Astrophysics and Astronomy Commons^™

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 …

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 …

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 …

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 …

K2-399 B Is Not A Planet, J. Lillo-Box, D. W. Latham, K. A. Collins, D. J. Armstrong, D. Gandolfi, Eric L.N. Jensen, A. Castro-González, O. Balsalobre-Ruza, B. Montesinos, S. G. Sousa, J. Aceituno, R. P. Schwarz, N. Narita, A. Fukui, J. Cabrera, A. Hadjigeorghiou, M. Kuzuhara, T. Hirano, M. Fridlund, A. P. Hatzes, O. Barragán, N. M. Batalha

Physics & Astronomy Faculty Works

Context. The transit technique has been very efficient over the past decades in detecting planet-candidate signals. The so-called statistical validation approach has become a popular way of verifying a candidate’s planetary nature. However, the incomplete consideration of false-positive scenarios and data quality can lead to misinterpretation of the results. Aims. In this work, we revise the planetary status of K2-399 b, a validated planet with an estimated false-positive probability of 0.078% located in the middle of the so-called Neptunian desert, and hence a potential key target for atmospheric prospects. Methods. We used radial velocity data from the …

Value Creation In A Pedagogically-Focused Faculty Online Learning Community, Fred Goldberg, Edward Price, Mo Basir, Lawrence Escalada, Steve Maier, Steven Sahyun, Tamara D. Snyder, Liang Zeng

Physics & Astronomy Faculty Publications

Faculty online learning communities (FOLCs) can help faculty effectively adopt and persist in using research-based curricula. This paper documents faculty perspectives on the value they gained from participating in a multi-year FOLC designed to help them implement an inquiry-based physical science curriculum. Personal value narratives were collected from 11 volunteer FOLC participants. In the narratives, participants responded to prompts regarding their initial reasons for participation, activities they engaged in, and values they gained, as well as how participation impacted their profession, social connections, professional practice, and ability to influence their world as teachers. Qualitative analysis shows that the values faculty …

From Stars To Moons: Investigating Stellar Rotations, Planetary Interactions, And Exoplanetary Prospects, Rosario Cecilio-Flores-Elie

Dissertations, Theses, and Capstone Projects

The thesis is divided into two key sections. The first chapter presents the results of analyzing TESS light curves for 99 targets within the Carina-Near moving group. By deriving rotational periods, this analysis supports stellar age estimation, contributing to the broader efforts of the Backyard Worlds: Planet 9 citizen project in determining age parameters for 89 newly identified systems, including ultracool dwarf companions. These findings enhance our understanding of stellar rotation and evolution, offering new insights into the development of secondary co-moving objects like brown dwarfs.

The second chapter investigates planet-moon interactions within our solar system by examining mass ratios, …

Pulsey: Stellar Pulsation Models In Python, Andrew Ayala

Dissertations, Theses, and Capstone Projects

The era of the Kepler/K2 and TESS space-telescope missions has inundated the astrophysics community with photometric data for millions of stars with continuous observation and very high cadence. This data confirms that nearly every observed stellar source exhibits an oscillating luminosity, with stellar pulsation being the driving mechanism behind a large fraction of the cause. The result has been an explosion in the field of asteroseismology, where the recorded luminosity variations, or "light curves", of pulsating stars to probe their interior structures. By modeling observed light curves, we can constrain values of the physical stellar parameters producing them. The brightness …

A Machine Learning Approach To Discovering Physical Models Of Galaxy Formation, Festa Bucinca

Dissertations, Theses, and Capstone Projects

Galaxies are the breathtakingly beautiful starry islands of the Universe. The process of galaxy formation involves the transformation from simple initial conditions in the early Universe to the complex galaxy structures we observe today. Spanning an immense spatial range and tremendous time scales - from the vastness of the Universe to the scale of individual stars - the physics of galaxy formation is both complex and crucial for understanding the Universe we live in. However, despite significant advancements, our theoretical understanding of galaxy formation remains incomplete.

In the era of big data available from hydrodynamical simulations and observations, Machine Learning …

Active Galactic Nuclei - The Arrhythmic Beat Of A Galactic Heart, Henry James Best V

Dissertations, Theses, and Capstone Projects

Active Galactic Nuclei (AGN) are generally believed to be supermassive black holes (SMBHs) at the center of galaxies which are actively accreting material from the host galaxy. Through this process, they emit radiation across the electromagnetic spectrum both as a smooth continuum and emission lines. However, there is a great variety of the signals we observe–some faint, some bright, some variable and others steady. The wide array of signals produced by AGN is believed to encode both the geometry and the physics surrounding these SMBHs, making them a valuable target for understanding the high gravity limit, their feedback mechanisms to …

Toi–757 B: An Eccentric Transiting Mini–Neptune On A 17.5–D Orbit, A Alqasim, N Grieves, N M. Rosário, D Gandolfi, J H. Livingston, S Sousa, K A. Collins, J K. Teske, M Fridlund, Ryan J. Oelkers

Physics & Astronomy Faculty Publications

We report the spectroscopic confirmation and fundamental properties of TOI 757 b, a mini Neptune on a 17.5 d orbit transiting a bright star (⁠ mag) discovered by the TESS mission. We acquired high precision radial velocity measurements with the HARPS, ESPRESSO, and PFS spectrographs to confirm the planet detection and determine its mass. We also acquired space borne transit photometry with the CHEOPS space telescope to place stronger constraints on the planet radius, supported with ground based LCOGT photometry. WASP and KELT photometry were used to help constrain the stellar rotation period. We also determined the fundamental parameters of …