Astrophysics and Astronomy Commons^™

Planetary Atmospheres, Ryan M. Johnson

Physics Theses & Dissertations

Planetary atmospheres are frequently studied using a number of spectroscopic methods. One of these is observing spectra to analyze what molecules are present or chemical reactions may be taking place. To this end, we have produced a line list of the electronic a¹Δ−X³Σ⁻ and b¹Σ⁺−X³Σ− transitions of SO. Additionally, a line list pure rovibrational transitions of the a¹Δ and X³Σ⁻ states were produced, but lacked the necessary experimental data for the b¹Σ⁺ state. These line lists can be used in further …

Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs

Senior Honors Papers / Undergraduate Theses

The observation of axions could revolutionize the world of physics. Through microwave frequency cavity readout of the photons associated with these axions, the ADMX project at WashU utilizes multiple different forms of the Josephson junction (JJ), a superconductive circuit element. The physics behind the JJ are essential to understanding its operation for resonant cavity readout in addition to parametric amplification. Parametric amplifiers produced using JJs can approach the signal-to-noise ratio set by quantum mechanics, and prove essential for the amplification chain used by the ADMX experiment for axionic detection. The limits of these amplifiers are set by the noise tuning …

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.

Optical Spring Tracking For Enhancing Quantum-Limited Interferometers, Scott M. Aronson

LSU Doctoral Dissertations

Gravitational waves were first predicted by Albert Einstein in 1916. Calculations in the 1970s by Rainer Weiss showed an interferometer of sufficient size could realistically detect gravitational waves, which led to a grant by the National Science Foundation (NSF). With steady progress and over decades of funding by the NSF, the construction of two full scale 4km interferometers was approved and began construction in 1994. This project, coined LIGO the Laser Interferometer Gravitational-wave Observatory, came to be a worldwide collaboration of scientists dedicated to the discovery and study of gravitational waves. In 2015, both LIGO detectors detected a coincident inspiral …

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 …

A Sensitivity Curve Approach To Tuning A Pulsar Timing Array In The Detection Era, Jeremy G. Baier, ‪Jeffrey S. Hazboun, Joseph D. Romano

Physics & Astronomy Faculty Publications

As pulsar timing arrays (PTAs) transition into the detection era of the stochastic gravitational wave background (GWB), it is important for PTA collaborations to review and possibly revise their observing campaigns. The detection of a 'single source' would be a boon for gravitational astrophysics, as such a source would emit gravitational waves for millions of years in the PTA frequency band. Here we present generic methods for studying the effects of various observational strategies, taking advantage of detector sensitivity curves, i.e. noise-averaged, frequency-domain detection statistics. The statistical basis for these methods is presented along with myriad examples of how to …

Contact Binary Stars: A Roadmap To Their Nature And Evolution, Larry A. Molnar

University Faculty Publications and Creative Works

Notre Dame Physics & Astronomy Dept. Seminar, March 18th, 2025 with students L. Carr, J. Darrow Former students: J. Lau, L. Henderson, A. Avery, G. M. Le, M. Blain

The Baryonic Tully-Fisher Relation. Ii. Stellar Mass Models, Francis Duey, Stacy Mcgaugh

Faculty Scholarship

We present new color-ϒ* (mass-to-light ratio) models to convert Wide-field Infrared Survey Explorer W1 fluxes into stellar masses. We outline a range of possible star formation histories and chemical evolution scenarios to explore the confidence limits of stellar population models on the value of ϒ*. We conclude that the greatest uncertainties (around 0.1 dex in ϒ*) occur for the bluest galaxies with the strongest variation in recent star formation. For high-mass galaxies, the greatest uncertainty arises from the proper treatment of bulge-disk separation in which to apply different ϒ* relations appropriate for those differing underlying stellar populations. We compare our …

Advanced Ligo Detector Performance In The Fourth Observing Run, E. Capote, W. Jia, N. Aritomi, M. Nakano, V. Xu, R. Abbott, I. Abouelfettouh, R. X. Adhikari, Francisco Llamas Villarreal, Volker Quetschke

Physics & Astronomy Faculty Publications

On May 24, 2023, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), joined by the Advanced Virgo and KAGRA detectors, began the fourth observing run for a two-year-long dedicated search for gravitational waves. The LIGO Hanford and Livingston detectors have achieved an unprecedented sensitivity to gravitational waves, with an angle-averaged median range to binary neutron star mergers of 152 and 160 Mpc, and duty cycles of 65.0% and 71.2%, respectively, with a coincident duty cycle of 52.6%. The maximum range achieved by the LIGO Hanford detector is 165 Mpc and the LIGO Livingston detector 177 Mpc, both achieved during the second …

The Effect Of Vera C. Rubin Observatory Cadence Selections On Kilonova Detectability, Cristina Andrade, Raiyah Alserkal, Luis Salazar Manzano, Emma Martin, Igor Andreoni, Michael W. Coughlin, Nidhal Guessoum, Liliana Rivera Sandoval

Physics & Astronomy Faculty Publications

The discovery of the optical/infra-red counterpart (AT2017gfo) to the binary neutron star gravitational-wave detection (GW170817), which was followed by a short gamma-ray burst (GRB 170817), marked a groundbreaking moment in multi-messenger astronomy. To date, it remains the only confirmed joint detection of its kind. However, many experiments are actively searching for similar fast-fading electromagnetic counterparts, known as kilonovae. Fortunately, the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) provides excellent prospects for identifying kilonova candidates either from, or independent of, gravitational-wave and GRB triggers. Cadence choices for LSST surveys are especially important for maximising the likelihood of …

Ground-Based Reconnaissance Observations Of 21 Exoplanet Atmospheres With The Exoplanet Transmission Spectroscopy Imager, Ryan J. Oelkers, Luke M. Schmidt, Erika Cook, Mary Anne Limbach, Darren L. Depoy, J. L. Marshall, Jimmy Ardoin, Mitchell Barry, Evan Batteas, Alexandra Boone

Physics & Astronomy Faculty Publications

One of the most prolific methods of studying exoplanet atmospheres is transmission spectroscopy, which measures the difference between the depth of an exoplanet's transit signal at various wavelengths and attempts to correlate the depth changes to potential features in the exoplanet's atmosphere. Here we present reconnaissance observations of 21 exoplanet atmospheres measured with the Exoplanet Transmission Spectroscopy Imager (ETSI), a recently deployed spectrophotometer on the McDonald Observatory Otto Struve 2.1 m telescope. ETSI measurements are mostly free of systematics through the use of a novel observing technique called common-path multiband imaging (CMI), which has been shown to achieve photometric color …

Implications Of Magnetic Evolution On Coronal Loop Thermal Variation Prior To Solar Flares, Kara L. Kniezewski

Theses and Dissertations

Solar flares are intense bursts of electromagnetic radiation, which occur due to a rapid destabilization and reconnection of the magnetic field. While flares are a magnetic phenomena, very little attention has been paid to thermal conditions in the corona prior to flare onset. This study serves as a follow-on to Kniezewski et al., 2024, where the EUV emission from coronal loops was observed to vary substantially and without any coherence between channels before 53 off-limb flares. These variations suggest multiple mechanisms within the coronal magnetic field are responsible for heating fluctuations. Here, the 3D magnetic field is modeled using a …

The Nanograv 15 Yr Dataset: Posterior Predictive Checks For Gravitational-Wave Detection With Pulsar Timing Arrays, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Jeremy G. Baier, Paul T. Baker, Bence Becsy, Joey S. Key, Jing Luo, Joseph D. Romano

Physics & Astronomy Faculty Publications

Pulsar timing array experiments have reported evidence for a stochastic background of nanohertz gravitational waves consistent with the signal expected from a population of supermassive black hole binaries. Their analyses assume power-law spectra for intrinsic pulsar noise and for the background, as well as a Hellings-Downs cross-correlation pattern among the gravitational-wave-induced residuals across pulsars. These assumptions may not be realized in actuality. We test them in the NANOGrav 15 yr dataset using Bayesian posterior predictive checks. After fitting our fiducial model to real data, we generate a population of simulated dataset replications. We use the replications to assess whether the …

Swift-Bat Guano Follow-Up Of Gravitational-Wave Triggers In The Third Ligo–Virgo–Kagra Observing Run, Gayathri Raman, Samuele Ronchini, James Delaunay, Aaron Tohuvavohu, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

We present results from a search for X-ray/gamma-ray counterparts of gravitational-wave (GW) candidates from the third observing run (O3) of the LIGO–Virgo–KAGRA network using the Swift Burst Alert Telescope (Swift-BAT). The search includes 636 GW candidates received with low latency, 86 of which have been confirmed by the offline analysis and included in the third cumulative Gravitational-Wave Transient Catalogs (GWTC-3). Targeted searches were carried out on the entire GW sample using the maximum-likelihood Non-imaging Transient Reconstruction and Temporal Search pipeline on the BAT data made available via the GUANO infrastructure. We do not detect any significant electromagnetic emission that is …

A Bibliometric Study Of Astronomy And Geoscience Doctoral Dissertations, Nora Boyle, Mary Schlembach

Faculty Journal Articles

A bibliometric analysis was conducted over the bibliographies of astronomy and geology doctoral dissertations written between 1970 and 2020 in order to review the document types that are utilized and cited. An investigation was made of various cited reference ages and how cited references in dissertations have evolved with the advent of electronic resources and preprint services. Our study examined 50 astronomy and 50 geology dissertations with 10 dissertations selected from each decade (n = 100). Results measured included 13,475 total references and the study found that references to journal articles increased, and book citations have decreased in both …

Hierarchical Search Method For Gravitational Waves From Stellar-Mass Binary Black Holes In Noisy Space-Based Detector Data, Yao Fu, Yan Wang, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

Future space-based laser interferometric detectors, such as the Laser Interferometer Space Antenna (LISA), will be able to detect gravitational waves (GWs) generated during the inspiral phase of stellar-mass binary black holes (SmBBHs). These detections contain a wealth of important information concerning astrophysical formation channels and fundamental physics constraints. However, the detection and characterization of GWs from SmBBHs poses a formidable data analysis challenge, arising from the large number of wave cycles that make the search extremely sensitive to mismatches in signal and template parameters in a likelihood-based approach. This makes the search for the maximum of the likelihood function over …

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 …

From The University To The Universe: A Scientific And Historical Overview Of The West Mountain Observatory, Amber Zendejas, Dan Broadbent

BYU West Mountain Observatory Project

BACKGROUND

• November 1980 - Construction began on the observatory’s main building

• 1981 - Observations begin, away from Provo’s Light Pollution

• Located on West Mountain, west of Spanish Fork, UT

Single-Molecule Dna-Flow Stretching Assay As A Versatile Hybrid Tool For Investigating Dna-Protein Interactions, Sadaf Shehzad, Hyeongjun Kim

Physics & Astronomy Faculty Publications

Single-molecule techniques allow researchers to investigate individual molecules and obtain unprecedented details of the heterogeneous nature of biological entities. They play instrumental roles in studying DNA-protein interactions due to the ability to visualize DNA or proteins and to manipulate individual DNA molecules by applying force or torque. Here, we describe single-molecule DNA-flow stretching assays as hybrid tools that combine forces with fluorescence. We also review how widely these assays are utilized in elucidating working mechanisms of DNA-binding proteins. Additionally, we provide a brief explanation of various efforts to prepare DNA substrates with desired internal protein-binding sequences. More complicated needs for …

Deep Learning-Based Superconductivity Prediction And Experimental Tests, Daniel Kaplan, Adam Zheng, Joanna Blawat, Rongying Jin, Robert J. Cava, Viktor Oudovenko, Gabriel Kotliar, Anirvan M. Sengupta, Weiwei Xie

Faculty Publications

The discovery of novel superconducting materials is a long-standing challenge in materials science, with a wealth of potential for applications in energy, transportation and computing. Recent advances in artificial intelligence (AI) have enabled expediting the search for new materials by efficiently utilizing vast materials databases. In this study, we developed an approach based on deep learning (DL) to predict new superconducting materials. We have synthesized a compound derived from our DL network and confirmed its superconducting properties in agreement with our prediction. Our approach is also compared to previous work based on random forests (RFs). In particular, RFs require knowledge …