Observations Of Ion Density And Temperature Around The International Space Station During Two Geomagnetic Storms,
2018
University of New Hampshire, Durham
Observations Of Ion Density And Temperature Around The International Space Station During Two Geomagnetic Storms, Alex M. Wright
Honors Theses and Capstones
The International Space Station (ISS) is a low Earth orbit research facility and host to an international crew. Geomagnetic storms cause changes in the Earth’s magnetic field and affect the ion density and temperature in the ionosphere which could pose a hazard to ISS crew. This hazard is measured by the Floating Potential Measurement Unit (FPMU) which measures ion density, ion temperature, and the charge differential of the ISS relative to its surrounding environment. I analyzed data collected by Narrow Sweep Langmuir Probe for two storms in 2015. Ion density and temperature were affected by geomagnetic storms, but the effects …
Correlation Between Emission Lines And Radio Luminosities Of Active Galactic Nuclei,
2018
University of Kentucky
Correlation Between Emission Lines And Radio Luminosities Of Active Galactic Nuclei, Jessica Short-Long
Theses and Dissertations--Physics and Astronomy
Radio-loud active galactic nuclei (AGN) are one class of objects associated with accretion activity onto supermassive black holes in centers of massive galaxies. They are believed to be in a radiatively-inefficient accretion mode with low accretion rate. To understand this accretion mode, it is important to measure its radiative output at high energies (> 13.6eV), which can be traced through optical emission lines. However, little is known about their true radiative output. This is because no correlation between optical emission-line and radio luminosity has been found for the majority of low-luminosity radio AGN, which are often classified as low-excitation radio …
Magnetic Field Design To Reduce Systematic Effects In Neutron Electric Dipole Moment Measurements,
2018
University of Kentucky
Magnetic Field Design To Reduce Systematic Effects In Neutron Electric Dipole Moment Measurements, James Ryan Dadisman
Theses and Dissertations--Physics and Astronomy
Charge-Conjugation (C) and Charge-Conjugation-Parity (CP) Violation is one of the three Sakharov conditions to explain via baryogenesis the observed baryon asymmetry of the universe (BAU). The Standard Model of particle physics (SM) contains sources of CP violation, but cannot explain the BAU. This motivates searches for new physics beyond the standard model (BSM) which address the Sakharov criteria, including high-precision searches for new sources of CPV in systems for which the SM contribution is small, but larger effects may be present in BSM theories. A promising example is the search for the electric dipole moment of the neutron (nEDM), which …
Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars,
2018
CUNY City College
Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel
Dissertations and Theses
Asteroid bombardment contributed to extensive melting and resurfacing of ancient (> 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na2O + K2O) and …
Energy From Active Galactic Nuclei And The Effects On Host Spiral Galaxies,
2017
University of Arkansas, Fayetteville
Energy From Active Galactic Nuclei And The Effects On Host Spiral Galaxies, Amanda Schilling
Graduate Theses and Dissertations
I have investigated the energy output of active galactic nuclei (AGN) in order to understand how these objects evolve and the impact they may have on host galaxies. First, I looked at a sample of 96 AGN at redshifts $z \sim 2, 3,$ and $4$ which have imaging and thus luminosity measurements in the $griz$ and $JHK$ observed wavebands. For these galaxies, I have co-epochal data across those bands which accounted for variability in AGN luminosity. I used the luminosity measurements in the five bands to construct spectral energy distributions (SED) in the emitted optical-UV bands for each AGN. I …
Ion-Scale Wave Properties And Enhanced Ion Heating Across The Low-Latitude Boundary Layer During Kelvin-Helmholtz Instability,
2017
Embry-Riddle Aeronautical University
Ion-Scale Wave Properties And Enhanced Ion Heating Across The Low-Latitude Boundary Layer During Kelvin-Helmholtz Instability, T. W. Moore, K. Nykyri, A. P. Dimmock
Publications
In the Earth's magnetosphere, the magnetotail plasma sheet ions are much hotter than in the shocked solar wind. On the dawn sector, the cold-component ions are more abundant and hotter by 30–40% when compared to the dusk sector. Recent statistical studies of the flank magnetopause and magnetosheath have shown that the level of temperature asymmetry of the magnetosheath is unable to account for this, so additional physical mechanisms must be at play, either at the magnetopause or plasma sheet that contributes to this asymmetry. In this study, we perform a statistical analysis on the ion-scale wave properties in the three …
Physoon - Radiation Detection In Various High Altitude Environments,
2017
DePaul University
Physoon - Radiation Detection In Various High Altitude Environments, Christopher Helmerich
2017 Academic High Altitude Conference
Physoon is a high altitude ballooning payload designed and built by members of the Space Hardware Club for the purpose of comparing cosmic and terrestrial radiation from a variety of environmental conditions, including clear days, night times, solar events (eclipses, solar flares, coronal mass ejections), and thunderstorms. Over three design iterations, Physoon has flown eleven times with various combinations of Geiger counters sensors: a low energy Alpha-Beta-Gamma detector, an unshielded high-energy Beta-Gamma detector, and a shielded high-energy Beta-Gamma detector. One of these iterations successfully recovered data from high altitude during totality of the Great American Solar Eclipse. Another iteration was …
On The Dawn-Dusk Asymmetry Of The Kelvin-Helmholtz Instability Between 2007 And 2013,
2017
Embry-Riddle Aeronautical University
On The Dawn-Dusk Asymmetry Of The Kelvin-Helmholtz Instability Between 2007 And 2013, Z. W. Henry, K. Nykyri, T. W. Moore, A. P. Dimmock, X. Ma
Publications
Using data from Time History of Events and Macroscale Interactions during Substorms (THEMIS), a statistical study was performed to determine whether a dawn-dusk asymmetry exists in the occurrence rates of the Kelvin-Helmholtz (KH) instability during Parker-Spiral (PS) and Ortho-Parker-Spiral (OPS) orientations of the interplanetary magnetic field (IMF). It is determined from the data that there is a strong preference toward the dawn side during PS orientation, and although a preference to the dusk side during OPS is suggested, this requires further study for an unambiguous confirmation. The uncertainty in the OPS result is due to a low number of events …
Martian Cave Air-Movement Via Helmholtz Resonance,
2017
U.S. Geological Survey
Martian Cave Air-Movement Via Helmholtz Resonance, Kaj E. Williams, Timothy N. Titus, Chris H. Okubo, Glen E. Cushing
International Journal of Speleology
Infrasonic resonance has previously been measured in terrestrial caves by other researchers, where Helmholtz resonance has been suggested as the plausible mechanism resulting in periodic wind reversals within cave entrances. We extend this reasoning to possible Martian caves, where we examine the characteristics of four atypical pit craters (APCs) on Tharsis, suggested as candidate cave entrance locations. The results show that, for several possible cave air movement periods, we are able to infer the approximate cave volumes. The utility of inferring cave volumes for planetary cave exploration is discussed.
The Capabilities Of The Geostationary Operational Environmental Satellite-16 (Goes-16),
2017
Embry-Riddle Aeronautical University
The Capabilities Of The Geostationary Operational Environmental Satellite-16 (Goes-16), Brandon M. Kane
Student Works
This report investigates the capability of the new Geostationary Operational Environmental Satellite-16 (GOES-16) satellite to display 16 channels of the electromagnetic spectrum, to produce images at a higher resolution at increased intervals, and to detect and display lightning. This report also discusses the main instrumentation aboard the new geostationary satellite and how it aids in creating accurate data collection, which in turn, produces quicker weather forecasts and warnings. The 16 different channels produced by the Advanced Baseline Imager aboard the new satellite are analyzed in detail as to the functions and wavelengths on which the channels operate. The image resolution …
Influence Of Velocity Fluctuations On The Kelvin-Helmholtz Instability And Its Associated Mass Transport,
2017
Embry-Riddle Aeronautical University
Influence Of Velocity Fluctuations On The Kelvin-Helmholtz Instability And Its Associated Mass Transport, Katariina Nykyri, Xuanye Ma, Andrew Dimmock, Claire Foullon, Antonius Otto, Adnane Osmane
Publications
Kelvin-Helmholtz instability (KHI) and associated magnetic reconnection and diffusion processes provide plasma transport from solar wind into the magnetosphere. The efficiency of this transport depends on the magnetosheath and magnetospheric plasma and field properties at the vicinity of the magnetopause. Our recent statistical study using data from the Time History of Events and Macroscale Interactions during Substorms spacecraft indicates that the amplitude of the magnetosheath velocity fluctuations perpendicular to the magnetopause can be substantial. We have performed a series of local macroscale 2.5-dimensional magnetohydrodynamic simulations of the KHI during strongly northward interplanetary magnetic field and with the initial plasma parameters …
Temperature Variations In The Dayside Magnetosheath And Their Dependence On Ion-Scale Magnetic Structures: Themis Statistics And Measurements By Mms,
2017
Aalto University
Temperature Variations In The Dayside Magnetosheath And Their Dependence On Ion-Scale Magnetic Structures: Themis Statistics And Measurements By Mms, A. P. Dimmock, A. Osmane, T. I. Pulkkinen, K. Nykyri, E. Kilpua
Publications
The magnetosheath contains an array of waves, instabilities, and nonlinear magnetic structures which modify global plasma properties by means of various wave-particle interactions. The present work demonstrates that ion-scale magnetic field structures (∼0.2–0.5 Hz) observed in the dayside magnetosheath are statistically correlated to ion temperature changes on orders 10–20% of the background value. In addition, our statistical analysis implies that larger temperature changes are in equipartition to larger amplitude magnetic structures. This effect was more pronounced behind the quasi-parallel bow shock and during faster solar wind speeds. The study of two separate intervals suggests that this effect can result from …
Shape Modeling And Boulder Napping Of Asteroid 1992 Uy4.,
2017
University of Louisville
Shape Modeling And Boulder Napping Of Asteroid 1992 Uy4., Nicholas D Duong
College of Arts & Sciences Senior Theses
In August 2005, the near-Earth Asteroid 1992 UY4 made a close flyby, coming within 0.04 au of our planet. Between the dates of 1-10 August 2005, it was observed via delay-Doppler radar imaging by the Arecibo Observatory (2380 MHz, 13 cm) and the DSS-14 antenna at the Goldstone Deep Space Communications Complex (8560 MHz, 3.5 cm). The images achieve a resolution as fine as 7.5 m/pixel and reveal a lumpy and modestly asymmetric object. The images also revealed the presence of numerous large boulders/blocks on the surface of 1992 UY4. By using the modeling software SHAPE, which is standard in …
Imf Dependence Of Energetic Oxygen And Hydrogen Ion Distributions In The Near-Earth Magnetosphere,
2017
Chinese Academy of Sciences
Imf Dependence Of Energetic Oxygen And Hydrogen Ion Distributions In The Near-Earth Magnetosphere, H. Luo, E. A. Kronberg, K. Nykyri, K. J. Trattner, P. W. Daly, G. X. Chen, A. M. Du, Y. S. Ge
Publications
Energetic ion distributions in the near-Earth plasma sheet can provide important information for understanding the entry of ions into the magnetosphere and their transportation, acceleration, and losses in the near-Earth region. In this study, 11 years of energetic proton and oxygen observations (> ~274 keV) from Cluster/Research with Adaptive Particle Imaging Detectors were used to statistically study the energetic ion distributions in the near-Earth region. The dawn-dusk asymmetries of the distributions in three different regions (dayside magnetosphere, near-Earth nightside plasma sheet, and tail plasma sheet) are examined in Northern and Southern Hemispheres. The results show that the energetic ion distributions …
Fast-Moving Diffuse Auroral Patches: A New Aspect Of Daytime Pc3 Auroral Pulsations,
2017
Merrimack College
Fast-Moving Diffuse Auroral Patches: A New Aspect Of Daytime Pc3 Auroral Pulsations, Tetsuo Motoba, Yusuke Ebihara, Akira Kadokura, Mark J. Engebretson, Marc R. Lessard, Allan T. Weatherwax, Andrew J. Gerrard
Physics Faculty Publications
Auroral pulsations are a convenient diagnostic of wave-particle interactions in the magnetosphere. A case study of a daytime Pc3 (22–100 mHz) auroral pulsation event, measured with a ~2 Hz sampling all-sky camera at South Pole Station (74.4°S magnetic latitude) on 17 May 2012, is presented. The daytime Pc3 auroral pulsations were most active in a closed field line region where the aurora was dominated by diffuse green-line emissions and within ±2 h of magnetic local noon. Usually, but not always, the corresponding periodic variations were recorded with a colocated search coil magnetometer. Of particular interest is the two-dimensional auroral signature, …
Using Student Characteristics, Student Spatial-Content Knowledge, And Teacher Spatial-Content Knowledge To Predict Student Spatial-Content Knowledge Of Lunar Phases,
2017
University of Kentucky
Using Student Characteristics, Student Spatial-Content Knowledge, And Teacher Spatial-Content Knowledge To Predict Student Spatial-Content Knowledge Of Lunar Phases, Kyle A. Curry
Theses and Dissertations--Science, Technology, Engineering, and Mathematics (STEM) Education
Student demographic characteristics of gender and race/ethnicity, students’ spatial-content knowledge as measured by pre-instructional performance on the Lunar Phases Concept Inventory (LPCI) (Lindell & Olsen), and post-instructional performance on the Purdue Visualization of Rotations Test (PSVT) (Bodner & Guay, 1997), and teachers’ spatial-content knowledge as measured by the two assessments were considered to predict students’ overall understanding of lunar phases as measured by post-instructional results on the LPCI. A mixed modeling approach was used in a hierarchal manner to evaluate the student learning outcomes. Results showed that student gender was not a significant predictor of post-instructional student performance, but students …
Rethinking The Polar Cap: Eccentric Dipole Structuring Of Ulf Power At The Highest Corrected Geomagnetic Latitudes,
2016
Merrimack College
Rethinking The Polar Cap: Eccentric Dipole Structuring Of Ulf Power At The Highest Corrected Geomagnetic Latitudes, Kevin D. Urban, Andrew J. Gerrard, Louis J. Lanzerotti, Allan T. Weatherwax
Physics Faculty Publications
The day-to-day evolution and statistical features of Pc3-Pc7 band ultralow frequency (ULF) power throughout the southern polar cap suggest that the corrected geomagnetic (CGM) coordinates do not adequately organize the observed hydromagnetic spatial structure. It is shown that that the local-time distribution of ULF power at sites along CGM latitudinal parallels exhibit fundamental differences and that the CGM latitude of a site in general is not indicative of the site's projection into the magnetosphere. Thus, ULF characteristics observed at a single site in the polar cap cannot be freely generalized to other sites of similar CGM latitude but separated in …
Examination Of Resonant Modes In Microwave Cavities,
2016
Embry-Riddle Aeronautical University
Examination Of Resonant Modes In Microwave Cavities, Sophia Schwalbe, Gianpaolo Carosi
Student Works
The Axion Dark Matter eXperiment (ADMX) looks to detect dark matter axion particles by using microwave cavities in a high magnetic eld to convert the axion's mass energy to a detectable photon. The photon frequency corresponds to the axion mass. Tuning elements in the cavities allow the resonant frequency to be changed but only certain modes couple to the axion. Interactions with additional resonant modes that do not couple to the axion cause unobservable regions in the frequency range. This research investigated new methods to move the additional resonant modes in order to observe these regions.
Galaxies Probing Galaxies At High Resolution: Co-Rotating Gas Associated With A Milky Way Analog At Z = 0.4,
2016
University of Wisconsin - Madison
Galaxies Probing Galaxies At High Resolution: Co-Rotating Gas Associated With A Milky Way Analog At Z = 0.4, Aleksandar M. Diamond-Stanic, Alison L. Coil, John Moustakas, Christy A. Tremonti, Paul H. Sell, Alexander J. Mendez, Ryan C. Hickox, Greg H. Rudnick
Dartmouth Scholarship
We present results on gas flows in the halo of a Milky-Way-like galaxy at z = 0.413 based on high-resolution spectroscopy of a background galaxy. This is the first study of circumgalactic gas at high spectral resolution toward an extended background source (i.e., a galaxy rather than a quasar). Using long-slit spectroscopy of the foreground galaxy, we observe spatially extended Hα emission with a circular rotation velocity v circ ≈ 270 km s−1. Using echelle spectroscopy of the background galaxy, we detect and absorption lines at an impact parameter ρ= 27 kpc that are blueshifted from systemic …
The Dawn–Dusk Asymmetry Of Ion Density In The Dayside Magnetosheath And Its Annual Variability Measured By Themis,
2016
Aalto University
The Dawn–Dusk Asymmetry Of Ion Density In The Dayside Magnetosheath And Its Annual Variability Measured By Themis, Andrew P. Dimmock, Tuija I. Pulkkinen, Adnane Osmane, Katariina Nykyri
Publications
The local and global plasma properties in the magnetosheath play a fundamental role in regulating solar wind–magnetosphere coupling processes. However, the magnetosheath is a complex region to characterise as it has been shown theoretically, observationally and through simulations that plasma properties are inhomogeneous, non-isotropic and asymmetric about the Sun-Earth line. To complicate matters, dawn–dusk asymmetries are sensitive to various changes in the upstream conditions on an array of timescales. The present paper focuses exclusively on dawn–dusk asymmetries, in particularly that of ion density. We present a statistical study using THEMIS data of the dawn–dusk asymmetry of ion density in the …
