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The Loneliest Galaxies In The Universe: A Gama And Galaxyzoo Study On Void Galaxy Morphology, Lori E. Porter, Benne W. Holwerda 2021 University of Louisville

The Loneliest Galaxies In The Universe: A Gama And Galaxyzoo Study On Void Galaxy Morphology, Lori E. Porter, Benne W. Holwerda

The Cardinal Edge

The large-scale structure (LSS) of the universe is comprised of galaxy filaments, tendrils, and voids. The majority of the universe’s volume is taken up by these voids, which exist as underdense, but not empty, regions. The galaxies found inside voids are void galaxies and expected to be some of the most isolated objects in the universe. However, their standard morphology remains poorly studied. This study, using the Galaxy and Mass Assembly (GAMA) survey and Galaxy Zoo’s SDSS survey, aims to remedy this. To do so, survey results from GAMA have been plotted using the Sérsic index (n) to ...


Strong Inclination Pacing Of Climate In Late Triassic Low Latitudes Revealed By The Earth-Saturn Tilt Cycle, Miranda Margulis-Ohnuma, Jessica Whiteside, Paul Olsen 2021 Yale University

Strong Inclination Pacing Of Climate In Late Triassic Low Latitudes Revealed By The Earth-Saturn Tilt Cycle, Miranda Margulis-Ohnuma, Jessica Whiteside, Paul Olsen

The Yale Undergraduate Research Journal

Gravitational interactions among masses in the solar system are recorded in Earth’s paleoclimate history because variations in the geometry of Earth’s orbit and axial orientation modulate insolation. However, astronomical models are unreliable before ~50 Ma due to the chaotic nature of the solar system and therefore must be constrained using geological observations. Here, we use environmental proxies from paleo-tropical Late Triassic lake deposits of the Newark Rift Basin to identify and tune to previously undescribed strong variations in orbital inclination. Tuning to the 173 kyr Earth-Saturn inclination cycle, theoretically stable due to the high mass of Saturn, reveals ...


Directly Determined Properties Of Hd 97658 From Interferometric Observations, Tyler G. Ellis, Tabetha Boyajian, Kaspar von Braun, Roxanne Ligi, Denis Mourard, Diana Dragomir, Gail H. Schaefer, Christopher D. Farrington 2021 Louisiana State Univ, 202 Nicholson Hall, Baton Rouge, LA 70803 USA

Directly Determined Properties Of Hd 97658 From Interferometric Observations, Tyler G. Ellis, Tabetha Boyajian, Kaspar Von Braun, Roxanne Ligi, Denis Mourard, Diana Dragomir, Gail H. Schaefer, Christopher D. Farrington

Faculty Publications

We conducted interferometric observations with the CHARA Array of transiting super-Earth host HD 97658 and measured its limb-darkened angular diameter to be theta(LD) = 0.314 +/- 0.004 mas. The combination of the angular diameter with the Gaia EDR3 parallax value with zero-point correction (pi = 46.412 +/- 0.022 mas, d =21.546 +/- 0.011 pc) yields a physical radius of R-star = 0.728 +/- 0.008 R-circle dot. We also measured the bolometric flux of the star to be F-bol = 2.42 +/- 0.05 x 10(-8) erg s(-1) cm(-2), which, together with angular size, allows a measurement ...


A Unified Approach To M Dwarf Ages, Rocio Kiman 2021 The Graduate Center, City University of New York

A Unified Approach To M Dwarf Ages, Rocio Kiman

Dissertations, Theses, and Capstone Projects

Estimating ages of M dwarfs, the lowest mass stars in the Galaxy, is a current unresolved problem in Astrophysics. This dissertation focuses on developing a method to estimate ages for M dwarfs. This method consists of combining different age indicators in a Bayesian framework to achieve a precise age measurement. The age indicators I use are: 1) position in the color-magnitude diagram which is a proxy for effective temperature and luminosity, 2) movement of the stars in the Galaxy, or its 3D kinematics, 3) magnetic activity, measured by the Halpha emission line of the spectrum. In this dissertation I analyze ...


Approximate Solutions Of Nonlinear Partial Differential Equations Using B-Polynomial Bases, Muhammad I. Bhatti, Md. Habibur Rahman, N. Dimakis 2021 The University of Texas Rio Grande Valley

Approximate Solutions Of Nonlinear Partial Differential Equations Using B-Polynomial Bases, Muhammad I. Bhatti, Md. Habibur Rahman, N. Dimakis

Physics and Astronomy Faculty Publications and Presentations

A multivariable technique has been incorporated for guesstimating solutions of Nonlinear Partial Differential Equations (NPDE) using bases set of B-Polynomials (B-polys). To approximate the anticipated solution of the NPD equation, a linear product of variable coefficients ai(t) and Bi(x) B-polys has been employed. Additionally, the variable quantities in the anticipated solution are determined using the Galerkin method for minimizing errors. Before the minimization process is to take place, the NPDE is converted into an operational matrix equation which, when inverted, yields values of the undefined coefficients in the expected solution. The nonlinear terms of the NPDE are combined ...


Table Of Contents, 2021 University of South Carolina

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


2021 Scas Annual Meeting Program And Bulletin, 2021 University of South Carolina

2021 Scas Annual Meeting Program And Bulletin

Journal of the South Carolina Academy of Science

No abstract provided.


Developing A Bytownite Calibration Curve As A Lunar Analogue, Trevor W. Matterson 2021 Western University

Developing A Bytownite Calibration Curve As A Lunar Analogue, Trevor W. Matterson

Undergraduate Student Research Internships Conference

Planetary analogue materials are useful to help interpret and predict planetary processes on other planetary bodies that we cannot observe directly. Lunar analogue materials include terrestrial rocks and minerals with compositions and textures like those on the moon. This project investigates the lunar analogue mineral bytownite to quantify shock effects on the moon using strain related mosaicity determined through micro x-ray diffraction (µXRD). Calibrating strain information as a function of shock pressure for these minerals will enable us to extract peak shock pressures (in GPa) from naturally shocked materials, such as lunar meteorites and Apollo samples, using µXRD


Development And Distribution Of Thermometry Hardware For The Simons Observatory, Samuel Day-Weiss 2021 Yale University

Development And Distribution Of Thermometry Hardware For The Simons Observatory, Samuel Day-Weiss

The Yale Undergraduate Research Journal

The Simons Observatory (SO) is a new cosmic microwave background (CMB) experiment consisting of four telescopes. SO is being constructed at an elevation of 5,190 meters on Cerro Toco in the Atacama Desert in Chile, and is set to begin observation in 2022. SO will employ 60,000 detectors, yielding a sensitivity greater than all previous CMB experiments. To achieve low noise performance the telescope cryostats will be cooled to ~100 mK using low temperature dilution refrigerators. Measuring cryostat temperatures is essential for pre-deployment testing, telescope installation, and telescope monitoring during observation. The purpose of this project is to ...


Luminosity Functions Of Galaxy Clusters In The Aquarius And Microscopium Superclusters, Logan A. Hess 2021 The University of Maine

Luminosity Functions Of Galaxy Clusters In The Aquarius And Microscopium Superclusters, Logan A. Hess

Electronic Theses and Dissertations

We examine physical properties of several galaxy clusters located within the Aquarius (AQR) and Microscopium (MSC) super-cluster complexes via their luminosity functions, fitted using Schechter functions. Images of clusters were acquired via the DECam (Dark Energy Camera) imager of the 4-meter diameter telescope at CTIO (Cerro Tololo Inter-American Observatory). We observe six clusters in our sample; four from the Aquarius supercluster (AQR 2541, 2546, 2554, 2555) and two from the Microscopium supercluster (MSC 3695, 3696). Magnitude information and density of member galaxies in each cluster were extracted via the SExtractor software utility from obtained images. We correct for background by ...


On The Rectilinear Motion Of Three Bodies Mutually Attracting Each Other, Sylvio R. Bistafa 2021 University of Sao Paulo

On The Rectilinear Motion Of Three Bodies Mutually Attracting Each Other, Sylvio R. Bistafa

Euleriana

This is an annotated translation from Latin of E327 -- De motu rectilineo trium corporum se mutuo attrahentium (“On the rectilinear motion of three bodies mutually attracting each other”). In this publication, Euler considers three bodies lying on a straight line, which are attracted to each other by central forces inversely proportional to the square of their separation distance (inverse-square law). Here Euler finds that the parameter that controls the relative distances among the bodies is given by a quintic function.


Euler's Three-Body Problem, Sylvio R. Bistafa 2021 University of Sao Paulo

Euler's Three-Body Problem, Sylvio R. Bistafa

Euleriana

In physics and astronomy, Euler's three-body problem is to solve for the motion of a body that is acted upon by the gravitational field of two other bodies. This problem is named after Leonhard Euler (1707-1783), who discussed it in memoirs published in the 1760s. In these publications, Euler found that the parameter that controls the relative distances among three collinear bodies is given by a quintic equation. Later on, in 1772, Lagrange dealt with the same problem, and demonstrated that for any three masses with circular orbits, there are two special constant-pattern solutions, one where the three bodies ...


Space Science And Social Media: Automating Science Communication On Twitter, Maia Williams 2021 Bowling Green State University

Space Science And Social Media: Automating Science Communication On Twitter, Maia Williams

Honors Projects

This project analyzes how social media is used to engage general audiences in astronomy and space science, as well as ways to improve engagement through automation. Tweets from five space science organizations were sampled. The engagement rate for each tweet was calculated from the number of interactions it received. Accounts that tweet more per day had more followers, and accounts with more followers received more interactions. This project also investigated how to build a Twitter bot to automate science communication. Using NASA Application Programming Interfaces, a Twitter bot was written in Python to tweet images taken by the NASA Mars ...


Dirac-Born-Infeld Warm Inflation Realization In The Strong Dissipation Regime, Meysam Motaharfar, Rudnei O. Ramos 2021 Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA

Dirac-Born-Infeld Warm Inflation Realization In The Strong Dissipation Regime, Meysam Motaharfar, Rudnei O. Ramos

Faculty Publications

We consider warm inflation with a Dirac-Born-Infeld (DBI) kinetic term in which both the non-equilibrium dissipative particle production and the sound speed parameter slow the motion of the inflaton field. We find that a low sound speed parameter removes, or at least strongly suppresses, the growing function appearing in the scalar of curvature power spectrum of warm inflation, which appears due to the temperature dependence in the dissipation coefficient. As a consequence of that, a low sound speed helps to push warm inflation into the strong dissipation regime, which is an attractive regime from a model building and phenomenological perspective ...


Dark Matter Detection Materials, James E. Harrison IV 2021 University of North Florida

Dark Matter Detection Materials, James E. Harrison Iv

PANDION: The Osprey Journal of Research and Ideas

The purpose of this paper is to review the different methods and materials used in the detection of dark matter. Special attention is given to materials in the solid state, but other materials are briefly mentioned for the sake of completeness. After a review, we discuss the viability of each material as a detector, and determine what advantages each material has, and what method of detection works best for each material. We conclude by discussing the potential outcomes of a null detection.


Using Methanol Masers To Probe High Mass Star Forming Regions, Naomi S. Shechter, Anuj P. Sarma 2021 DePaul University, Chicago

Using Methanol Masers To Probe High Mass Star Forming Regions, Naomi S. Shechter, Anuj P. Sarma

DePaul Discoveries

Compared to low mass stars, the formation of high mass stars is not well understood. To understand better how high mass stars form, we can utilize masers, naturally amplified point sources of microwave radiation. One example is the methanol maser, which falls into two categories. Class I methanol masers form in the bipolar outflows from the protostar, and Class II masers form in the accretion disk. Their compact size and intensity make them an excellent source of information about the process of high mass star formation. We compiled a modest database of Class I and II methanol masers through a ...


An Investigation Of Water Masers In High Mass Star Forming Regions, Eleanor A. Webb 2021 DePaul University

An Investigation Of Water Masers In High Mass Star Forming Regions, Eleanor A. Webb

DePaul Discoveries

Within deep space are massive molecular clouds and within these molecular clouds, stars form. In these regions of star formation, masers can occur. I studied the presence of water masers within these high mass star forming regions. This was done in order to ascertain whether or not there is a correlation between the intensity of water masers versus the star formation activity within the molecular clouds. My findings provide answers to my specific research questions and includes information on the location of the water masers I observed with the star-forming regions. These findings provide information on water masers and sets ...


Wallaby Pre-Pilot Survey: H I Content Of The Eridanus Supergroup, B. Q. For, J. Wang, Tobias Westmeier, O. I. Wong, C. Murugeshan, L. Staveley-Smith, H. M. Courtois, D. Pomarede, Juan P. Madrid 2021 University of Western Australia

Wallaby Pre-Pilot Survey: H I Content Of The Eridanus Supergroup, B. Q. For, J. Wang, Tobias Westmeier, O. I. Wong, C. Murugeshan, L. Staveley-Smith, H. M. Courtois, D. Pomarede, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We present observations of the Eridanus supergroup obtained with the Australian Square Kilometre Array Pathfinder (ASKAP) as part of the pre-pilot survey for the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). The total number of detected H I sources is 55, of which 12 are background galaxies not associated with the Eridanus supergroup. Two massive H I clouds are identified and large H I debris fields are seen in the NGC 1359 interacting galaxy pair, and the face-on spiral galaxy NGC 1385. We describe the data products from the source finding algorithm and present the basic parameters. The ...


The Design, Creation, And Cognitive Evaluation Of Ranking Tasks In Introductory Astronomy, Emily A. Welch 2021 University of Nebraska - Lincoln

The Design, Creation, And Cognitive Evaluation Of Ranking Tasks In Introductory Astronomy, Emily A. Welch

Theses, Dissertations, and Student Research: Department of Physics and Astronomy

Ranking tasks are a type of interactive formative assessment. They allow students to explore a concept by ranking similar situations for a specified variable, preferably without computation of that variable. I created two sets of introductory astronomy ranking tasks: the first connects the Hertzsprung–Russell (HR) diagram and the Stephan-Boltzmann luminosity equation; the second uses the transit method (TM) to rank exoplanets by comparing the depth, duration, and frequency of transits.

These tasks are designed within the constructivist pedagogical framework. They require students to call upon their own relevant schema to establish an assessment rule by which to rank the ...


Extending Core-Collapse Supernova Simulations: From The Onset Of Explosion To Shock Breakout, Michael A. Sandoval 2021 University of Tennessee, Knoxville

Extending Core-Collapse Supernova Simulations: From The Onset Of Explosion To Shock Breakout, Michael A. Sandoval

Doctoral Dissertations

A core-collapse supernova (CCSN) is the result of a massive star’s core collapsing due to the inability of electron degeneracy pressure to provide sufficient support against gravity. Currently, there is a disconnect between when most three-dimensional CCSN simulations end (seconds) and when the explosion would reach the surface of the star and become visible (hours to days). We present three-dimensional simulations of CCSNe using the FLASH code that follow the progression of the explosion to the stellar surface, starting from neutrino-radiation hydrodynamic simulations of the first seconds performed with the Chimera code. We consider a 9.6-M zero-metallicity progenitor ...


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