Astrophysics and Astronomy Commons^™

A Class Of Stable Nonlinear Non-Hermitian Skin Modes, Hamed Ghaemi-Dizicheh

Physics & Astronomy Faculty Publications

The non-Hermitian skin effect (NHSE) is a well-known phenomenon in open topological systems that causes a large number of eigenstates to become localized at the boundary. Although many aspects of its theory have been investigated in linear systems, this phenomenon remains novel in nonlinear models. In the first step of this paper, we look at the conditions for the presence of quasi-skin modes in a semi-infinite, one-dimensional, nonlinear, nonreciprocal lattice. In the following phase, we explore the survival time of the quasi-skin mode in a finite nonlinear lattice with open edges. We study the dependency of the survival time on …

Statistical Methods For Interpreting Spatial And Temporal Heterogeneity Of Martian Tropical Water Ice Informed By Properties Of Crater Ejecta Types, Jamie D. Riggs, Michelle R. Kirchoff

College of Population Health Faculty Papers

The martian tropical water ice spatial and temporal distribution was characterized using impact crater ejecta type, location, size, and age in one of two epochs, (Formula presented.) Ga and (Formula presented.) Ga, using statistical models designed for spatial and temporal correlation structures. The indicator thought to identify the presence of ice is craters with layered ejecta, while the indicator thought to identify no ice is craters with radial ejecta. These indicators imply the location (longitude and latitude) and, potentially, depth (crater diameter as a proxy) of ice, and when the ice was present. The spatial and temporal distribution of layered …

Battle Of The Ch Motions: Aliphatic Vs Aromatic Contributions To Astronomical Pah Emission And Exploration Of The Aliphatic, Aromatic, And Ethynyl Ch Stretches, Vincent J. Esposito, Salma Bejaoui, Brant E. Billinghurst, Christiaan Boersma, Ryan C. Fortenberry, Farid Salama

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Strong anharmonic coupling between vibrational states in polycyclic aromatic hydrocarbons (PAH) produces highly mixed vibrational transitions that challenge the current understanding of the nature of the astronomical mid-infrared PAH emission bands. Traditionally, PAH emission bands have been characterized as either aromatic or aliphatic, and this assignment is used to determine the fraction of aliphatic carbon in astronomical sources. In reality, each of the transitions previously utilized for such an attribution is highly mixed with contributions from both aliphatic and aromatic CH motions as well as non-CH motions such as CC stretches. High-resolution gas-phase IR absorption measurements of the spectra of …

Accelerated Structure Formation: The Early Emergence Of Massive Galaxies And Clusters Of Galaxies, Stacy S. Mcgaugh

Faculty Scholarship

Galaxies in the early Universe appear to have grown too big too fast, assembling into massive, monolithic objects more rapidly than anticipated in the hierarchical Lambda cold dark matter (ΛCDM) structure formation paradigm. The available photometric data are consistent with there being a population of massive galaxies that form early (z ≳ 10) and quench rapidly over a short (≲1 Gyr) timescale, consistent with the traditional picture for the evolution of giant elliptical galaxies. Similarly, kinematic observations as a function of redshift show that massive spirals and their scaling relations were in place at early times. Explaining the early emergence …

Constraining Accreted Neutron Star Crust Shallow Heating With The Inferred Depth Of Carbon Ignition In X-Ray Superbursts, Zachary P. Meisel

Faculty Publications

Evidence has accumulated for an as-yet unaccounted for source of heat located at shallow depths within the accreted neutron star crust. However, the nature of this heat source is unknown. I demonstrate that the inferred depth of carbon ignition in X-ray superbursts can be used as an additional constraint for the magnitude and depth of shallow heating. The inferred shallow heating properties are relatively insensitive to the assumed crust composition and carbon fusion reaction rate. For low-accretion rates, the results are weakly dependent on the duration of the accretion outburst, so long as accretion has ensued for enough time to …

Blazing Trails, Erik Johnson

Natural Science Faculty

Comets have always captivated people. Some cultures saw the appearance of comets as omens and some have hypothesized that a comet served as the Star of Bethlehem from the Nativity story.

Exploring The Structure Of Space Science Research In Mexico Using Science Mapping Tool: Citespace., Ibis Anette Moreno-Lozano, Humberto Carrillo-Calvet, Jose Luis Jiménez-Andrade, Ricardo Arencibia-Jorge

UTA Libraries Staff Publications - Archive

This paper presents an analysis of the knowledge structure of the Mexican scientific community in the field of Space Science in Web of Science, between 2000 and 2019. CiteSpace software helped to identify the influential papers in the domain. The findings of this study shed light on the historical development of Space Science in Mexico and highlight the country's scientific performance with the worldwide trend. Moreover, the study emphasized the importance of bibliometrics in understanding the scientific undercurrents of a discipline. By analyzing co-citation networks, the study identified prominent clusters and research fronts in the field, providing valuable insights into …

Exploring Black Hole Entropy, Spacetime Perturbations, And Their Applications In Astrophysics, Ashley Meglino

PANDION: The Osprey Journal of Research and Ideas

Abstract

Tidal deformations and quasinormal frequencies result when a black hole experiences a perturbation to its geometry, such as by a small mass or a field. These effects can be measured experimentally from gravitational wave data or calculated mathematically using various methods. This paper details various studies that were done to develop meaningful and accurate calculations of tidal Love numbers and quasinormal frequencies, as well as the motivations for such efforts. In addition, various attempts to formulate a more sound interpretation of black hole entropy are discussed, including the shortcomings of some and the significance of these efforts in other …

Validating Irregular Metallicities In Galactic Center Stars, Kiyah Young-Wilson, Joshua Shields

CURCI Student Research

In the summer of 2024, I participated in research under Dr. Wolfgang Kerzendorf, a professor at Michigan State University, and Dr. Joshua Shields, a postdoctoral researcher who works with Dr. Kerzendorf. Dr. Shields developed the open-source code STARDIS, which used photosphere models from databases such as MARCS to generate stellar spectra; within STARDIS, the elemental abundance of these stars can be adjusted. My objective was to use STARDIS to adjust generated spectra and compare the results to observed absorption spectrum from Galactic Center Stars to verify if certain stars contained an abnormal amount of certain heavy elements, such as Scandium. …

Exploring Machine Learning, Feature Engineering, And Explainability To Constrain Spica’S Apsidal Constant Through Mesa Simulations, Hannah C. Woodruff

Doctoral Dissertations and Master's Theses

Spica (α-Virginis) is a notable binary star system located in the constellation of Virgo and offers valuable insights into stellar interiors and dynamics. Within binary systems, gravitational forces between the two stars cause minor distortions that alter their orbital motion. The steady rate of this alteration is known as the apsidal constant, which provides key information about a star’s internal structure and its evolutionary state. Traditionally, stellar environments like Spica are studied using simulations, such as MESA (Modules for Experiments in Stellar Astrophysics). These simulations allow researchers to explore various aspects of stellar behavior through the entire evolution of the …

Computational And Experimental Data For Undoped And Er-Doped Lithium Tantalate Nanofluorescent Probes, Mkhitar A. Hobosyan, Andrea Pelayo Carvajal, Bhupendra B. Srivastava, Tamanna Zakia, Mohammed Jasim Uddin, Karen S. Martirosyan, Eric Rodriguez, Kofi Nketia Ackaah-Gyasi, Nicholas Dimakis

Physics & Astronomy Faculty Publications

The density functional theory (DFT) and experimental data presented in this paper refer to the research article “Computational and experimental study on undoped and Er-doped lithium tantalate nano fluorescent probes”. The DFT data contain electronic and optical properties for both LiTaO3 and LiTaO3:Er+3, with Er+3 occupying either Li or Ta sites at 4.167 mol. %. All these properties were calculated at the generalized gradient approximation (GGA) limit. Additionally, electronic information was calculated using the hybrid functional by Heyd, Scuseria, and Ernzerho (HSE06), which accurately predicts the location in energy for all Er-4f orbitals. We also include simulated X-ray near edge …

Search For Eccentric Black Hole Coalescences During The Third Observing Run Of Ligo And Virgo, A. G. Abac, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas Villarreal, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on …

Mhongoose Discovery Of A Gas-Rich Low Surface Brightness Galaxy In The Dorado Group, Stacy Mcgaugh

Faculty Scholarship

We present the discovery of a low-mass, gas-rich low surface brightness galaxy in the Dorado group, at a distance of 17.7 Mpc. Combining deep MeerKAT 21-cm observations from the MeerKAT Hi Observations of Nearby Galactic Objects: Observing Southern Emitters (MHONGOOSE) survey with deep photometric images from the VST Early-type Galaxy Survey (VEGAS) we find a stellar and neutral atomic hydrogen (H i) gas mass of M∗ = 2:23 × 106M⊙ and MHI = 1:68 × 106 M⊙, respectively. This low surface brightness galaxy is the lowest-mass Hi detection found in a group beyond the local Universe (D ≳ 10 Mpc). …

The First Joint Observation By Kagra With Geo 600, N. Uchikata, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

KAGRA conducted its first joint observation with GEO 600 for two weeks in April, 2020. We performed two types of all-sky searches and two searches dedicated to gravitational wave signals associated with gamma-ray burst events observed during the run. We did not detect any gravitational wave signals, which was expected given the sensitivity of both detectors at that time. However, we did confirm that several search pipelines used in the LIGO-Virgo-KAGRA collaborations worked effectively on the KAGRA data. In this presentation we will report on the data quality of detectors and the search results.

Search For Core Collapse Supernovae Signals In Ligo’S Third Observation Run Using A Network Of Gravitational Wave Detectors Integrated With A Multiclass Convolutional Neural Network, Shahrear Khan Faisal, Gaukhar Nurbek, Michael Benjamin, Bhawana Sedhai, Soma Mukherjee

Physics & Astronomy Faculty Publications

In the existing body of literature, numerous waveforms of core collapse supernovae (CCSN) have emerged from extensive simulations conducted in high-performance computing facilities globally. These waveforms exhibit distinct characteristics related to their explosion mechanisms, influenced by parameters such as progenitor mass, angular momentum, gravitational wave energy, peak frequency, duration, and equation of state. Core collapse supernovae stand out as highly anticipated sources in LIGO’s fourth observation (O4) run, prompting dedicated efforts to detect them. The integration of machine learning, specifically convolutional neural networks (CNN), has become a pivotal avenue for analysis. This study addresses a fundamental query: how can a …

Exploring The Early Solar System: Cometary Chemical Fingerprints: A Study Of Comet C/2022 E3 (Ztf) Via Near-Infrared Spectroscopy, Grace Puchalski

Undergraduate Research Symposium

Comets are small, icy remnants from the solar system formation (4.5 billion years ago). Their interior composition should reflect the composition and conditions presented in the mid-plane of the protoplanetary region where (and when) they formed. These small objects predominantly reside in two major reservoirs, the Oort cloud and the Kuiper belt. Comets coming from the Oort cloud have long orbital periods while comets from the Kuiper belt have short orbital periods (< 200 years). An overarching goal in astronomy is to understand the conditions presented in the planetary region in the early solar system. Since comets lack a known mechanism of self internal heating, any processes that have changed their composition should only affect a few meters deep, which is believed to be excavated over a course of a perihelion passage into the inner parts of the solar system. As comets get closer to the Sun, solar irradiation causes their ices to sublime, leaving a formation of a freely expanding atmosphere (coma). Depending on the science interest, astrophysicists use different techniques for data collection, a common one being spectroscopy. Using iSHELL spectrograph at the NASA-Near-Infrared Telescope Facility (IRTF), we examine the primary chemical composition (e.g., H2O, CO, CH4, C2H6, C2H2, H2CO, NH3, CH3OH, OCS, and OH) of cometary coma in bright comet C/2022 E3 (ZTF). Our preliminary results indicate the H2O production rate of ~3.4E28 (molecules per second), which corresponds to the rotational temperature of 86 (K). Cometary atmospheres are dense enough that molecules in the inner coma are thermalized by collision (Local Thermodynamic Equilibrium), thus 86 (K) is a physical parameter of coma. We compared the production of the rest of species with that of water (in %) and our results indicated that comet E3 was typical (close to average) in mixing ratios of all volatile species. By mapping the intensity of light with distance from the nucleus,we were able to examine the spatial distribution of volatiles and dust in E3’s coma which were consistent with production directly from the nucleus.

A Systematic Study Of Planetary Envelope Growth With 3d Radiation-Hydrodynamics Simulations, Avery Bailey, James M. Stone, Jeffrey Fung

Physics & Astronomy Faculty Research

In the core accretion model of planet formation, envelope cooling regulates the accretion of material and ultimately sets the time-scale to form a giant planet. Given the diversity of planet-forming environments, opacity uncertainties, and the advective transport of energy by three-dimensional (3D) recycling flows, it is unclear whether one-dimensional models can adequately describe envelope structure and accretion in all regimes. Even in 3D models, it is unclear whether approximate radiative transfer methods sufficiently model envelope cooling, particularly at the planetary photosphere. To address these uncertainties, we present a suite of 3D radiation-hydrodynamics simulations employing methods that directly solve the transfer …

Striatal Beat Frequency Interval Timing Model With Microgravity Stressor, Jason Michael Fitzgerald, Sorinel Oprisan

Journal of the South Carolina Academy of Science

The Striatal Beat Frequency (SBF) model of interval timing uses frontal cortex (FC) neural oscillations to record the state of the brain at the reinforcement time Tc during fixed interval (FI) procedures in the long-term memory (LMEM). The state of the FC oscillators at any given time is stored in a short-term memory (SMEM) buffer. The SBF model uses the spiny neurons of the basal ganglia (BG) as coincidence detectors to produce beats between the content of the SMEM and LMEM. Across multiple species that can perform interval timing, there are two invariant properties: (a) the timing is precise, and …

Birds Of A Feather: Resolving Stellar Mass Assembly With Jwst/Nircam In A Pair Of Kindred Z ∼ 2 Dusty Star-Forming Galaxies Lensed By The Plck G165.7+67.0 Cluster, Patrick S. Kamieneski, Brenda L. Frye, Rogier A. Windhorst, Kevin C. Harrington, Min S. Yun, Allison Noble, Massimo Pascale, Nicholas Foo, Seth H. Cohen, Rolf A. Jansen, Timothy Carleton, Anton M. Koekemoer, Christopher N.A. Willmer, Jake S. Summers, Nikhil Garuda, Reagen Leimbach, Benne W. Holwerda, Justin D.R. Pierel, Eric F. Jiménez-Andrade, S. P. Willner, Belén Alcalde Pampliega, Amit Vishwas, William C. Keel, Q. Daniel Wang, Cheng Cheng, Dan Coe, Christopher J. Conselice, Jordan C.J. D’Silva, Simon P. Driver, Norman A. Grogin, Tyler Hinrichs, James D. Lowenthal

Astronomy: Faculty Publications

We present a new parametric lens model for the G165.7+67.0 galaxy cluster, which was discovered with Planck through its bright submillimeter flux, originating from a pair of extraordinary dusty star-forming galaxies (DSFGs) at z ≈ 2.2. Using JWST and interferometric mm/radio observations, we characterize the intrinsic physical properties of the DSFGs, which are separated by only ∼1″ (8 kpc) and a velocity difference ΔV ≲ 600 km s−1 in the source plane, and thus are likely undergoing a major merger. Boasting intrinsic star formation rates SFRIR = 320 ± 70 and 400 ± 80 M ⊙ yr−1, stellar masses of …

Detailed Study Of A Rare Hyperluminous Rotating Disk In An Einstein Ring 10 Billion Years Ago, Daizhong Liu, Natascha M. Förster Schreiber, Kevin C. Harrington, Lilian L. Lee, Patrick S. Kamieneski, Richard I. Davies, Dieter Lutz, Alvio Renzini, Stijn Wuyts, Linda J. Tacconi, Reinhard Genzel, Andreas Burkert, Rodrigo Herrera-Camus, Belén Alcalde Pampliega, Amit Vishwas, Melanie Kaasinen, Q. Daniel Wang, Eric F. Jiménez-Andrade, James Lowenthal, Nicholas Foo, Brenda L. Frye, Jinyi Shangguan, Yixian Cao, Guido Agapito, Alex Agudo Berbel, Capucine Barfety, Andrea Baruffolo, Derek Berman, Martin Black, Marco Bonaglia, Runa Briguglio, Luca Carbonaro

Astronomy: Faculty Publications

Hyperluminous infrared galaxies (HyLIRGs) are the rarest and most extreme starbursts and found only in the distant Universe (z ≳ 1). They have intrinsic infrared (IR) luminosities LIR ≥ 1013 L⊙ and are commonly found to be major mergers. Recently, the Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts project (PASSAGES) searched ~104 deg2 of the sky and found ~20 HyLIRGs. We describe a detailed study of PJ0116-24, the brightest (μLIR ≈ 2.6 × 1014 L⊙, magnified with μ ≈ 17) Einstein-ring HyLIRG in the southern sky, at z = 2.125, with observations from the near-IR integral-field spectrograph VLT/ERIS and …