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Stars, Interstellar Medium and the Galaxy Commons™

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2023

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Articles 31 - 41 of 41

Full-Text Articles in Stars, Interstellar Medium and the Galaxy

Physical Properties And Chemical Composition Of Comets, Olga Harrington Jan 2023

Physical Properties And Chemical Composition Of Comets, Olga Harrington

Electronic Theses and Dissertations, 2020-2023

Comets and Centaurs are icy remnants from the formation of the solar system. Analyzing the physical properties of their nuclei and their production rates can serve as powerful tools for tracing primitive solar system material. The four research projects in this dissertation examine these properties in comets and Centaurs. The first project focuses on observations of main belt comet 176P/LINEAR that were obtained with the Kepler space telescope. Optical lightcurves were used to constrain models of the nucleus's spin pole axis, shape and activity level. The second project used millimeter-wavelength spectra from the Arizona Radio Observatory Submillimeter Telescope and infrared …

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Impact On Infinite Asteroids: Analysis Of Ejecta Outcomes In Small Body Binary Systems, Jennifer Larson Jan 2023

Impact On Infinite Asteroids: Analysis Of Ejecta Outcomes In Small Body Binary Systems, Jennifer Larson

Electronic Theses and Dissertations, 2020-2023

Binary asteroid systems make up roughly 15% of objects occupying near-Earth space, the Main Belt, and trans-Neptunian space. The impact history of asteroids in binary systems represents an interesting aspect of the general problem pertaining to the nature and evolution of surfaces for such objects. Specifically, the post-impact dynamics of ejecta and its relation to surface modification is a challenging question owing, in part, to the unusual gravitational field in a binary system and the subsequent capture and emplacement of debris on either binary component. Observable differences or similarities between the two bodies in the color, reflectance, thermal properties, and …

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Development Of Regolith Simulants Of Lunar Permanently Shadowed Regions And Jupiter Trojan Asteroids, Karlis Slumba Jan 2023

Development Of Regolith Simulants Of Lunar Permanently Shadowed Regions And Jupiter Trojan Asteroids, Karlis Slumba

Electronic Theses and Dissertations, 2020-2023

Every scientific experiment or innovation goes through a phase of testing equipment. This is not only true for experiments in the laboratory, but also very relevant for experiments on other planetary bodies. In order to test tools and robotic equipment that are destined for another planet, moon, asteroid or comet, it is necessary to simulate the regolith environment on that surface. In this thesis we have provided an overview of two methods for regolith simulant development. In one approach we made simulants in different compositions to find the best spectral fit to Jupiter Trojan asteroids. At visible to near-infrared (VNIR) …

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Bifurcation Levels Of The Integral Manifolds Of The Newtonian N-Body Problem, Hannah G. Havel Jan 2023

Bifurcation Levels Of The Integral Manifolds Of The Newtonian N-Body Problem, Hannah G. Havel

CURE Proceedings

The N-body problem, first proposed by Isaac Newton, is a field of study in mathematics and physics that involves predicting the motion of particles moving under their mutual gravitational attraction. It has significance to many areas of science, including physics and computer science, and is crucial in understanding how the universe works. In fact, it was a primary motivation for Newton's development of calculus. An important application of the N-body problem is within celestial mechanics and involves how planets and other celestial bodies move with mutual gravitational attraction. It is important in developing how satellites behave in space using complicated …

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Clusters, Curves, And Centroids: Stellar Flare Morphology In The Ultraviolet, Vera Berger Jan 2023

Clusters, Curves, And Centroids: Stellar Flare Morphology In The Ultraviolet, Vera Berger

Pomona Senior Theses

With a novel sample of 495 high-cadence light curves for stellar flares in the near-ultraviolet, I explore similarity measures, clustering algorithms, averaging methods, and curve fitting techniques for time series. This work seeks to provide insight into whether stellar flares are similar across stars, if we can identify physically meaningful patterns in their light curves, and how to construct a comprehensive model for flares. I construct the first empirical template for flare light curves in the ultraviolet, and compute ``average elements" of flares displaying complex features such as quasi-periodic oscillations and multipeak structures. Developing accurate models for flares in the …

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S-Type Stars: Line List For The A²Π-X²Σ⁺ Band System Of Lao, P. F. Bernath, R. Dodangodage, J. Liévin Jan 2023

S-Type Stars: Line List For The A²Π-X²Σ⁺ Band System Of Lao, P. F. Bernath, R. Dodangodage, J. Liévin

Chemistry & Biochemistry Faculty Publications

LaO bands are found in the spectra of cool S-type stars. The bands of the A2Π–X2Σ+ transition with v' ⩽ 3 and v'' ≤ 4 are rotationally analyzed, providing spectroscopic constants for the A2Π state. Line strengths are calculated using an ab initio transition dipole moment function, and radiative lifetimes for the A2Π state have also been computed. A line list for the A2Π–X2Σ+ transition of LaO is provided and can be used to determine LaO stellar abundances.

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Astr 1: General Astronomy, David Goldberg Jan 2023

Astr 1: General Astronomy, David Goldberg

Open Educational Resources

No abstract provided.

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A Theoretical Study Of Elementary Processes In Interstellar Plasma, Joshua Forer Jan 2023

A Theoretical Study Of Elementary Processes In Interstellar Plasma, Joshua Forer

Graduate Thesis and Dissertation 2023-2024

Interstellar plasma — interstellar clouds in particular — play an important role in determining the structure and evolution of galaxies. Understanding the time evolution of such plasmas requires knowledge of the chemical processes that drive their dynamics. Two processes are studied in this dissertation: radiative electron attachment (REA) via dipole-bound states (DBSs) and dissociative recombination (DR). Of the several hundred molecules detected in the interstellar medium, only eight anions have been detected: CN-, C3N-, C5N-, C7N-, C4H-, C6H-, C8H-, and C10H-. Their production mechanism is not well known; REA was suggested as a possible formation pathway, but previous theoretical studies …

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The Radial Quenching Progression Of Nearby Galaxies, Chenyu Zhao Jan 2023

The Radial Quenching Progression Of Nearby Galaxies, Chenyu Zhao

Theses and Dissertations--Physics and Astronomy

In this dissertation, we explore the spatial distribution of quiescent regions within galaxies using data from the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory (SDSS-IV MaNGA). Our analysis focuses on a radial range spanning from 0.3 R e to 1.2 R e and involves the development of innovative data selection and processing methods. Through this investigation, we identify two prominent types of transition galaxies: central-star-forming galaxies (C-SF galaxies) and central-quiescent galaxies (C-Q galaxies). Notably, we observe a correlation between galaxy mass and the predominant type of transition, with more massive galaxies tending to be C-Q …

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A Multidimensional View On The Emission-Line Diagnostics Of The Warm Ionized Gas In Nearby Galaxies, Xihan Ji Jan 2023

A Multidimensional View On The Emission-Line Diagnostics Of The Warm Ionized Gas In Nearby Galaxies, Xihan Ji

Theses and Dissertations--Physics and Astronomy

The baryonic cycle, being a fundamental process that shapes the cosmic ecosystem, describes the transformation and migration of baryonic matter in different phases. The warm ionized interstellar medium (ISM), defined as low-density gas that has temperature of the order of 10,000 K, represents an important link of the baryonic cycle and can be produced by a variety of energetic activities in galaxies, such as star formations, active galactic nuclei, and so forth. More importantly, the formation and evolution of the warm ionized gas not only traces the ongoing activities of the galaxies, but also reveals the past evolution of galaxies …

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Towards A Prototype Paleo-Detector For Supernova Neutrino And Dark Matter Detection, Emilie Marie Lavoie-Ingram Jan 2023

Towards A Prototype Paleo-Detector For Supernova Neutrino And Dark Matter Detection, Emilie Marie Lavoie-Ingram

UNF Graduate Theses and Dissertations

Using ancient minerals as paleo-detectors is a proposed experimental technique expected to transform supernova neutrino and dark matter detection. In this technique, minerals are processed and closely analyzed for nanometer scale damage track remnants from nuclear recoils caused by supernova neutrinos and possibly dark matter. These damage tracks present the opportunity to directly detect and characterize the core-collapse supernova rate of the Milky Way Galaxy as well as the presence of dark matter. Current literature presents theoretical estimates for these potential tracks, however, there is little research investigating the experimental feasibility of this technique. At the University of North Florida, …

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