Astrophysics and Astronomy Commons^™

The Leoncino Dwarf: A Neutral Hydrogen Analysis Of Agc 198691 And Its Extremely Metal-Poor Environment, Tylyn Page

Macalester Journal of Physics and Astronomy

Studies of low-mass galaxies are important for populating the low-mass ends of funda- mental physical relations. Extremely metal-poor (XMP) galaxies are low-mass galaxies with gas-phase oxygen abundances of 12+log(O/H) ≤ 7.35 ( 1/20 Z⊙), and are especially interesting as proxies for studying the distant past, as their chemical makeup resembles those of galaxies in the early universe. AGC 198691, referred to as the Leoncino Dwarf, was discovered through the Arecibo Legacy Fast ALFA (ALFALFA) survey and found to have an oxygen abundance of less than 3% Z⊙. Presented here are the results of recent Karl G. Jansky Very Large Array …

Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore

Macalester Journal of Physics and Astronomy

The current energy grid in the United States is dominated by carbon intense energy generation methods that are based on production when and where it is required. However, solar and wind power have proved themselves as the most promising carbon free energy generation sources. Due to the unpredictable and uncontrollable nature of energy production from solar and wind, large scale integration of these resources into the electric grid will require robust storage capacity. In this project, we model the energy grid of the Midcontinent Independent System Operator (MISO) energy region with high concentrations of solar and wind power to analyze …

Probing The Magnetic Fields In Cosmic Web Filaments, Andrew L. Mizener

Macalester Journal of Physics and Astronomy

We present a project to constrain the properties of magnetic fields in Cosmic Web filaments. We first perform rotation measure (RM) synthesis on 24 S-band Karl G Jansky Very Large Array (VLA) observations of moderate-redshift active galactic nuclei (AGN). These observations are combined with an existing catalog of Cosmic Web filaments in order to determine the number of filaments a given sight-line passes near or through. By tracking how observables such as rotation measure and polarization fraction change as a function of the number of intervening cosmic web filaments, we take the first steps towards providing observational constraints on the …

Shape Model Of Potentially Hazardous Asteroid 1981 Midas From Radar And Lightcurve Observations, Riley Mcglasson

Macalester Journal of Physics and Astronomy

We report observations of potentially hazardous, Apollo-class asteroid 1981 Midas, which passed 0.090 au from Earth (35 lunar distances) on March 21, 2018. During this close approach, Midas was observed by radar both from the Arecibo Observatory on March 21 through 25 (five nights), and from NASA's Goldstone Deep Space Communications Complex on March 19 and 21. These radar observations yielded one-dimensional continuous-wave spectra and two-dimensional delay-Doppler images. In addition, there have been optical lightcurve observations of Midas during four apparitions (1987, 1992, 2004, and 2018), which showed a rotation period of 5.22 hours. Midas has an absolute magnitude of …

A Search For Pulsars Towards The Galactic Center, Jacob W. Hetrick, Kunal Mooley, Preshanth Jagannathan

Macalester Journal of Physics and Astronomy

We present observations from two separate methods for observing the Galactic Center in an attempt to characterize its pulsar and neutron star populations. A persistent puzzle of the past 20 years has been the lack of pulsar detections towards the Galactic Center, specifically within a few parsecs of the central supermassive black hole Sgr A*. This object is bright in the total intensity of its polarized emission, but is very weakly linearly polarized. We take advantage of these circumstances in an experimental search technique where we utilize the Faraday effect in an attempt to detect high rotation measure (RM) point …

Modeling Scavenging For A Hydraulic Free-Piston Engine, Nathan Davies

Macalester Journal of Physics and Astronomy

The hydraulic free-piston engine at the University of Minnesota offers a solution to improve the hydraulic efficiency and reduce emission output of off-road vehicles. We developed a MATLAB Simulink model to track the pressure, temperature, and mass profile of the fuel within the cylinder during operation. By varying different initial conditions of our model, we found that a higher intake manifold pressure and larger bottom dead center location results in higher scavenging efficiency. These results can be used to improve the controller of this engine and better maintain stable operation.

Band Extension And Possible Ridge Compression On Europa, Sarah Chinski

Macalester Journal of Physics and Astronomy

Jupiter's icy moon Europa has captivated and perplexed the scientific community since the discovery of its global liquid water ocean. Over the course of several missions to the Jovian system, high-resolution observations of Europa have determined that there are spreading zones where new crust is created, similar to the mid-ocean spreading tectonic process we observe on Earth. These features, known as bands, have symmetric hills and valleys, indicating brief events of activity where material from the interior is exuded through a central crack, and solidifies on both sides, creating two positive topography. Recently, Europan scientists have been questioning how these …

Electrical Measurement Of Sram Cell Variation And Sensitivity To Singe-Event Upsets By Low-Energy Protons, James M. Cannon

Macalester Journal of Physics and Astronomy

With the rise of the transistor in the 1970s, electronics shifted from analog circuitry, where values are stored on a continuum, to digital, in which ones and zeros are the law of the land. Transistors, as a class circuit element, can be affected by radiation and cosmic rays which then cause temporary or permanent failures, depending on the specifics of the situation. On Earth, this poses little risk with all electronics shielded by the magnetosphere, however for space bound electronics, the risks from these extraterrestrial particles are not so negligible. The first step in designing a mission to be able …

Design And Modal Analysis Of An Ultra-Wideband Receiver For Green Bank Observatory, Alyssa Bulatek

Macalester Journal of Physics and Astronomy

The next generation of radio receivers for astronomy will be marked by tenfold improvements in sensitivity. These sensitive receivers will be useful for the detection of broadband fast radio bursts and other transients as well as the efficient discovery of radio recombination lines among many other scientific pursuits. One contribution to these improvements is an increase to decade receiver bandwidths. The Green Bank Observatory (GBO) is currently in the process of fabricating a new ultra-wideband (UWB; 0.7 to 4.2 GHz) receiver for the Green Bank Telescope (GBT). The UWB receiver will be used by the North American Nanohertz Observatory for …

Alfalfa Harvest: Hi Imaging And 3d Modeling Of Candidate Local Group Dwarf Galaxies, Lilly Bralts-Kelly, Susie Paine, Elizabeth A. K. Adams, John M. Cannon

Macalester Journal of Physics and Astronomy

Isolated neutral hydrogen (HI) clouds, or "ultra-compact high-velocity clouds" (UCHVCs), form a small subset of detections by the Arecibo Legacy Fast ALFA (ALFALFA) blind extragalactic survey. These systems, if located within ~1 Mpc, would populate the lowest-mass end of the HI mass function. Subsequent optical imaging has revealed that some of these UCHVCs harbor associated (thought sparse) stellar populations, suggesting that they may be some of the most extreme galaxies known in the Local Volume, with properties akin to ultra-faint dwarf galaxies but with significant neutral gas reservoirs. In this work, we investigate the neutral hydrogen properties of six UCHVC …

Leoncino And Ugc 5186, Josh Bartz

Macalester Journal of Physics and Astronomy

AGC 198691 is commonly known as the Leoncino Dwarf and is one of the most metal poor galax- ies known. An Arecibo observation in 2011 first suggested that Leoncino could be gravitationally interacting with its neighbor UGC 5186. In this paper new VLA data is used to examine the H I com- ponent of both galaxies to determine their gravitational relationship. Although the VLA could not confirm intragalactic gas seen by Aricebo, the H I density and velocity components are strong indirect evidence of gravitational interaction. UGC 5186 has a large gaseous arm reaching in the direction of Leoncino. Additionally …

Congressional Committee Resources On Space Policy During The 115th Congress (2017-2018): Providing Context And Insight Into Us Government Space Policy, Bert Chapman

Libraries Faculty and Staff Presentations

Article 1 of the US Constitution assigns the US Congress numerous responsibilities. These include creating new laws, revising existing laws, funding government programs, and conducting oversight of these programs' performance. Oversight of US Government agency space policy programs is executed by various congressional space policy committees including the House and Senate Science Committees, Armed Services, and Appropriations Committees. These committees conduct many public hearings on space policy, which invite expert witnesses to testify on US space policy programs and feature debate on the strengths and weaknesses of these programs. Documentation produced by these committees is widely available to the public, …

Is Grb 110715a The Progenitor Of Frb 171209?, Xiang-Gao Wang, Long Li, Yuan-Pei Yang, Jia-Wei Luo, Bing Zhang, Da-Bin Lin, En-Wei Liang, Song-Mei Qin

Physics & Astronomy Faculty Research

The physical origin of fast radio bursts (FRBs) is unknown. Young magnetars born from gamma-ray bursts (GRBs) have been suggested as a possible central engine of FRBs. We test such a hypothesis by systematically searching for GRB–FRB spatial associations from 110 FRBs and 1440 GRBs. We find that one FRB event discovered by the Parkes telescope, FRB 171209, is spatially coincident with a historical long-duration GRB 110715A at z = 0.82. The afterglow of GRB 110715A is consistent with being powered by a millisecond magnetar. The extragalactic dispersion measure of FRB 171209 is in excess of that contributed by the …

Absolute Dimensions Of The Unevolved F-Type Eclipsing Binary Bt Vulpeculae, Guillermo Torres, Claud H. Sandberg Lacy, Francis C. Fekel, Matthew W. Muterspaugh

Information Systems and Engineering Management Research Publications

We report extensive differential V-band photometry and high-resolution spectroscopy for the 1.14 day, detached, double-lined eclipsing binary BT Vul (F0+F7). Our radial-velocity monitoring and light-curve analysis lead to absolute masses and radii of ${M}_{1}=1.5439\pm 0.0098\,{{ \mathcal M }}_{\odot }^{{\rm{N}}}$ and ${R}_{1}=1.536\pm 0.018\,{{ \mathcal R }}_{\odot }^{{\rm{N}}}$ for the primary, and ${M}_{2}=1.2196\pm 0.0080\,{{ \mathcal M }}_{\odot }^{{\rm{N}}}$ and ${R}_{2}=1.151\pm 0.029\,{{ \mathcal R }}_{\odot }^{{\rm{N}}}$ for the secondary. The effective temperatures are 7270 ± 150 K and 6260 ± 180 K, respectively. Both stars are rapid rotators, and the orbit is circular. A comparison with stellar evolution models from the MESA Isochrones …

Water On Mars—A Literature Review, Mohammad Nazari-Sharabian, Mohammad Aghababei, Moses Karakouzian, Mehrdad Karami

Civil and Environmental Engineering and Construction Faculty Research

To assess Mars’ potential for both harboring life and providing useable resources for future human exploration, it is of paramount importance to comprehend the water situation on the planet. Therefore, studies have been conducted to determine any evidence of past or present water existence on Mars. While the presence of abundant water on Mars very early in its history is widely accepted, on its modern form, only a fraction of this water can be found, as either ice or locked into the structure of Mars’ plentiful water-rich materials. Water on the planet is evaluated through various evidence such as rocks …

Finding Strong Gravitational Lenses In The Desi Decam Legacy Survey, Xiaosheng Huang, Christopher Storfer, V. Ravi, A. Pilon, M. Domingo, D. J. Schlegel, S. Bailey, A. Dey, R. R. Gupta, D. Herrera, S. Juneau, M. Landriau, D. Lang, A. Meisner, J. Moustakas, A. D. Myers, E. F. Schlafly, F. Valdes, B. A. Weaver, J. Yang, C. Yèche

Physics and Astronomy

We perform a semi-automated search for strong gravitational lensing systems in the 9000 deg2 Dark Energy Camera Legacy Survey (DECaLS), part of the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys. The combination of the depth and breadth of these surveys are unparalleled at this time, making them particularly suitable for discovering new strong gravitational lensing systems. We adopt the deep residual neural network architecture developed by Lanusse et al. for the purpose of finding strong lenses in photometric surveys. We compile a training sample that consists of known lensing systems in the Legacy Surveys and the Dark Energy Survey as …

Mineral-Surface Chemistry Of Hydroxyapatite And Urea-Rich Solutions, Estefania Garcia

Master of Science in Chemical Sciences Theses

On this planet the development of life requires six essential elements: C, H, O, N, P, and S. These elements are present in gaseous form, with the exception of phosphorus, which is primarily found in solid mineral sources. Phosphorus in biological systems is significant through its involvement in metabolic functions (e.g., Coenzyme A), cell structure (i.e., phospholipid membranes), and genetic storage/transfer (i.e., phosphodiester bonds in DNA and RNA). However, an ambiguity remains with the assimilation of phosphorus in biological systems, caused by its habitual presence in insoluble phosphate mineral sources. Recent research has found that insoluble phosphate …

Dust Condensation In Evolving Discs And The Composition Of Planetary Building Blocks, Min Li, Shichun Huang, Michail I. Petaev, Zhaohuan Zhu, Jason H. Steffen

Physics & Astronomy Faculty Research

Partial condensation of dust from the Solar nebula is likely responsible for the diverse chemical compositions of chondrites and rocky planets/planetesimals in the inner Solar system. We present a forward physical–chemical model of a protoplanetary disc to predict the chemical compositions of planetary building blocks that may form from such a disc. Our model includes the physical evolution of the disc and the condensation, partial advection, and decoupling of the dust within it. The chemical composition of the condensate changes with time and radius. We compare the results of two dust condensation models: one where an element condenses when the …

Discovering New Strong Gravitational Lenses In The Desi Legacy Imaging Surveys, Xiaosheng Huang, Christopher Storfer, A. Gu, V. Ravi, A. Pilon, W. Sheu, R. Venguswamy, S. Bankda, A. Dey, M. Landriau, D. Lang, A. Meisner, J. Moustakas, A. D. Myers, R. Sajith, E. F. Schlafly, D. J. Schlegel

Physics and Astronomy

We have conducted a search for new strong gravitational lensing systems in the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys’ Data Release 8. We use deep residual neural networks, building on previous work presented in Huang et al. (2020). These surveys together cover approximately one third of the sky visible from the northern hemisphere, reaching a z-band AB magnitude of ∼ 22.5. We compile a training sample that consists of known lensing systems as well as non-lenses in the Legacy Surveys and the Dark Energy Survey. After applying our trained neural networks to the survey data, we visually inspect and …

Determining The Rotational And Orbital Velocities Of Objects In The Solar System, Mark Jones

Undergraduate Honors Theses

Astronomers have been observing the night sky for many centuries to establish a better understanding for our universe and solar system. As part of their observations, astronomers characterize celestial bodies by fundamental properties such as mass, motion, and composition in order to provide further insight about the objects in question. As technology and science have evolved, the methods for measuring these properties have become more precise and accurate. One such methodology is known as spectroscopy, and it is a significant tool for observational astronomy. In this paper, we shall describe how we used astronomical spectroscopy to determine orbital and rotational …

Formation Pathways In Brightest Cluster Galaxies: Measuring The Distribution Of Ages, Metallicities, And Hydrodynamics Of Stellar Populations, Priscilla E. Holguin West

Physics

Brightest Cluster Galaxies (BCGs) are the most massive galaxies in the local universe and have had the full age of the universe to build. This makes their formation and evolution history particularly interesting as they offer a glimpse at potential evolutionary pathways for younger systems. We present the radial profile of ages, metallicities, and preliminary classification of companions to 23 BCGs observed using the SparsePak instrument on WIYN by running the STARLIGHT stellar population synthesis models. This analysis of the BCGs’ stellar populations is done by separating each BCG into different regions, and preliminary results of the stellar populations for …

Applying The Optimal Estimation Method For Retrieving Rayleigh-Scatter Lidar Temperatures In The Mesosphere, Jonathan Price, Robert Sica, Ali Jalali

Utah Space Grant Consortium

The Rayleigh-scatter lidar (RSL) system at the Atmospheric Lidar Observatory at Utah State University (ALO-USU) provided a rich database of absolute temperatures throughout the mesosphere from 45 km to above 90 km between 1993 and 2004. Recently, a new method for retrieving absolute temperatures from RSL observations has been developed by a group at the University of Western Ontario (UWO), Canada. The Optimal Estimation Method (OEM) uses machine learning to minimize a cost function by optimizing the temperature parameter in a forward model, in our case the lidar equation, to RSL data. This optimization provides some benefits over the existing …

Extreme Ultraviolet Application Of Carbon Nanotube Structures, Scott Olsen, Richard Vanfleet, David Allred, Steve Turley

Utah Space Grant Consortium

Windows for extreme ultraviolet (EUV) sources are challenging because of the lack of transparent materials in these wavelengths. Thus, differential pumping apertures and slits are standard. Our group has developed a carbon nanotube (CNT) window consisting of a dense array of square holes. The open area allows a large range of wavelengths to be transmitted, and the high density of holes restricts gas flow, allowing a large pressure difference with differential pumping. The versatility of CNTs allows us to select the peak transmission and pressure ratio (low/high). We have observed pressure ratios of 0.000924, 0.000667, 0.000494, and 0.00118 for air …

Great Salt Lake Halophilic Archaea As A Model For Possible Extant Life On Mars, Alex J. Breda, Michael J. Regan Jr.

Utah Space Grant Consortium

Expansive evaporite mineral deposits and other geological features on Mars are evidence of ancient lacustrine systems before the planet experienced global climatic change (~3.5 Ga). On Mars, as the surface water dried up, hypersaline lakes would have filled the ancient lake basins. On Earth, the Bonneville Basin, in the western United States, tells a similar story in a more recent timeframe. Today, the bottom of this basin is the modern Great Salt Lake (GSL) and the Bonneville Salt Flats. Evaporation of this freshwater lake left large evaporitic mineral deposits that continually supply salt to modern GSL. Parts of the lake …

Towards Gross-Pitaevskiian Description Of Solar System & Galaxies, Florentin Smarandache, Victor Christianto, Yunita Umniyati

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper, we argue that Gross-Pitaevskii model can be a more complete description of both solar system and spiral galaxies, especially taking into account the nature of chirality and vortices in galaxies. We also hope to bring out some correspondence among existing models, e.g., the topological vortex approach, Burgers equation in the light of KAM theory, and the Cantorian Navier-Stokes approach. We hope further investigation can be done around this line of approach.

Neusch Automated Filter System: A Custom-Designed Photo-Filter Switching Apparatus For Embry-Riddle’S 1 Meter Telescope, Tyler Neusch

Doctoral Dissertations and Master's Theses

The one-meter telescope on the roof of Embry-Riddle’s College of Arts and Sciences building in Daytona Beach, FL is an advanced piece of technology supporting education and public outreach. One part of this telescopic system is a custom-made Cassegrain Instrument Mount. This one-of-a-kind mount allows for multiple scientific instruments to be simultaneously mounted to the telescope. However, its mechanical layout prevents the use of a traditional device known as a filter wheel.

Filter wheels store multiple photo-filters each capable of filtering out all but certain wavelengths of light for use with a CCD camera. Therefore, a filter wheel allows the …

Searching For Optical Counterparts To Gravitational Waves, Richard Camuccio

Theses and Dissertations

The era of multi-messenger astronomy has begun. The coordinated activities of multiple, distinct observatories play a critical role in both responding to astrophysical transients and building a more comprehensive interpretation otherwise inaccessible to individual observations. The Transient Robotic Observatory of the South (TOROS) Collaboration has a global network of instruments capable of responding to several transient targets of opportunity. The purpose of this thesis is to demonstrate how optical observatories with small fields of view (degree) can follow up and observe astrophysical transients. TOROS facilities responded to three unique gravitational wave events during the second and third observational campaigns of …

Characterizing Plasma With Emission Tomography-Feasibility Study On Synthetic And Experimental Data, M. Nikolić, A. Samolov, A. Godunov, L. Vušković,, S. Popović

Physics Faculty Publications

We present a feasibility study on different tomographic algorithms to overcome the issues of finite sets of projection data, limited viewing angles, and noisy data, which cause the tomographic reconstruction to be an ill-posed inversion problem. We investigated three approaches: single angle Abel inversion, two angle approach, and multiple angle 2D plasma tomography. These methods were tested on symmetric and asymmetric sample functions and on experimental results from a supersonic flowing argon microwave plasma sustained in a cylindrical quartz cavity. The analysis focused on the afterglow region of the microwave flow where a plasmoid-like formation was observed. We investigated the …

Understanding Ice Mixtures Under Pluto Simulated Conditions And Their Implications For Geophysical Processes, Caitlin Joannah Ahrens

Graduate Theses and Dissertations

New Horizons at Pluto has given the planetary science community the first images of Pluto’s surface, including geologic wonders and compositional variability. Methane, nitrogen, and carbon monoxide make up the bulk of the volatile plutonian surface along with water ice. In this work, these three main volatiles are specifically investigated in the laboratory setting to understand the spectral properties and behavior of binary and ternary mixtures. The spectra are taken in the near-infrared wavelengths (1 – 2.5 µm) using Fourier transform infrared (FTIR) spectroscopy techniques utilizing the Pluto Simulation Chamber housed at the University of Arkansas, which can reach conditions …

Constraining Neutron Star Nuclear Equations Of State Based On Observational Data, Alexander Clevinger

Undergraduate Honors Thesis Projects

This project analyzes recent observational data of neutron stars. It uses this to data to constrain nuclear equations of state proposed by Oter. et al. based on the maximum masses proposed by these equations of state. I do this by using numerical integration of the Tolman-Oppenheimer-Volkov equation to provide equilibrium states for each proposed EoS.