Astrophysics and Astronomy Commons^™

Indigenous Astronomy As Told By The Haudenosaunee, Sasha Doxtator

2019 Cohort

Colonization has greatly reduced the extent to which Indigenous astronomy is presently known and shared. Much sky lore has become lost or fragmented, and the connections between stories, night sky observations, and their relevance is not as obvious as it once was. A detrimental spiral has ensued with many Western-trained scientists being reluctant to share sky lore out of fear of being misunderstood, disrespected, and dismissed.

A Likelihood Search For Low-Mass Dark Matter Via Inelastic Scattering In Supercdms, Daniel Jardin

Physics Theses and Dissertations

An abundance of evidence suggests that most of the Universe is composed of nonluminous matter. This "dark matter” is believed to be a new elementary particle and experiments around the world are attempting to directly detect rare collisions with terrestrial detectors.

The properties of dark matter have yet to be identified, thus efforts are ongoing to explore a range of possible masses and interaction cross-sections. For the latter, experiments can increase exposure by scaling up the detector mass and operating for a longer time. To search for dark matter with less mass than a nucleon, new technologies and analysis techniques …

Investigating Fourier Coefficient Relationships Of Cepheid Variable Stars, Forrest Cronin, Siobahn Morgan

Summer Undergraduate Research Program (SURP) Symposium

Cepheid stars are valuable due to their usefulness in determining distances within our galaxy, and to other galaxies. Cepheid stars’ light variation can be parameterized using a Fourier series with coefficients Ai and ��i . Fourier coefficients have been shown to have trends linked to physical characteristics of Cepheids and RR Lyrae stars, such as luminosity, radius, pulsation modes and metallicity. Using data from the OGLE III and IV surveys, we determined relationships between Fourier coefficients in different photometric system and observed the influence of metallicity on the Cepheids in the Small Magellanic Cloud and the Large Magellanic Cloud. The …

The Hubble Space Telescope Pancet Program: Exospheric Mg Ii And Fe Ii In The Near-Ultraviolet Transmission Spectrum Of Wasp-121b Using Jitter Decorrelation, David K. Sing, Panayotis Lavvas, Gilda E. Ballester, Alain Lecavelier Des Etangs, Mark S. Marley, Nikolay Nikolov, Lofti Ben-Jaffel, Vincent Bourrier, Lars A. Buchhave, Drake Deming, David Ehrenreich, Thomas Mikal-Evans, Tiffany Kataria, Nikole K. Lewis, Mercedes López-Morales, Antonio García Muñoz, Gregory W. Henry, Jorge Sanz-Forcada, Jessica J. Spake, Hannah R. Wakeford, The Pancet Collaboration

Information Systems and Engineering Management Research Publications

We present Hubble Space Telescope (HST) near-ultraviolet (NUV) transits of the hot Jupiter WASP-121b, acquired as part of the PanCET program. Time-series spectra during two transit events were used to measure the transmission spectra between 2280 and 3070 Å at a resolution of 30,000. Using HST data from 61 Space Telescope Imaging Spectrograph visits, we show that data from HST's Pointing Control System can be used to decorrelate the instrument systematic errors (jitter decorrelation), which we used to fit the WASP-121b light curves. The NUV spectra show very strong absorption features, with the NUV white light curve found to be …

Formation Of Ultra-Diffuse Galaxies In The Field And In Galaxy Groups, Fangzhou Jiang, Avishai Dekel, Jonathan Freundlich, Aaron Romanowsky, Aaron Dutton, Andrea Macciò, Arianna Di Cintio

Faculty Publications

We study ultra-diffuse galaxies (UDGs) in zoom in cosmological simulations, seeking the origin of UDGs in the field versus galaxy groups. We find that while field UDGs arise from dwarfs in a characteristic mass range by multiple episodes of supernova feedback (Di Cintio et al.), group UDGs may also form by tidal puffing up and they become quiescent by ram-pressure stripping. The field and group UDGs share similar properties, independent of distance from the group centre. Their dark-matter haloes have ordinary spin parameters and centrally dominant dark-matter cores. Their stellar components tend to have a prolate shape with a Sérsic …

Kelt-23ab: A Hot Jupiter Transiting A Near-Solar Twin Close To The Tess And Jwst Continuous Viewing Zones, D. Johns, P. A. Reed, J. E. Rodriguez, J. Pepper, K. A. Stassun, K. Penev, B. S. Gaudi, J. Labadie-Bartz, B. J. Fulton, S. N. Quinn, J. D. Eastman, D. R. Ciardi, L. Hirsch, D. J. Stevens, C. P. Stevens, T. E. Oberst, David H. Cohen, Eric L.N. Jensen, P. Benni, S. Villanueva Jr., G. Murawski, A, Bieryla, D. W. Latham, S. Vanaverbeke, F. Dubois, S. Rau, L. Logie, R. F. Rauenzahn, R. A. Wittenmyer, R. Zambelli, D. Bayliss, T. G. Beatty, K. A. Collins, K. D. Colón, I. A. Curtis, P. Evans, J. Gregorio, D. James, D. L. Depoy, M. C. Johnson, M. D. Joner, D. H. Kasper, S. Khakpash, J. F. Kielkopf, R. B. Kuhn, M. B. Lund, M. Manner, J. L. Marshall, K. K. Mcleod, M. T. Penny, H. Relles, R. J. Siverd, D. C. Stephens, C. Stockdale, T.-G. Tan, M. Trueblood, P. Trueblood, X. Yao

Physics & Astronomy Faculty Works

We announce the discovery of KELT-23Ab, a hot Jupiter transiting the relatively bright (V = 10.3) star BD+66 911 (TYC 4187-996-1), and characterize the system using follow-up photometry and spectroscopy. A global fit to the system yields host-star properties of T_eff = 5900 ± 49 K, M_* = 0.945 ((+0.060)/(-0.054))M_⊙, R_* = 0.995 ± 0.015 R_⊙, L_* = 1.082 ((+0.051)/(-0.048)) L_⊙, log g_* = 4.418 ((+0.026)/(-0.025) (cgs), and [Fe/H] = -0.105 ± 0.077. KELT-23Ab is a hot Jupiter with a mass of M_p = 0.938 ((+0.045)/-0.042)) M …

Emergent Properties Of The Transport Of Sand, Eric Lenhart

Undergraduate Honors Theses

In the interest of drawing conclusions about Aeolian environments based on remote imaging, we investigated how air flow forms self-organizing patterns, such as ripples, across loose particulate surfaces. Specifically, we analyzed various models of sand transport, particularly Nishimori’s model, to note the effects of altering various parameters, including wind direction, saltation length, diffusion, and a saltation proportionality constant. As a measure of the frustration of the emergent patterns, Y-junctions were counted at various values of the parameters. A strong correlation with the saltation proportionality constant and no correlation with the saltation height were found. As an additional use of the …

Feasibility Of Circular Orbits For Proximity Operations In Strongly Perturbed Environments Around Uniformly Rotating Asteroids, Nicholas Peter Liapis

Doctoral Dissertations and Master's Theses

Asteroids have been mapped and observed since 1801 when an Italian astronomer Guiseppe Piazzi discovered Ceres (Serio, Manara, & Sicoli, 2002). Since then, asteroids have been growing in popularity throughout the scientific community because they are thought to hold the information we need to understand how the solar system developed and why life exists on earth, as well as potential precious resources. This research studies different types of orbits that have been performed to date around asteroids and how they can be reworked to require less control effort. Different types of missions that have been sent to asteroids are discussed, …

The Disk Structure Of Late Type Galaxies: Determining The Black Hole Mass Function Of Low Surface Brightness Galaxies Through Logarithmic Spiral Arm Pitch Angle Measurement, Michael S. Fusco

Graduate Theses and Dissertations

This dissertation pertains to the geometric structure of late type (spiral) galaxies, specifically on the relation between the logarithmic spiral pitch angle of the galactic spiral arms with other properties of the galaxy, such as central Supermassive Black Hole (SMBH) mass. Our work continues a study of the Black Hole Mass Function (BHMF) in local galaxies by recording the pitch angles of spiral galaxies with lower surface brightness than were previously included. We also conduct a case study on the structure of an interestingly shaped galaxy, UGC 4599. Previous studies on the topic of spiral arm pitch angles have measured …

One-Note-Samba Approach To Cosmology, Florentin Smarandache, Victor Christianto

Branch Mathematics and Statistics Faculty and Staff Publications

Inspired by One Note Samba, a standard jazz repertoire, we present an outline of Bose-Einstein Condensate Cosmology. Although this approach seems awkward and a bit off the wall at first glance, it is not impossible to connect altogether BEC, Scalar Field Cosmology and Feshbach Resonance with Ermakov-Pinney equation. We also briefly discuss possible link with our previous paper which describes Newtonian Universe with Vortex in terms of Ermakov equation.

Pipeline For Variable Star Detection And Eclipsing Binary Characterization, Moises Castillo

Theses and Dissertations

Stars have been observed and recorded since ancient times. Practices of documenting brightness led to observations of variability. Optical CCD observations of eclipsing binary stars were made with instruments at UTRGV Dr. Cristina Valeria Torres Memorial Astronomical Observatory. There are two main goals for this project. The first goal is to create a pipeline written in python (lightcurator) that creates a framework for detecting variable stars. The pipeline starts by creating a list of ccd frames written in FITS format of an eclipsing binary star observation. These object frames are expected to be already reduced, but lightcurator provides tools to …

Adsorption Driven Regolith-Atmospheric Water Vapor Transfer On Mars: An Analysis Of Phoenix Tecp Data, Holly Nicole Farris

Graduate Theses and Dissertations

NASA’s Phoenix mission allowed for investigations of Martian diurnal water vapor cycles through the collection of temperature, relative humidity, and electric conductivity data by the Thermal and Electric Conductivity Probe (TECP) instrument. Using this data and previous experimental data, we propose a regolith-driven adsorption-desorption regime at the Phoenix landing site, where parameters intrinsic to the regolith are controlling localized relative humidity at the surface. To constrain these parameters, we model adsorption as a function of temperature and relative humidity across various Mars-relevant materials, defined by two layer-based adsorption theories: Langmuir (monolayer) and Brunauer-Emmett-Teller or BET (multilayer). Langmuir serves as an …

Electron Energization By Parallel Electric Fields In Poloidal Standing Waves, P. A. Damiano, Eun-Hwa Kim, Jay R. Johnson, P. Porazik

Faculty Publications

A hybrid gyrofluid‐kinetic electron model is adapted and used to simulate poloidal standing modes for different electron temperatures and azimuthal mode numbers. As in previous studies of toroidal standing modes, mirror force effects lead to increased parallel potential drops, monoenergetic electron energization, and wave energy dissipation as the ambient electron temperature is increased. A similar trend is also observed when the electron temperature is held fixed and the azimuthal mode number increased—owing to the narrowing of the azimuthal flux tube width, which necessitates more electron energization to carry the increased parallel current density. In both cases, the increase in electron …

Hyper Wide Field Imaging Of The Local Group Dwarf Irregular Galaxy Ic 1613: An Extended Component Of Metal-Poor Stars, Ragadeepika Pucha, Jeffrey Carlin, Beth Willman, Jay Strader, David Sand, Keith Bechtol, Jean Brodie, Denija Crnojević, Duncan Forbes, Christopher Garling, Jonathan Hargis, Annika Peter, Aaron Romanowsky

Faculty Publications

Stellar halos offer fossil evidence for hierarchical structure formation. Since halo assembly is predicted to be scale-free, stellar halos around low-mass galaxies constrain properties such as star formation in the accreted subhalos and the formation of dwarf galaxies. However, few observational searches for stellar halos in dwarfs exist. Here we present gi photometry of resolved stars in isolated Local Group dwarf irregular galaxy IC 1613 (M sstarf ~ 108 M ⊙). These Subaru/Hyper Suprime-Cam observations are the widest and deepest of IC 1613 to date. We measure surface density profiles of young main-sequence, intermediate to old red giant branch, and …

Fabrication Of Core–Shell Cofe2o4@Hap Nanoparticles: A Novel Magnetic Platform For Biomedical Applications, D. Karthickraja, S. Karthi, G. A. Kumar, Gamage Chamath Dannangoda, Karen S. Martirosyan, E. L. Girija

Physics & Astronomy Faculty Publications

Core–shell CoFe2O4@HAp magnetic nanoparticles were successfully prepared by a simple two-step hydrothermal process, and their physicochemical and magnetic properties were studied. X-ray diffraction and Fourier transform infrared spectroscopy of the as-synthesized samples reveal that the nanoparticles are composed of both phases (HAp@CoFe2O4). The core–shell formation was confirmed by TEM and from the magnetization studies using a vibrating sample magnetometer (VSM), and the ferromagnetic nature of the synthesized core–shell nanoparticles at room temperature was confirmed by saturation magnetization (Ms) and coercivity values of 9.04 emu g−1 and 0.1 T, respectively. It has been observed that heat treatment enhanced the …

Spatially Resolved Stellar Kinematics Of The Ultra-Diffuse Galaxy Dragonfly 44. I. Observations, Kinematics, And Cold Dark Matter Halo Fits, Pieter Van Dokkum, Asher Wasserman, Shany Danieli, Roberto Abraham, Jean Brodie, Charlie Conroy, Duncan Forbes, Christopher Martin, Matt Matuszewski, Aaron Romanowsky, Alexa Villaume

Faculty Publications

We present spatially resolved stellar kinematics of the well-studied ultra-diffuse galaxy (UDG) Dragonfly 44, as determined from 25.3 hr of observations with the Keck Cosmic Web Imager. The luminosity-weighted dispersion within the half-light radius is ${\sigma }_{1/2}={33}_{-3}^{+3}$ km s−1, lower than what we had inferred before from a DEIMOS spectrum in the Hα region. There is no evidence for rotation, with ${V}_{\max }/\langle \sigma \rangle \lt 0.12$ (90% confidence) along the major axis, in possible conflict with models where UDGs are the high-spin tail of the normal dwarf galaxy distribution. The spatially averaged line profile is more peaked than a …

Quantum Algorithms With Applications To Simulating Physical Systems, Anirban Ch Narayan Chowdhury

Physics & Astronomy ETDs

The simulation of quantum physical systems is expected to be an important application for quantum computers. The work presented in this dissertation aims to improve the resource requirements of quantum computers for solving simulation problems, by providing both novel quantum algorithms and improved implementations of existing ones. I present three main results that cover diverse aspects of simulation including equilibrium physics, the preparation of useful quantum states, and simulations based on classical stochastic processes. The results rely on established quantum algorithms and other recent techniques which I review. My first original contribution is a new quantum algorithm to sample from …

Circumbinary Disk Inner Radius As A Diagnostic For Disk–Binary Misalignment, Alessia Franchini, Stephen H. Lubow, Rebecca G. Martin

Physics & Astronomy Faculty Research

We investigate the misalignment of the circumbinary disk around the binary HD 98800 BaBb with eccentricity e sime 0.8. Kennedy et al. observed the disk to be either at an inclination of 48° or polar aligned to the binary orbital plane. Their simulations showed that alignment from 48° to a polar configuration can take place on a shorter timescale than the age of this system. We perform hydrodynamical numerical simulations in order to estimate the cavity size carved by the eccentric binary for different disk inclinations as an independent check of polar alignment. Resonance theory suggests that torques on the …

Searching For Supermassive Binary Black Holes And Their Gravitational Waves, Karishma Bansal

Physics & Astronomy ETDs

The recent discovery of gravitational waves (GWs) by the LIGO collaboration has opened a new observing window on the universe, but it is limited to the GWs in the frequency range of 10-1000 Hz. The main motivation of this thesis is to consider the possibility of detecting low frequency (nHz) GWs. In the pursuit of these waves, we need to understand their source of origin and build a detector with the required sensitivity. Low-frequency waves are expected as a result of coalescing binary supermassive black holes (SMBBHs). We hope to detect these waves in the near future using pulsar timing …

Studying The Properties Of Sf6 Gas Mixtures For Directional Dark Matter Detection, Randy J. Lafler

Physics & Astronomy ETDs

Although dark matter comprises approximately 85\% of the matter content of the universe, direct detection of dark matter remains elusive. As the available parameter space for dark matter candidates is pushed to lower and lower limits, the demand for larger, more sensitive detectors continues to grow. Although upscaling the detector improves the sensitivity, it greatly increases the cost and complexity of the experiment. Even after a dark matter signal is detected, there remains the possibility that an unknown background mimics the dark matter signal. Consequently, verifying the dark matter origin of a detection signal is an issue for any dark …