quarknet), Aiden Burton, Jack W. Maseberg

SACAD: Scholarly Activities

We report measurement of atmospheric muon particles originating from cosmic rays. Using four QuarkNet project scintillators in an unstacked geometry, we are counting muons in coincidence with each other. We are currently refurbishing a second detector apparatus and will soon be capable of measuring coincidence events for larger shower surface areas using a total of eight scintillators.

Robust Spacecraft Autonomy For Deep Space Exploration In Special Euclidean Group Se(3), Matthew Wittal

Doctoral Dissertations and Master's Theses

Over the past half-century, humanity has gained extensive experience conducting manned spaceflight near Earth. Arguably, "near Earth" could even include the Moon — the most distant destination humans have reached. However, "near" in this work primarily refers low Earth orbit (LEO). One could argue that we have not truly left Earth since the Apollo, as spacecraft in some LEOs remain subject to atmospheric drag thus emphasizing their continued connection to Earth's immediate environment. Reflecting on this, it becomes clear that humanity has largely remained bound to Earth’s immediate vicinity since the Apollo missions reached the Moon. However, that is set …

Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Infrared (IR) cooling of polycyclic aromatic hydrocarbon (PAH) molecules is a major radiative stabilization mechanism of PAHs present in space and is the origin of the aromatic infrared bands (AIBs). Here, we report an anharmonic cascade model in a master equation framework to model IR emission rates and emission spectra of energized PAHs as a function of internal energy. The underlying (simple harmonic cascade) framework for fundamental vibrations has been developed through the modeling of cooling rates of PAH cations and other carboneaous ions measured in electrostatic ion storage ring experiments performed under “molecular cloud in a box” conditions. The …

A Sensitivity Analysis Of The Modeling Of Polycyclic Aromatic Hydrocarbon Emission In Galaxies, A. Maragkoudakis, C. Boersma, P. Temi, J. D. Bregman, L. J. Allamandola, Vincent J. Esposito, A. Ricca, E. Peeters

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have conducted a sensitivity analysis on the mid-infrared spectral decomposition of galaxies and the modeling of the polycyclic aromatic hydrocarbon (PAH) emission spectrum with the NASA Ames PAH Infrared Spectroscopic Database (PAHdb) to assess the variance on the average galaxy PAH population properties under a grid of different modeling parameters. We find that the short-low and short-low+long-low Spitzer-IRS decomposition with PAHFIT provides consistent modeling and recovery of the 5–15 μm PAH emission spectrum. For PAHdb modeling, application of a redshift to the calculated spectra to account for anharmonic effects introduces a 15%–20% variance on the derived parameters, while its …

Photolysis And Sublimation Chemistry Of Ammonium Cyanide With Relevance To Cometary Environments, O. H. Wilkins, K. M. Yocum, Vincent J. Esposito, E. Harel, S. N. Milam, P. A. Gerakines

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bulk nitrogen is depleted in solar system objects, including the terrestrial planets, chondritic meteorites, and comets. Recently, it was suggested that cometary nitrogen may be locked up in ammonium salts—ionic solids comprising ammonia (NH₃) and an acid such as hydrogen cyanide (HCN)—based on Rosetta/ROSINA data from comet 67P/Churyumov–Gerasimanko. Among the proposed salts to have been found in 67P were ammonium cyanide (NH₄CN) and ammonium cyanate (NH₄OCN), which were inferred from identifying HCN, cyanamide (NH₂CN), and isocyanic acid (HNCO) in the mass spectrometry data collected in the coma of 67P. However, the relationship …