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Articles 31 - 60 of 8894
Full-Text Articles in Astrophysics and Astronomy
Helio: Heliophysics Enhanced Learning For Intelligent Orbits, Kylie Nager, James Kirk
Helio: Heliophysics Enhanced Learning For Intelligent Orbits, Kylie Nager, James Kirk
Discovery Day - Daytona Beach
HELIO: Heliophysics Enhanced Learning for Intelligent Orbits Satellite constellations operating in near-Earth space are increasingly vulnerable to space weather disturbances, such as solar flares, coronal mass ejections (CMEs), and high-speed solar wind streams, which degrade communications, destabilize attitude control, and accelerate orbital decay. These disturbances directly threaten mission continuity, constellation availability, and space asset survivability. Current protective approaches rely primarily on ground-based alerts and lack integration with broader space domain awareness, which results in programmed reactive protocols that are often initiated too late to prevent performance degradation and asset loss. The HELIO project addresses this gap by turning space-weather forecasts …
Precise Stellar Age Constraints And Habitable Zone Evolution In Exoplanet Systems, Grace Henry
Precise Stellar Age Constraints And Habitable Zone Evolution In Exoplanet Systems, Grace Henry
Discovery Day - Daytona Beach
Accurate stellar ages are fundamental to interpreting the evolutionary histories of habitable zone (HZ) planets. Because stellar luminosity evolves over time, HZ boundaries migrate outward, meaning that present-day HZ planets may have experienced very different irradiation environments earlier in their evolution. Accurate ages are therefore required to estimate HZ residence times and place planetary habitability in an evolutionary context. We use the Bayesian Analysis of Stellar Evolution with nine parameters (BASE-9) code to constrain ages and masses for exoplanet host stars with planets located in the HZ. Our sample includes single stars with effective temperatures of 4475–7200 K that host …
Tess Study Of Wolf-Rayet Stars In The Large Magellanic Cloud, Benjamin Katz, Kassidy Myers, Bailey Wolf, Anthony Fabrega, William Punches
Tess Study Of Wolf-Rayet Stars In The Large Magellanic Cloud, Benjamin Katz, Kassidy Myers, Bailey Wolf, Anthony Fabrega, William Punches
Discovery Day - Daytona Beach
TESS Study of Wolf-Rayet Stars in the Large Magellanic Cloud Wolf-Rayet (WR) stars are massive and rare stars whose evolution is mainly changed by stellar winds or binary interactions. In a lot of cases, WR stars are found in binary systems with a companion star, often an O-type star, which can help astronomers find the mass and other properties of the WR star. The Large Magellanic Cloud (LMC), located about 50 kpc from the Milky Way, has a lower metallicity than the Milky Way which makes it a useful place to study Wolf-Rayet stars. For this project, we will study …
Unveiling Stellar Core Depletion In Ngc 4649 With Jwst Nircam, Sydney Krause
Unveiling Stellar Core Depletion In Ngc 4649 With Jwst Nircam, Sydney Krause
Discovery Day - Daytona Beach
Galaxies are considered to have depleted cores when the central region’s concentration of stars is lower than typical, a feature linked to supermassive black hole formation and vital in galaxy evolution studies. In this project, “Unveiling Stellar Core Depletion in NGC 4649 with JWST NIRCam”, Space-based archival data from the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam) was utilized for several forms of analysis. Initial analysis involved accessing these images via SAO DS9, an astrophysics software for viewing and manipulating files. These images were analyzed using Photoutils, a Python based coding package, part of the Astropy extension. To …
Modeling Doppler-Shifted Solar Spectra From Simulated Asteroidal Dust Populations Using Orbital Evolution Codes, Skylar G. Butler, Jarrett Dieterle
Modeling Doppler-Shifted Solar Spectra From Simulated Asteroidal Dust Populations Using Orbital Evolution Codes, Skylar G. Butler, Jarrett Dieterle
Discovery Day - Daytona Beach
We investigate how orbital properties of interplanetary dust particles produce Doppler-shifted solar absorption lines using synthetic spectra generated from particle outputs of a numerical orbital evolution code. The code is based on the Ipatov dynamical model, written in Fortran and using the SWIFT integration package to track the evolution of dust particles originating from asteroid and comet populations. The program reads input files containing particle orbital elements and heliocentric positions, along with planetary parameters and integration settings, and computes the time evolution of particle trajectories under gravitational perturbations. The resulting particle states are then used to generate synthetic spectra by …
Ngc 4374 With Jwst/Nircam: A Central Structural Analysis Revealing A Depleted Core And Agn, Elizabeth Crevinston
Ngc 4374 With Jwst/Nircam: A Central Structural Analysis Revealing A Depleted Core And Agn, Elizabeth Crevinston
Discovery Day - Daytona Beach
We use James Webb Space Telescope’s (JWST) Near Infrared Camera (NIRCam) F150W imaging to study the central regions of massive elliptical galaxies, focusing on their partially depleted cores. These cores are thought to form when a binary supermassive black hole (SMBH) ejects stars from the central regions through dynamical three-body interactions. After the binary coalesces, gas accretion onto the newly formed SMBH can trigger a compact active galactic nucleus (AGN), which plays a key role in regulating star formation and shaping galaxy structure. With JWST NIRCam, we extracted the surface brightness profile of NGC 4374, a giant elliptical galaxy in …
Gwtc-4.0: Constraints On The Cosmic Expansion Rate And Modified Gravitational-Wave Propagation, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang
Gwtc-4.0: Constraints On The Cosmic Expansion Rate And Modified Gravitational-Wave Propagation, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang
Physics & Astronomy Faculty Publications
We analyze data from 142 of the 218 gravitational-wave (GW) sources in the fourth LIGO-Virgo-KAGRA Collaboration (LVK) Gravitational-Wave Transient Catalog (GWTC-4.0) to estimate the Hubble constant H0 jointly with the population properties of merging compact binaries. We measure the luminosity distance and redshifted masses of GW sources directly; in contrast, we infer GW source redshifts statistically through (i) location of features in the compact object mass spectrum and merger rate evolution, and (ii) identifying potential host galaxies in the GW localization volume. Probing the relationship between source luminosity distances and redshifts obtained in this way yields constraints on cosmological parameters. …
The Computed Microwave Spectrum Of The Protonated Fullerene C60H+, Laszlo Nemes, Jos Oomens, Vincent J. Esposito, Vincent Boudon, Alexander G. G. M. Tielens
The Computed Microwave Spectrum Of The Protonated Fullerene C60H+, Laszlo Nemes, Jos Oomens, Vincent J. Esposito, Vincent Boudon, Alexander G. G. M. Tielens
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The largest known molecule in the interstellar medium of galaxies, C60, has been detected in its neutral and cationic form through its vibrational, UV-driven fluorescence emission spectrum and its electronic absorption spectrum, respectively. The detection of several polycyclic aromatic hydrocarbon molecules through their pure rotation spectrum in cold, dense, molecular cloud cores suggests that C60 might be present in these environments as well. The low flux of UV pumping photons in molecular cloud cores and the absence of suitably bright background stars, make detection of C60 and its cation through the commonly used methods impractical. As …
Measuring Cosmic Expansion From Early To Late Times Using Quasars, Galaxies, & Local Supernovae, Rajeev Vaisakh
Measuring Cosmic Expansion From Early To Late Times Using Quasars, Galaxies, & Local Supernovae, Rajeev Vaisakh
Physics Theses and Dissertations
This dissertation investigates the evolution of cosmic expansion across a wide redshift ($z$) range by combining measurements from quasars \& galaxies in the distant universe $(z > 0.8)$ with those obtained from stripped-core collapse supernovae observations from the nearby universe $(z < 0.1)$. Using the DESI spectroscopic survey, we analyze large-scale clustering from quasars over $0.8 < z < 2.1$ and emission line galaxies over $0.8 < z < 1.6$, contributing to DESI DR2 BAO and full-shape measurements of cosmic expansion and structure growth. Combined with BBN in flat $\Lambda$CDM, DESI DR2 BAO gives $H_0 = 68.51 \pm 0.58$ km s$^{-1}$ Mpc$^{-1}$, while combinations of DESI BAO with CMB and supernova data show a preference for evolving dark energy, with representative constraints such as $w_0 = -0.752 \pm 0.057$ and $w_a = -0.86^{+0.23}_{-0.20}$ for DESI+CMB+DESY5. Using the ROTSE-III Supernova Survey and the expanding photosphere method (EPM), we measure distances to a sample of six supernovae for which the thermal phase can be clearly identified. This analysis focuses on testing whether reliable EPM distances can be obtained for this population. The resulting distances will eventually be compared with independent estimates from the literature. Establishing consistency with these external measurements represents an important step toward applying this methodology to larger samples, with the eventual goal of using ROTSE supernova distances to provide an independent measurement of the local Hubble constant.
Mining Time Series Shapelets And Association Rules For Solar Flare Prediction, Drew Watson
Mining Time Series Shapelets And Association Rules For Solar Flare Prediction, Drew Watson
All Graduate Theses and Dissertations, Fall 2023 to Present
Solar flares are the largest explosions in the solar system; they are caused by changes in the Sun’s magnetic field. Strong solar flares can disrupt power systems, damage satellites, and interfere with radio communication, so improving flare prediction is important. This thesis develops a way to predict severe solar flares while also helping researchers understand why those predictions are made. The approach looks for short patterns in solar magnetic field data that are linked to future flare activity. It then studies how these patterns appear together and in what order they happen over time. By doing this, the research not …
Ultraviolet Imaging Of Sr 12 C With Hst/Wfc3: Accretion And Variability Of A Giant Planet At The End Stages Of Growth, Claire O. Finley, Brendan P. Bowler, Ya-Lin Wu, Adam L. Kraus, Yifan Zhou, Yuhiko Aoyama, William Best, Ian Czekala, Catherine C. Espaillat, Katherine B. Follette, Gregory J. Herczeg, Raquel A. Martinez, Connor E. Robinson, Quang H. Tran, K. Ward-Duong
Ultraviolet Imaging Of Sr 12 C With Hst/Wfc3: Accretion And Variability Of A Giant Planet At The End Stages Of Growth, Claire O. Finley, Brendan P. Bowler, Ya-Lin Wu, Adam L. Kraus, Yifan Zhou, Yuhiko Aoyama, William Best, Ian Czekala, Catherine C. Espaillat, Katherine B. Follette, Gregory J. Herczeg, Raquel A. Martinez, Connor E. Robinson, Quang H. Tran, K. Ward-Duong
Astronomy: Faculty Publications
Many details of the gas accretion phase during giant planet formation remain untested. We present new 0.2–0.7 μm UV-through-red optical imaging of the young, wide-orbit planetary-mass companion SR 12 c from the Wide Field Camera 3 (WFC3) instrument on board the Hubble Space Telescope. SR 12 c exhibits strong accretion-related continuum excess blueward of∼5000 Å and clear signs of the Balmer jump at 3646 Å. We derive a total accretion luminosity of1.65 ±0.19× 10−5L⊙and a mass accretion rate of 8 ±2 × 10−12 M⊙yr−1. Based on its mass and age,SR12 c …
Tellurium Selenide Quantum Wires Synthesized By Pulsed Laser Ablation In Liquids, Rajendra Subedi, Francisco Ruiz-Zepeda, Iono Hill, Geraldine Hallais, Etienne Herth, Gregory Guisbiers
Tellurium Selenide Quantum Wires Synthesized By Pulsed Laser Ablation In Liquids, Rajendra Subedi, Francisco Ruiz-Zepeda, Iono Hill, Geraldine Hallais, Etienne Herth, Gregory Guisbiers
Faculty Scholarship
Tellurium–selenide (TexSe1-x) binary alloys are promising chalcogenide systems with tunable optoelectronic properties, yet their synthesis in quantumly confined one-dimensional forms remains limited. Here, we report the synthesis of TexSe1-x quantum wires (QWs) via a two-step pulsed laser ablation in liquids (PLAL) approach, enabling surfactant-free formation of alloyed nanostructures under non-equilibrium conditions. A tellurium colloid is first generated and subsequently exposed to selenium ablation, promoting in-situ alloying through repeated plasma-bubble interactions at high repetition rate. The resulting QWs exhibit an average diameter of ~17 ± 4 nm and a length of ~475 ± 46 nm. Structural and chemical analyses (XRD, Raman, …
Quantifying Dust Structure In An Elliptical Galaxy Via Optical–Near-Infrared Color Mapping: A Detailed Study Of Ngc 6251, Luke Reed
Theses and Dissertations
The giant elliptical galaxy NGC 6251 is a well-studied active radio galaxy that hosts one of the largest known relativistic jet systems, with a projected size of approximately 3 Mpc. In addition to its large-scale radio structure, the galaxy hosts a prominent circumnuclear dust feature surrounding the active nucleus, previously interpreted as a warped dust disk. This thesis focuses on the inner morphology and dust structure of NGC 6251 using archival Hubble Space Telescope observations obtained with the WFPC2 and NICMOS instruments.
The central structure of the galaxy was investigated across multiple wavelengths through image calibration, PSF modeling and subtraction, …
Emergent De Sitter Expansion And Closed Topology From The Cosmic Fabric Model As An Open Thermodynamic System: Resolving The Negative Bulk Modulus Paradox, T G. Tenev, C B. Ward, T F. Tenev, M F. Horstemeyer
Emergent De Sitter Expansion And Closed Topology From The Cosmic Fabric Model As An Open Thermodynamic System: Resolving The Negative Bulk Modulus Paradox, T G. Tenev, C B. Ward, T F. Tenev, M F. Horstemeyer
Faculty Publications and Presentations
The Cosmic Fabric Model establishes a continuum-mechanics isomorphism to General Relativity by representing physical space as an elastic three-dimensional hyperplate embedded in a four-dimensional spatial bulk. Reproducing vacuum kinematics requires a vanishing P-wave modulus, which in turn implies a negative bulk modulus—an apparent thermodynamic instability in a closed system. This paradox is resolved by recasting the framework as an open system: the instability is not pathological but instead drives cosmic expansion. In this interpretation, the observable universe is a lower-energy solid formed through continuous solidification from a higher-dimensional precursor fluid. Using multiplicative kinematics from finite-growth mechanics, the model shows that …
New Distance Distributions Of Asymptotic Giant Branch Stars And Their Role In Tracing Galactic Structure, Rajorshi Bhattacharya
New Distance Distributions Of Asymptotic Giant Branch Stars And Their Role In Tracing Galactic Structure, Rajorshi Bhattacharya
Physics & Astronomy ETDs
Asymptotic giant branch (AGB) stars are among the final evolutionary stages of low- and intermediate-mass stars and among the most luminous cool stellar populations in the Milky Way (MW). Their strong infrared emission allows them to be observed through regions of high interstellar extinction, making them useful tracers of the inner MW. However, their use is limited by unreliable distances because many are dust-obscured and variable, while geometric parallaxes are often unavailable or uncertain. This thesis develops statistical distance-estimation methods for large samples of oxygen-rich AGB stars. The resulting distances broadly agree with literature estimates, supporting their statistical reliability for …
Extending The Discovery Space Of Tess: Probing Underexplored Exoplanet Populations, Mallory L. Harris
Extending The Discovery Space Of Tess: Probing Underexplored Exoplanet Populations, Mallory L. Harris
Physics & Astronomy ETDs
This dissertation investigates how cold exoplanets can be identified despite the strong observational bias of exoplanet surveys toward short-period systems. Planets at wider orbital separations remain comparatively poorly constrained, limiting tests of planetary-system formation and the prevalence of outer architectures beyond compact systems. To address this gap, I use two complementary approaches. First, I develop a transit-search pipeline for TESS Full-Frame Images that identifies both isolated and repeated transit-like signals around nearby M dwarfs and characterizes the dominant false-positive classes that limit sensitivity in this regime. I then present TOI-904 c, the coldest planet discovered by TESS around an M …
An Investigation Of Tess M&Ms And The Occurrence Rate Of Transiting Circumbinary Planets, Dominic Oddo
An Investigation Of Tess M&Ms And The Occurrence Rate Of Transiting Circumbinary Planets, Dominic Oddo
Physics & Astronomy ETDs
Circumbinary planets (CBPs) are worlds which orbit two stars simultaneously. CBPs are excellent tests of the tenacity of planet formation, but are difficult to detect. The space-based NASA Transiting Exoplanet Survey Satellite (TESS) mission is a nearly all-sky survey designed to detect exoplanets transiting nearby stars. In this dissertation, I analyze the performance of TESS by comparing to the photometric precision of the ESA CHEOPS mission. Then, I define a catalog of low-mass eclipsing binaries (M&Ms), which are the best sources to search for CBPs. I describe my custom transit search methodology and apply it to the M&M catalog. I …
Quantum Control Of Qubits And Qudits In Neutral Atom Systems, Sri Datta Vikas Buchemmavari
Quantum Control Of Qubits And Qudits In Neutral Atom Systems, Sri Datta Vikas Buchemmavari
Physics & Astronomy ETDs
This dissertation explores control of neutral atom quantum systems across multiple levels of abstraction, from atomic physics to system-level fault tolerance, using optimal control to improve performance. First, we propose a Rydberg entangling gate based on dressing with only the qubit control field; an interaction energy near the Rabi frequency benefits both gate speed and Rydberg decay. Second, with Sandia National Laboratories, we show that leakage errors in neutral atom systems can be converted to atom loss errors and detected using two entangling gates with an auxiliary atom, where a SWAP-based leakage detection unit outperforms the standard design. Next, we …
A New Likely Pulsar Binary In 47 Tucanae From Continuum Searches, Thomas Maccarone, Alessandro Paduano, Arash Bahramian, Liliana E. Rivera Sandoval, Jay Strader, James C. A. Miller-Jones, Angiraben D. Mahida, Craig O. Heinke, Laura Chomiuk
A New Likely Pulsar Binary In 47 Tucanae From Continuum Searches, Thomas Maccarone, Alessandro Paduano, Arash Bahramian, Liliana E. Rivera Sandoval, Jay Strader, James C. A. Miller-Jones, Angiraben D. Mahida, Craig O. Heinke, Laura Chomiuk
Physics & Astronomy Faculty Publications
We present evidence that the X-ray source 47 Tuc W41, long considered to be an X-ray source powered by coronal activity, is actually a redback pulsar binary. The source continually shows LX = 3 × 1031 erg s−1 (0.5–10 keV), which is well in excess of the coronal saturation limit for active binaries in quiescence, but is consistent with the intrabinary shock observed in redback pulsars, as is its photon index of Γ = 1.4 ± 0.1. In addition, using deep data from the Australia Telescope Compact Array, we show that W41 is a faint (9.8 ± 1.4μJy …
Measurements And Studies For Rare Event Searches Using Directional Detectors, Elizabeth Tilly
Measurements And Studies For Rare Event Searches Using Directional Detectors, Elizabeth Tilly
Physics & Astronomy ETDs
Measuring topology and initial direction of low-energy (keV-MeV) particle tracks is interesting to rare-event searches. While directional dark matter searches have been one of the largest drivers for R&D for low-energy directional detectors, this work is interested in its application to Migdal searches. The Migdal effect—a nuclear recoil and an electron recoil sharing a vertex—has been used as a detection channel for low-mass dark matter but has only recently been measured. Low-energy directional detectors are ideal to measure the canonic Migdal topology. This dissertation discusses 3D reconstruction algorithms developed for the Migdal In Galactic Dark mAtter expLoration (MIGDAL) experiment and …
Exploring The Role Of A Mushy, Crustal Compliant Region In Volcano Deformation, Grant A. Block
Exploring The Role Of A Mushy, Crustal Compliant Region In Volcano Deformation, Grant A. Block
Physics & Astronomy ETDs
Volcanoes are both creative and destructive forces that have shaped and continue to shape our world from early geologic time to the present day. Continued study of volcanic processes not only better prepares us for monitoring volcanic hazards but also allows us to better understand processes fundamental to Earth as we know it, such as the generation of the atmosphere and accretion of the continents. This dissertation focuses on an integral part of volcanic processes: the trans-crustal magmatic transport system. Specifically, we investigate regions of these transport systems where magma pools in melt-rich lenses within broader regions of low melt-fraction, …
Directed Searches For Gravitational Waves From Ultralight Vector Boson Clouds Around Merger Remnant And Galactic Black Holes During The First Part Of The Fourth Ligo-Virgo-Kagra Observing Run, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang
Directed Searches For Gravitational Waves From Ultralight Vector Boson Clouds Around Merger Remnant And Galactic Black Holes During The First Part Of The Fourth Ligo-Virgo-Kagra Observing Run, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang
Physics & Astronomy Faculty Publications
We present the first directed searches for long-transient and continuous gravitational waves from ultralight vector boson clouds around known black holes (BHs). We use LIGO data from the first part of the fourth LIGO-Virgo-KAGRA observing run. The searches target two distinct types of BHs and use two new semicoherent methods: hidden Markov model (HMM) tracking for the remnant BHs of the mergers GW230814_230901 and GW231123_135430 (referred to as GW230814 and GW231123 in this study) and a dedicated method using the Band Sampled Data (BSD) framework for the galactic BH in the Cygnus X-1 binary system. Without finding evidence of a …
Iron-Decorated Graphene Nanoplatelets Produced By Atmospheric-Pressure Ferrocene Pyrolysis As Nano-Additives For Cement Mortars, Harutyun Gyulasaryan, Manoj Chhetri, Karen S. Martirosyan, Nelli Muradyan, Hovsep Hoveyan, Manuk Barseghyan, Aram Manukyan
Iron-Decorated Graphene Nanoplatelets Produced By Atmospheric-Pressure Ferrocene Pyrolysis As Nano-Additives For Cement Mortars, Harutyun Gyulasaryan, Manoj Chhetri, Karen S. Martirosyan, Nelli Muradyan, Hovsep Hoveyan, Manuk Barseghyan, Aram Manukyan
Physics & Astronomy Faculty Publications
This study examines iron-based graphene nanoplatelets (Fe-GNPs), synthesized through a modified ferrocene pyrolysis route, as hybrid nano-additives for cement mortars. The nanomaterial was characterized by scanning electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller surface area analysis, and thermogravimetric analysis, confirming a graphitic carbon network decorated with crystalline α-Fe nanoparticles. Mortars containing 0.001, 0.01, 0.05, and 0.1 wt.% Fe-GNPs, with and without surfactant-assisted ultrasonication, were tested in flexure and compression after 7 and 28 days of curing. The results showed a clear concentration-dependent response, with 0.01 wt.% yielding the highest strength gains. At 28 days, this dosage increased flexural strength by 14.5% without …
Search For Planetary-Mass Ultracompact Binaries Using Data From The First Part Of The Ligo–Virgo–Kagra Fourth Observing Run, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang
Search For Planetary-Mass Ultracompact Binaries Using Data From The First Part Of The Ligo–Virgo–Kagra Fourth Observing Run, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang
Physics & Astronomy Faculty Publications
We present a search for gravitational waves from inspiraling, planetary-mass ultracompact binaries using data from the first part of the fourth observing run of LIGO, Virgo, and KAGRA. Finding no evidence of such systems, we determine the maximum distance reach for such objects and their merger rate densities. Then, we identify classes of primordial black hole mass distributions for which these rate limits can be translated into relevant constraints on the mass distribution of primordial black holes, assuming that they are all composed of dark matter, in the mass range [10−6,10−3]𝑀⊙. Our constraints for the class of primordial black hole …
Out Of This World: An Exoplanetary Workshop, Monica Storss, Bart Kuipers
Out Of This World: An Exoplanetary Workshop, Monica Storss, Bart Kuipers
ELO (un)supervised 2026
The workshop investigates how scientific constraints can productively defamiliarize human experience and create new frameworks for creativity and expression. Participants will produce original work while considering broader questions about environment, perception, and cultural formation in speculative contexts, and how the arts, sciences, and technology inform each other in relational multiplicities. This generative workshop explores how astronomical data from confirmed exoplanets can generate new poetic forms and linguistic constraints. Participants will examine how exoplanetary conditions can shape language, metaphor, and narrative structure. We'll develop from writing exercises that respond to non-terrestrial physical parameters: alternative light spectra, gravitational variations, and atmospheric compositions. …
Scattered Light Noise At Ligo Livingston Observatory Induced By Microseismic Ground Motion, Debasmita Nandi
Scattered Light Noise At Ligo Livingston Observatory Induced By Microseismic Ground Motion, Debasmita Nandi
LSU Doctoral Dissertations
Gravitational waves are “ripples” in the fabric of spacetime and create a minuscule change in the distance between two points. After publishing his theory of general relativity in 1915, Albert Einstein predicted the existence of gravitational waves as a consequence of the theory. Almost 100 years after the theoretical prediction, gravitational waves were detected for the first time in 2015 by the Advanced LIGO detectors in Livingston, Louisiana, and Hanford, Washington. Gravitational waves have a very small amplitude, making it very challenging to detect them. Different types of noise sources either of instrumental or environmental origin can reduce the astrophysical …
Gwtc-4.0: Population Properties Of Merging Compact Binaries, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Wenhui Wang
Gwtc-4.0: Population Properties Of Merging Compact Binaries, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Wenhui Wang
Physics & Astronomy Faculty Publications
We detail the population properties of binary neutron star, neutron star–black hole binary, and binary black hole mergers using 158 events from the cumulative Gravitational-Wave Transient Catalog 4.0. The black hole primary mass distribution consists of a power-law-like continuum that steepens above 35 M⊙ with overdensities at 10 M⊙ and 35 M⊙. Binary black holes with primary masses near 10 M⊙ are more likely to have less massive secondaries, with a mass ratio distribution peaking at q=0.74+0.13−0.13, potentially a signature of stable mass transfer during binary evolution. Black hole spins are inferred to be nonextremal, with …
Narrowband Searches For Continuous Gravitational Waves From Known Pulsars In The First Two Parts Of The Fourth Ligo–Virgo–Kagra Observing Run, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Miriam Ramos Arevalo, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang
Narrowband Searches For Continuous Gravitational Waves From Known Pulsars In The First Two Parts Of The Fourth Ligo–Virgo–Kagra Observing Run, A. G. Abac, I. Abouelfettouh, Teviet Creighton, Mario C. Diaz, Raul Alberto Espinosa Perez, J. Lawrence, Francisco Llamas Villarreal, Miriam Ramos Arevalo, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang
Physics & Astronomy Faculty Publications
Rotating nonaxisymmetric neutron stars (NSs) are promising sources for continuous gravitational waves (CWs). CWs may, if detected, inform us about the internal structure and equation of state of NSs. Here, we present a narrowband search for CWs from known pulsars, for which a matched-filter search can be applied. Narrowband searches are robust to mismatches between electromagnetic (EM) and gravitational emissions, in contrast to fully targeted searches where they are assumed to be phase-locked. In this work, we search for the CW counterparts emitted by 34 pulsars using data from the first and second parts of the fourth LIGO–Virgo–KAGRA observing run. …
Jwst-Tst High Contrast: First Direct Spectroscopy Of Gj 504 B Reveals Clouds And Possible Metal Enrichment, Aneesh Baburaj, Jean-Baptiste Ruffio, Marshall Perrin Perrin, Jerry W. Xuan, William O. Balmer, Yayaati Chachan, Quinn M. Konopacky, Travis S. Barman, Mathilde Mâlin, Kielan K.W. Hoch, Emily Rickman, K. Ward-Duong, Laurent Pueyo, Julien H. Girard, Isabel Rebollido, Nikole K. Lewis, Jeff Valenti, Sara Seager, Chris Stark, Rémi Soummer, Jay Anderson, Charles-Philippe Lajoie, Mark Clampin, C. Matt Mountain
Jwst-Tst High Contrast: First Direct Spectroscopy Of Gj 504 B Reveals Clouds And Possible Metal Enrichment, Aneesh Baburaj, Jean-Baptiste Ruffio, Marshall Perrin Perrin, Jerry W. Xuan, William O. Balmer, Yayaati Chachan, Quinn M. Konopacky, Travis S. Barman, Mathilde Mâlin, Kielan K.W. Hoch, Emily Rickman, K. Ward-Duong, Laurent Pueyo, Julien H. Girard, Isabel Rebollido, Nikole K. Lewis, Jeff Valenti, Sara Seager, Chris Stark, Rémi Soummer, Jay Anderson, Charles-Philippe Lajoie, Mark Clampin, C. Matt Mountain
Astronomy: Faculty Publications
Characterizing the coldest directly imaged companions through direct spectroscopy has only recently become possible with the James Webb Space Telescope. We present moderate-resolution (R ∼ 2700) spectroscopic observations of the directly imaged planetary-mass companion (PMC), GJ 504 b, using the JWST/NIRSpec. The coldest imaged PMC of the pre-JWST era GJ 504 b is too faint for ground-based spectroscopy, with only photometric observations possible. Leveraging advanced postprocessing techniques with a forward-modeling framework, we detect the companion at high signal-to-noise (S/N > 300). We also present the first successful point-spread function (PSF) subtraction with angular differential imaging (ADI) in the NIRSpec point …
Prediction Of Satellite Temperature During An Orbit Of A Cubesat, Michael Reynolds
Prediction Of Satellite Temperature During An Orbit Of A Cubesat, Michael Reynolds
Honors Theses
This thesis develops a thermal-simulation strategy for predicting CubeSat component temperatures, applied to Jag-Sat-1, a CubeSat developed at the University of South Alabama and deployed from the International Space Station in 2022. The orbit was reconstructed from two-line element (TLE) data using simplified general perturbations (SGP4) propagation, and spacecraft attitude was recovered from onboard gyroscope measurements. Sunlight, penumbra, and umbra intervals were computed geometrically, and the external radiative environment — direct solar, Earth infrared, and albedo heat fluxes — was modeled using orientation-dependent view factors. These time-varying fluxes drove a transient finite-element thermal simulation of the full satellite geometry in …