Astrophysics and Astronomy Commons^™

A Review On Antibacterial Activity Of Nanoparticles, Badr-Edine Sadoq, Mohammed Reda Britel, Adel Bouajaj, Ramzi Maâlej, Ahmed Touhami, Marwa Abid, Hanen Douiri, Fakhita Touhami, Amal Maurady

Physics and Astronomy Faculty Publications and Presentations

The increasing resistance of bacteria to antibiotic agents is a main global public health problem. The use of nanoparticles is one of the promising ways to overcome microbial resistance to antimicrobial agents. Metal nanoparticles are increasingly used to target bacterial strains. Advances in nanotechnology, in particular the ability to synthesize nanoparticles of specific size and shape, are likely to lead to the development of new antibacterial agents. The antibacterial activities of nanoparticles are largely influenced by their sizes and large surface area/mass ratio. The antibacterial mechanisms of nanoparticles are poorly understood, but the currently accepted mechanisms include oxidative stress induction, …

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology., Lori E. Porter

College of Arts & Sciences Senior Honors Theses

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) data and Galaxy Zoo survey, aims to remedy this. For completeness purposes, we use void galaxies identified by Alpaslan et al. (2014) with stellar masses (M*) of 10 …

Analysis On High Mass X-Ray Binary Spectral Shape Dependence On Luminosity For Ngc3310, Izabela Pavel

Physics Undergraduate Honors Theses

In most normal galaxies, the most X-ray luminous sources are high-mass X-ray binaries (HMXBs), which are binary star systems that contain compact objects (black holes or neutron stars) accreting from massive (> 8M⊙) companion stars. These HMXBs are thought to have been important sources of ionizing emission within star-forming galaxies that may have contributed to the heating of the intergalatic medium (gas over large cosmic scales) in the early Universe. When studying how HMXBs contribute to interstellar medium feedback, a single spectral shape of an absorbed power-law is typically assumed to be universal. The goal of this thesis is to …

Methods For Preparing And Characterizing Granular Materials For Electron Yield Measurements, Tom Keaton

All Graduate Plan B and other Reports

This work presents a systematic study on sample preparation methods and accuracy of electron yield (EY) measurements of highly insulating, granular materials. EY measurements of highly insulating materials, especially those with high EY, are challenging due to the effects of sample charging even for very low fluence electron probe beams. EY measurements of particulates are complicated by: (i) roughness effects from particulate size, shape, coverage, and compactness; (ii) particle adhesion; (iii) substrate contributions; and (iv) electrostatic repulsion and potential barriers from charged particles and substrates. Numerous methods were explored to rigidly affix particles on conducting substrates at varying coverages for …

The Coeval Mass Assembly Of The Universe Via Supermassive Black Hole Accretion And Star Formation In Galaxies, Alyssa Sokol

Doctoral Dissertations

The possible co-evolution between galaxies and their central supermassive black holes is supported by the similarity in shape between the Star Formation Rate Density (SFRD) and Black Hole Accretion Rate Density (BHARD) out to z$\sim$ 3. This apparent connection between BH growth and star formation is only established globally; while both trends peak at z$\sim$ 2, the amount of stellar and black hole mass assembly occurring within the same galaxies is unknown. Computing these trends for the same galaxies will mitigate the present sample mismatch and can be accomplished with an IR-selected sample; however, the approach relies on a robust …

Euler And Venus' Suspicious Moon, Michael P. Saclolo

Euleriana

This is a brief note on Leonhard Euler's published German translation from the French of two memoirs read by Armand Henri Baudouin de Guémadeuc to the Paris Academy of Sciences in 1761 and published the same year. The memoirs report on observations made of the planet Venus, performed in Limoges, France by Jacques Montaigne, where he claimed to have detected a moon orbiting the Morning and Evening Star.

Stellar Binaries And Post-Merger Evolution: A Framework For Stellar Evolution And Nucleosynthesis In R Coronae Borealis Stars, Bradley Munson

LSU Doctoral Dissertations

We have developed a framework for simulating binary stars through all three relevant
timescales: the dynamical merger, thermal, and nuclear evolution. The framework begins by simulating a dynamical merger in a 3-dimensional hydrodynamics adaptive mesh refinement code, Octo-Tiger, and performing a spherical averaging calculation to map the post-merger remnant into the 1-dimensional stellar evolution code, MESA. In this work, we primarily utilize this framework for simulating double white dwarf mergers, which are believed to be the progenitor to R Coronae Borealis (RCB) stars. We evolve the post-merger in MESA and compare the computed surface abundances to those observed …

Optimizing Course Offerings In A Science Department, Yu Kay Law

Academic Chairpersons Conference Proceedings

We will discuss how enrollment data and faculty/advisor input can be used to maximize schedule efficiency in course offerings and providing for student success. We will also discuss how best to monitor and rearrange course schedules in light of actual enrollment.

Stellar Atmosphere Models For Select Veritas Stellar Intensity Interferometry Targets, Jackson Ladd Sackrider, Jason P. Aufdenberg, Katelyn Sonnen

Beyond: Undergraduate Research Journal

Since 2020 the Very Energetic Radiation Imaging Telescope Array System (VERITAS) has observed 48 stellar targets using the technique of Stellar Intensity Interferometry (SII). Angular diameter measurements by VERITAS SII (VSII) in a waveband near 400 nm complement existing angular diameter measurements in the near-infrared. VSII observations will test fundamental predictions of stellar atmosphere models and should be more sensitive to limb darkening and gravity darkening effects than measurements in the near-IR, however, the magnitude of this difference has not been systematically explored in the literature. In order to investigate the synthetic interferometric (as well as spectroscopic) appearance of stars …

Calculating MBh Scaling Relations For Agns Using 2d Galaxy Decomposition Software To Analyse Hst Images, Jewel A. Capili

Physics

This study uses the 2D galaxy decomposition software GALFIT developed by Dr. Chien Peng to analyse Hubble Space Telescope images of 14 Active Galactic Nuclei (AGNs) and obtain their M_BH-spheroid luminosity scaling relations for comparison with previous studies.

Speed Of Sound For Hadronic And Quark Phases In A Magnetic Field, Efrain J. Ferrer, A. Hackebill

Physics and Astronomy Faculty Publications and Presentations

In this paper we calculate the speed of sound for three phases that may exist inside a magnetized hybrid neutron star at different density regions: A hadronic phase at low densities, quark-matter in the magnetic dual chiral density wave (MDCDW) phase at intermediate densities and a free-quark phase modeled by the MIT bag model at higher densities. It is found that the speed of sound exhibits a non-monotonic behavior, that goes from values smaller than the conformal limit ( c 2 s < 1 / 3 ) in the hadronic phase, to peak ( c 2 s > 1 / 3 ) in the MDCDW phase, to finally reach the conformal limit ( c 2 s …

Evolution Of Coronal Magnetic Field Parameters During X5.4 Solar Flare, Seth H. Garland, Benjamin F. Akers, Vasyl B. Yurchyshyn, Robert D. Loper, Daniel J. Emmons

Faculty Publications

The coronal magnetic field over NOAA Active Region 11,429 during a X5.4 solar flare on 7 March 2012 is modeled using optimization based Non-Linear Force-Free Field extrapolation. Specifically, 3D magnetic fields were modeled for 11 timesteps using the 12-min cadence Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager photospheric vector magnetic field data, spanning a time period of 1 hour before through 1 hour after the start of the flare. Using the modeled coronal magnetic field data, seven different magnetic field parameters were calculated for 3 separate regions: areas with surface |Bz|≥ 300 G, areas of flare brightening seen in …

Periodicities And Plasma Density Structure Of Jupiter’S Dawnside Magnetosphere, Xuanye Ma, A.A. Schok, P.A. Delamere, B. Mino, P.A. Damiano, B. Zhang, A. Sciola

Publications

The ability to quantify variations in magnetic field topology and density within Jupiter’s magnetosphere is an important step in understanding the overall structure and dynamics. The Juno spacecraft has provided a rich data set in the dawnside magnetosphere. The recent Grid Agnostic MHD for Extended Research Applications (GAMERA) global simulation study by Zhang et al. (2021) showed a highly structured plasmadisc with closed magnetic field lines mapping between the outer dawn-tail flank and the high latitude polar region. To test these model predictions, we examined Juno’s magnetic field data and electron/energetic particle data to categorize portions of orbits 1-15 into …

Looking For Life, Conor C. Grubb

CAFE Symposium 2023

The topic of aliens is not just about conspiracy theories and tinfoil hats, through the years numerous respected scientists have weighed in and put thought into the topic. The Search for Extraterrestrial Intelligence (SETI) is closely tied to the Fermi Paradox and the Drake Equation. The Fermi Paradox considers why humans haven't already interacted with aliens if they exist, and the Drake Equation outlines potential variables that would influence the chances of humanity receiving radio contact from an alien civilization.

Wallaby Pilot Survey: H I Gas Kinematics Of Galaxy Pairs In Cluster Environment, Shin-Jeong Kim, Se-Heon Oh, Jing Wang, Lister Staveley-Smith, Bärbel S. Koribalski, Minsu Kim, Hye-Jin Park, Shinna Kim, Kristine Spekkens, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We examine the H I gas kinematics of galaxy pairs in two clusters and a group using Australian Square Kilometre Array Pathfinder (ASKAP) WALLABY pilot survey observations. We compare the H I properties of galaxy pair candidates in the Hydra I and Norma clusters, and the NGC 4636 group, with those of non-paired control galaxies selected in the same fields. We perform H I profile decomposition of the sample galaxies using a tool, BAYGAUD, which allows us to deblend a line-of-sight velocity profile with an optimal number of Gaussian components. We construct H I superprofiles of the sample galaxies via …

Naming Venus: An Exploration Of Goddesses, Heroines, And Famous Women, Kavya Beheraj

Dissertations, Theses, and Capstone Projects

Humans have been observing and romanticizing Venus for more than 5,000 years. However, mapping its surface has nearly always been impossible, since the planet is shrouded in thick clouds. A breakthrough came just fifty years ago with the invention of radar imaging, leading to the discovery (and naming) of hundreds of new features in a relatively short length of time.

The rapid naming of Venus is a case study on the impact of planetary nomenclature — the process of naming features on other worlds. While the act of naming streamlines communication and humanizes alien landscapes, it is subject to bias, …

Galfit-Ing Agn Host Galaxies In Cosmos: Hst Versus Subaru, Callum Dewsnap, Pauline Barmby, Sarah C. Gallagher, C. Megan Urry, Aritra Ghosh, Meredith C. Powell

Physics and Astronomy Publications

The COSMOS field has been extensively observed by most major telescopes, including Chandra, HST, and Subaru. HST imaging boasts very high spatial resolution and is used extensively in morphological studies of distant galaxies. Subaru provides lower spatial resolution imaging than HST but a substantially wider field of view with greater sensitivity. Both telescopes provide near-infrared imaging of COSMOS. Successful morphological fitting of Subaru data would allow us to measure morphologies of over 104 known active galactic nucleus (AGN) hosts, accessible through Subaru wide-field surveys, currently not covered by HST. The morphological parameters indicate the types of galaxies that host AGNs. …

Nearby Galaxies: Modelling Star Formation Histories And Contamination By Unresolved Background Galaxies, Hadi Papei

Electronic Thesis and Dissertation Repository

Galaxies are complex systems of stars, gas, dust, and dark matter which evolve over billions of years, and one of the main goals of astrophysics is to understand how these complex systems form and change. Measuring the star formation history of nearby galaxies, in which thousands of stars can be resolved individually, has provided us with a clear picture of their evolutionary history and the evolution of galaxies in general.

In this work, we have developed the first public Python package, SFHPy, to measure star formation histories of nearby galaxies using their colour-magnitude diagrams. In this algorithm, an observed colour-magnitude …

Effects Of Silicon Dioxide As The Polar Dielectric On The Infrared Absorption Spectrum Ofthemetal-Insulator-Metal Metasurface, Ahmad K. Jafari, Matthew Gaddy, Imtiaz Ahmad, Satya R. Kachiraju, M D. Borhan Mia, Ishtiaque Ahmed, Sergey Nikishin, Myoung-Hwan Kim, Ayrton A. Bernussi

Physics and Astronomy Faculty Publications and Presentations

Metal-insulator-metal metasurfaces have been widely used as high-performance absorbers in almost all electromagnetic spectral ranges. Their absorption spectra can be engineered by making variations in the geometry of the unit cells and/or by embedding materials with specific optical constants. Including a polar dielectric in their structure is another approach for manipulating their absorption spectra. In this research, we have numerically and experimentally investigated the effect of using silicon dioxide (SiO2) as a polar dielectric on the absorption spectrum of a metal-insulator-metal metasurface composed of a tri-layer of Ni-SiO2-Ni. Our results have shown the presence of …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.