Astrophysics and Astronomy Commons^™

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 …

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 …

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, …

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 …

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 …

Optically Targeted Search For Gravitational Waves Emitted By Core-Collapse Supernovae During The Third Observing Run Of Advanced Ligo And Advanced Virgo, Marek J. Szczepańczyk, Yanyan Zheng, Javier M. Antelis, Michael G. Benjamin, Marie-Anne Bizouard, Alejandro Casallas-Lagos, Pablo Cerda-Duran, Derek Davis, Dorota Gondek-Rosinska, Soma Mukherjee

Physics & Astronomy Faculty Publications

We present the results from a search for gravitational-wave transients associated with core-collapse supernovae observed optically within 30 Mpc during the third observing run of Advanced LIGO and Advanced Virgo. No gravitational wave associated with a core-collapse supernova has been identified. We then report the detection efficiency for a variety of possible gravitational-wave emissions. For neutrino-driven explosions, the distance at which we reach 50% detection efficiency is up to 8.9 kpc, while more energetic magnetorotationally driven explosions are detectable at larger distances. The distance reaches for selected models of the black hole formation, and quantum chromodynamics phase transition are also …

Cosmic Variance Of The Hellings And Downs Correlation For Ensembles Of Universes Having Nonzero Angular Power Spectra, Deepali Agarwal, Joseph D. Romano

Physics & Astronomy Faculty Publications

Gravitational waves (GWs) induce correlated perturbations to the arrival times of pulses from an array of galactic millisecond pulsars. The expected correlations, obtained by averaging over many pairs of pulsars having the same angular separation (pulsar averaging) and over an ensemble of model universes (ensemble averaging), are described by the Hellings and Downs curve. As shown by Allen [Phys. Rev. D 107, 043018 (2023)], the pulsar-averaged correlation will not agree exactly with the expected Hellings and Downs prediction if the gravitational-wave sources interfere with one another, differing instead by a “cosmic variance” contribution. The …

On The Formation And Detectability Of H2Cncn And Its Progenitors, Ryan C. Fortenberry, Vincent J. Esposito

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

New highly exothermic formation pathways incorporating both thermodynamic and kinetic control for the newly astronomically detected H₂CNCN molecule are paired with extremely accurate quantum chemical rovibrational spectroscopic computations. The reactions between astronomically known CH₂CN/CH₂CCH + HNCN follow effectively identical pathways and proceed through stable intermediates and over deeply submerged transition states to form H₂CNCN and HCN/HCCH coproducts. Similarly, the reaction between CHM₂CN and NCN⁻ can also form H₂CNCN, although this pathway first requires the initial formation of NCN⁻, which is currently undetected in space, via …

Ultralight Vector Dark Matter Search Using Data From The Kagra O3gk Run, A. Abac, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the …

Mhongoose: A Meerkat Nearby Galaxy H I Survey, Stacy S. Mcgaugh

Faculty Scholarship

The MHONGOOSE (MeerKAT H i Observations of Nearby Galactic Objects: Observing Southern Emitters) survey maps the distribution and kinematics of the neutral atomic hydrogen (H i) gas in and around 30 nearby star-forming spiral and dwarf galaxies to extremely low H i column densities. The H i column density sensitivity (3σ over 16 km s−1) ranges from ∼5 × 1017 cm−2 at 9000 resolution to ∼4 × 1019 cm−2 at the highest resolution of 700. The H i mass sensitivity (3σ over 50 km s−1) is ∼5.5×105 M at a distance of 10 Mpc (the median distance of the sample …

Experimental Determination Of The Unusual Ch Stretch Frequency Of Protonated Fullerenes, Laura Finazzi, Vincent J. Esposito, Julianna Palotás, Jonathan Martens, Els Peeters, Jan Cami, Giel Berden, Jos Oomens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report experimental values for the CH stretch frequencies of the protonated fullerenes C₆₀H⁺ and C₇₀H⁺. Anharmonic frequency calculations at the B3LYP/6-31G level of theory, which are independent of empirical scaling factors, reproduce the experimental values to within approximately 5 cm⁻¹. Scaling theoretical harmonic frequencies by applying factors derived for polycyclic aromatic hydrocarbons deviate significantly from the experimentally measured frequency. We attribute this deviation to the unusual hydrocarbon structure that affects the degree of anharmonicity of the CH stretch. This result allows us to propose an original, specific scaling factor of …

Archaeology In Space: The Sampling Quadrangle Assemblages Research Experiment (Square) On The International Space Station. Report 1: Squares 03 And 05, Justin St. P. Walsh, Shawn Graham, Alice C. Gorman, Chantal Brousseau, Salma Abdullah

Art Faculty Articles and Research

Between January and March 2022, crew aboard the International Space Station (ISS) performed the first archaeological fieldwork in space, the Sampling Quadrangle Assemblages Research Experiment (SQuARE). The experiment aimed to: (1) develop a new understanding of how humans adapt to life in an environmental context for which we are not evolutionarily adapted, using evidence from the observation of material culture; (2) identify disjunctions between planned and actual usage of facilities on a space station; (3) develop and test techniques that enable archaeological research at a distance; and (4) demonstrate the relevance of social science methods and perspectives for improving life …

A Review Of Stable, Traversable Wormholes In F(R) Gravity Theories, Ramesh Radhakrishnan, Patrick Brown, Jacob Matulevich, Eric Davis, Delaram Mirfendereski, Gerald Cleaver

Physics & Astronomy Faculty Publications

It has been proven that in standard Einstein gravity, exotic matter (i.e., matter violating the pointwise and averaged Weak and Null Energy Conditions) is required to stabilize traversable wormholes. Quantum field theory permits these violations due to the quantum coherent effects found in any quantum field. Even reasonable classical scalar fields violate the energy conditions. In the case of the Casimir effect and squeezed vacuum states, these violations have been experimentally proven. It is advantageous to investigate methods to minimize the use of exotic matter. One such area of interest is extended theories of Einstein gravity. It has been claimed …

Let There Be Light, Erik Johnson

Natural Science Faculty

On May 10, Earth experienced the greatest solar storm in decades. When scientists predicted a high chance for auroras, also known as the northern lights, observers around the world traveled away from light-polluted cities to look for them.

Prospects For Time-Domain And Multi-Messenger Science With Axis, Riccardo Arcodia, Franz E. Bauer, S. Bradley Cenko, Kristen C. Dage, Daryl Haggard, Wynn C.G. Ho, Erin Kara, Michael Koss, Tingting Liu, Labani Mallick, Michela Negro, Pragati Pradhan, J. Quirola-Vásquez, Mark T. Reynolds, Claudio Ricci, Richard E. Rothschild, Navin Sridhar, Eleonora Troja, Yuhan Yao

Publications

The Advanced X-ray Imaging Satellite (AXIS) promises revolutionary science in the X-ray and multi-messenger time domain. AXIS will leverage excellent spatial resolution (< 1.5 arcsec), sensitivity (80× that of Swift), and a large collecting area (5–10× that of Chandra) across a 24-arcmin diameter field of view at soft X-ray energies (0.3–10.0 keV) to discover and characterize a wide range of X-ray transients from supernova-shock breakouts to tidal disruption events to highly variable supermassive black holes. The observatory’s ability to localize and monitor faint X-ray sources opens up new opportunities to hunt for counterparts to distant binary neutron star mergers, fast radio bursts, and exotic phenomena like fast X-ray transients. AXIS will offer a response time of < 2 h to community alerts, enabling studies of gravitational wave sources, high-energy neutrino emitters, X-ray binaries, magnetars, and other targets of opportunity. This white paper highlights some of the discovery science that will be driven by AXIS in this burgeoning field of time domain and multi-messenger astrophysics. This White Paper is part of a series commissioned for the AXIS Probe Concept Mission; additional AXIS White Papers can be found at the AXIS website.

Analyzing Hubble Space Telescope Images Of Agn Host Galaxies With Keck Integral Field Spectra, Sebastian Contreras

Physics

In the center of most massive galaxies is a supermassive black hole (SMBH) with a mass that can range from millions to billions of solar masses. It has been observed that more massive SMBHs have a more massive host galaxy bulge, as evidenced by the larger bulge luminosity and stellar velocity dispersion, a correlation known as the BH mass - host-galaxy scaling relation. It suggests a close evolutionary connection between the growth of the SMBH and the growth of its host galaxy. If a SMBH develops an accretion disk to fuel an active galactic nucleus (AGN), it will emit radiation …

Jwst-Tst High Contrast: Jwst/Nircam Observations Of The Young Giant Planet Β Pic B, Jens Kammerer, Kellen Lawson, Marshall D. Perrin, Isabel Rebollido, Christopher C. Stark, Tomas Stolker, Julien H. Girard, Laurent Pueyo, William O. Balmer, Kadin Worthen, Christine Chen, Roeland P. Van Der Marel, Nikole K. Lewis, Kimberly Ward-Duong, Jeff A. Valenti, Mark Clampin, C. Matt Mountain

Astronomy: Faculty Publications

We present the first JWST/NIRCam observations of the directly imaged gas giant exoplanet β Pic b. Observations in six filters using NIRCam's round coronagraphic masks provide a high-signal-to-noise-ratio detection of β Pic b and the archetypal debris disk around β Pic over a wavelength range of ∼1.7-5 μm. This paper focuses on the detection of β Pic b and other potential point sources in the NIRCam data, following a paper by Rebollido et al. that presented the NIRCam and MIRI view of the debris disk around β Pic. We develop and validate approaches to obtaining accurate photometry of planets in …

Microwave Spectroscopy And Large Amplitude Motion Of Chlorosulfonic Acid (Clso2oh), Aaron J. Reynolds, Diego E. Rodriguez, Wei Lin, Kenneth R. Leopold

Physics & Astronomy Faculty Publications

The high-resolution rotational spectrum of chlorosulfonic acid (ClSO2OH) has been studied using both broadband and cavity-based Fourier transform microwave spectrometers over the frequency range of 5–18 GHz. a-, b-, and c-type transitions have been recorded for both the 35Cl and 37Cl isotopologues. The observation of c-type lines establishes that the molecule lacks a plane of symmetry and suggests that the OH group can undergo large amplitude motion between equivalent structures. Interconversion between these structures can be achieved via internal rotation through two inequivalent barriers occurring at Cl-S-O-H torsional angles of 0 or 180 degrees. As in …