Astrophysics and Astronomy Commons^™

Electrical Detection Of Current Generated Spin In Topological Insulator Surface States: Role Of Interface Resistance, C. H. Li, O. M. J. Van ‘T Erve, C. Yan, L. Li., B. T. Jonker

Faculty & Staff Scholarship

Current generated spin polarization in topological insulator (TI) surface states due to spin-momentum locking has been detected recently using ferromagnet/tunnel barrier contacts, where the projection of the TI spin onto the magnetization of the ferromagnet is measured as a voltage. However, opposing signs of the spin voltage have been reported, which had been tentatively attributed to the coexistence of trivial two-dimensional electron gas states on the TI surface which may exhibit opposite currentinduced polarization than that of the TI Dirac surface states. Models based on electrochemical potential have been presented to determine the sign of the spin voltage expected for …

Kelt-22ab: A Massive, Short-Period Hot Jupiter Transiting A Near-Solar Twin, J. Labadie-Bartz, J. E. Rodriguez, K. G. Stassun, D. R. Ciardi, K. Penev, M. C. Johnson, B. S. Gaudi, K. D. Colón, A. Bieryla, D. W. Latham, J. Pepper, K. A. Collins, P. Evans, H. Relles, R. J. Siverd, J. Bento, X. Yao, C. Stockdale, T.-G. Tan, G. Zhou, J. D. Eastman, M. D. Albrow, D. Bayliss, T. G. Beatty, P. Berlind, V. Bozza, M. L. Calkins, David H. Cohen, I. A. Curtis, G. A. Esquerdo, D. Feliz, B. J. Fulton, J. Gregorio, D. James, Eric L.N. Jensen, J. A. Johnson, S. A. Johnson, M. D. Joner, D. Kasper, J. F. Kielkopf, R. B. Kuhn, M. B. Lund, A. Malpas, M. Manner, N. Mccrady, K. K. Mcleod, T. E. Oberst, M. T. Penny, P. A. Reed, D. H. Sliski, D. C. Stephens, D. J. Stevens, S. Villanueva Jr., R. A. Wittenmyer, J. T. Wright, R. Zambelli

Physics & Astronomy Faculty Works

We present the discovery of KELT-22Ab, a hot Jupiter from the KELT-South survey. KELT-22Ab transits the moderately bright (V ~ 11.1) Sun-like G2V star TYC 7518-468-1. The planet has an orbital period of P = 1.3866529 ± 0.0000027 days, a radius of R_P = 1.285 ((+0.12)/(=0.071)) R_J, and a relatively large mass of M_P = 3.47 ((+0.15)/(=0.14)) M_J. The star has R_★ = 1.099 ((+0.079)/(=0.046)) R_⊙, M_★ = 1.092 ((+0.045)/(-0.041) M_⊙, T_eff = 5767 ((+50)/(-49) K, log g_★ = 4.393 ((+0.039)/(-0.060)) (cgs), and [m/H] = …

Reply To: “On The Understanding Of Current-Induced Spin Polarization Of Three-Dimensional Topological Insulators”, C. H. Li, O. M. J. Van ‘T Erve, S. Rajput, L. Li, B. T. Jonker

Faculty & Staff Scholarship

No abstract provided.

Exploring The Structure Of Misconceptions In The Force Concept Inventory With Modified Module Analysis, James Wells, Rachel Henderson, John Stewart, Gay Stewart, Jie Yang, Adrienne Traxler

Faculty & Staff Scholarship

Module analysis for multiple-choice responses (MAMCR) was applied to a large sample of Force Concept Inventory (FCI) pretest and post-test responses (Npre ¼ 4509 and Npost ¼ 4716) to replicate the results of the original MAMCR study and to understand the origins of the gender differences reported in a previous study of this dataset. When the results of MAMCR could not be replicated, a modification of the method was introduced, modified module analysis (MMA). MMA was productive in understanding the structure of the incorrect answers in the FCI, identifying 9 groups of incorrect answers on the pretest and 11 groups …

The Undeniable Attraction Of Lunar Swirls, Dany Waller

Posters-at-the-Capitol Presentations

Lunar swirls are complex patterns on the Moon with distinct brightness signatures and magnetic characteristics. Current research has suggested that the formation of lunar swirls relies on local magnetic fields to shield impinging solar wind, based on a shift in electromagnetic wavelength peaks related to solar radiation and space weathering. Our research combined recent models and methods to characterize these anomalies at the surface of the Moon, exploring the effects of field strength and position. We have produced a high resolution map of a famous swirl named Reiner Gamma using magnetic dipole modeling. These maps and models are considered when …

Tuning The Reactivity Of Nanoenergetic Gas Generators Based On Bismuth And Iodine Oxidizers, Mkhitar A. Hobosyan, Karen S. Martirosyan

Physics & Astronomy Faculty Publications

There is a growing interest on novel energetic materials called Nanoenergetic Gas- Generators (NGGs) which are potential alternatives to traditional energetic materials including pyrotechnics, propellants, primers and solid rocket fuels. NGGs are formulations that utilize metal powders as a fuel and oxides or hydroxides as oxidizers that can rapidly release large amount of heat and gaseous products to generate shock waves. The heat and pressure discharge, impact sensitivity, long term stability and other critical properties depend on the particle size and shape, as well as assembling procedure and intermixing degree between the components. The extremely high energy density and the …

Waveband Luminosity Correlations In Flux-Limited Multiwavelength Data, Jack Singal, V. Petrosian, Sami Malik, Jibran Haider

Physics Faculty Publications

We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with …

Finding Obscure Black Hole Growth Via Spectral Energy Distribution Modeling, Randall K. Chan

Honors Theses

An active galactic nucleus (AGN) occurs when the supermassive black hole at the center of the galaxy starts to grow. We still currently do not know what triggers AGN. Theories suggest that galaxy mergers could trigger AGNs, but past research has not been able to find a correlation between x-ray detected AGNs and disturbed galaxies. The present research looks specifically at AGN not detected in the x-ray, or obscured AGN. Using a newly updated IDL code, FAST, we were able to identify potential obscured AGN through spectral energy distribution (SED) modeling. We found a total of 526 obscured AGN in …

Ua1c2/86 Bell Observatory Photos, Wku Archives

WKU Archives Collection Inventories

Images of the Bell Observatory.

Unh Observatory Exoplanet Transit Depth Limit, Nicholas R. Larose

Honors Theses and Capstones

Using the University of New Hampshire Observatory, we performed multiple exoplanet transits observations on a variety of systems. Of these transits, those performed with ideal weather conditions were chosen to do extensive analysis on. The transit chosen for initial analysis was HAT-P-56b. We then used Z-Score values, along with the average mean and standard deviation collected from multiple transits to determine a minimum possible transit depth of 7.4 +/- 0.6 mmag. This value will allow UNH to access exoplanet transit observation and / or confirm potential exoplanets, thus making the UNH Observatory more research capable. A follow up threshold transit …

Charged Particle Filter For Entrance Of Imap-Lo, Daniel Abel

Honors Theses and Capstones

No abstract provided.

Determination Of Multi-Messenger Signals From Matter Outflows Of Merger Systems, Ronny Nguyen

Honors Theses and Capstones

In 2017, LIGO detected gravitational waves from GW170817. This presented for the first time, gravitational waves originating from a neutron star - neutron star merger. Studies of neutron star mergers are significant because the multi-messenger signals in the form of gravitational waves and electromagnetic waves can inform us on the nuclear physics of neutron stars and the creation of heavy elements in the universe. Matter is ejected in the merging process and forms the outflow which provides a neutron-rich environment for rapid neutron capture (r-process) to occur leading to the nucleosynthesis of heavy elements. What we detect on Earth are …

Electron Model Based On Helmholtz’S Electron Vortex Theory & Kolmogorov’S Theory Of Turbulence, Florentin Smarandache, Victor Christianto, Robert Neil Boyd

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper, we explore a new electron model based on Helmholtz’s electron vortex and Kolmogorov theory of turbulence. We also discuss a new model of origination of charge and matter.

Integrable Cosmological Model With Van Der Waals Gas And Matter Creation, Rossen Ivanov, Emil Prodanov

Articles

A cosmological model with van der Waals gas and dust has been studied in the context of a three-component autonomous non-linear dynamical system involving the time evolution of the particle number density, the Hubble parameter and the temperature. Due to the presence of a symmetry of the model, the temperature evolution law is determined (in terms of the particle number density) and with this the dynamical system reduces to a two-component one which is fully integrable. The globally conserved Hamiltonian is identified and, in addition to it, some special (second) integrals, defined and conserved on a lower-dimensional manifold, are found. …

The Gemini Planet Imager Exoplanet Survey: Giant Planet And Brown Dwarf Demographics From 10 To 100 Au, Eric L. Nielsen, Robert J. De Rosa, Bruce Macintosh, Jason J. Wang, Jean Baptiste Ruffio, Eugene Chiang, Mark S. Marley, Didier Saumon, Dmitry Savransky, S. Mark Ammons, Vanessa P. Bailey, Travis Barman, Célia Blain, Joanna Bulger, Adam Burrows, Jeffrey Chilcote, Tara Cotten, Ian Czekala, Rene Doyon, Gaspard Duchene, Thomas M. Esposito, Daniel Fabrycky, Michael P. Fitzgerald, Katherine B. Follette, Jonathan J. Fortney, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Sasha Hinkley, Lea A. Hirsch, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

We present a statistical analysis of the first 300 stars observed by the Gemini Planet Imager Exoplanet Survey. This subsample includes six detected planets and three brown dwarfs; from these detections and our contrast curves we infer the underlying distributions of substellar companions with respect to their mass, semimajor axis, and host stellar mass. We uncover a strong correlation between planet occurrence rate and host star mass, with stars M ∗ >1.5 M o more likely to host planets with masses between 2 and 13M Jup and semimajor axes of 3-100 au at 99.92% confidence. We fit a double power-law …

Performance Of The Gemini Planet Imager Non-Redundant Mask And Spectroscopy Of Two Close-Separation Binaries: Hr 2690 And Hd 142527, Alexandra Z. Greenbaum, Anthony Cheetham, Anand Sivaramakrishnan, Fredrik T. Rantakyrö, Gaspard Duchêne, Peter Tuthill, Robert J. De Rosa, Rebecca Oppenheimer, Bruce Macintosh, S. Mark Ammons, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Andrew Cardwell, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, James R. Graham, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, Quinn Konopacky, James E. Larkin, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

The Gemini Planet Imager (GPI) contains a 10-hole non-redundant mask (NRM), enabling interferometric resolution in complement to its coronagraphic capabilities. The NRM operates both in spectroscopic (integral field spectrograph, henceforth IFS) and polarimetric configurations. NRM observations were taken between 2013 and 2016 to characterize its performance. Most observations were taken in spectroscopic mode, with the goal of obtaining precise astrometry and spectroscopy of faint companions to bright stars. We find a clear correlation between residual wavefront error measured by the adaptive optic system and the contrast sensitivity by comparing phase errors in observations of the same source, taken on different …

High-Speed Distributed Data Process Of Photometric Astronomical Data, Paul Doyle

Other

Since the 1970s the CCD has been the principle method of measuring flux to calculate the apparent magnitude of celestial objects within astronomical photometry. Each CCD image must be digitally cleaned and calibrated prior to its use. As data archives increase in size to Petabytes, the data processing challenge requires image processing techniques to continue to exceed the rate of data capture.

This paper describes NIMBUS, a rapidly scalable, failure resilient distributed network architecture capable of processing CCD image data at a rate of hundreds of Terabytes per day. NIMBUS is implemented using a decentralized web queue to control the …

Multi-Band Optical And Near-Infrared Properties Of Faint Submillimeter Galaxies With Serendipitous Alma Detections, Pallavi Patil, Kristina Nyland, Mark Lacy, Duncan Farrah, José Afonso, Wayne A. Barkhouse, Jason Surace

Physics Faculty Publications

We present a catalog of 26 faint submillimeter galaxies (SMGs) in the XMM Large Scale Structure (XMM-LSS) field identified by cross-matching serendipitously detected sources in archival pre–Atacama Large Millimeter Array (ALMA) band 6 and 7 data with multiband near-infrared (NIR) and optical data from the Spitzer Extragalactic Representative Volume Survey, the VISTA Deep Extragalactic Survey, the Canada–France–Hawaii Telescope Legacy Large Survey, and the Hyper Suprime-Cam Subaru Strategic Program. Of the 26 SMGs in our sample, 15 are identified here for the first time. The majority of the sources in our sample (16/26) have faint submillimeter fluxes (0.1 mJy < S 1mm …

Differences Between High-Productive And Low-Productive Active Regions, Declan Brick

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Fragmented Brightest Cluster Galaxies, Andrew Guillory

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

The Discovery Of A Lifetime: Gravitational-Waves, Maria I Dominguez Barraza

Nebraska College Preparatory Academy: Senior Capstone Projects

This presentation offers an insight to one of the biggest discoveries made in science. The discovery of gravitational-waves had been a long journey to achieve for physicists and scientist. Now gravitational-waves are helping scientists study the universe in a more efficient way never seen before. The discovery of gravitational-waves is a sign that a new era of astronomy and physics is about to open doors for many scientists and astrophysicists.

● Gravitational-waves are energycarrying waves propagating through a gravitational field, produced when a massive body is accelerated or otherwise disturbed. ● Gravitational-waves prove the existence of Black Holes. ● Laser …

High-Order Finite-Difference Nonlinear Filter Methods For Subsonic Turbulence Simulation With Stochastic Forcing, Alexei G. Kritsuk, Dmitry Kotov, Bjorn Sjögreen, Helen C. Yee

United States National Aeronautics and Space Administration: Publications

Numerical stability of high-order fi lter schemes developed by Yee & Sjogreen is tested on thr~dimensional turbulence simulations with stochastic forcing and their performance is compared with that ofTVD and \VENO schemes. The bestperforming filter method employs an eighth-order central base scheme with the Kennedy & Gruber skew-symmetric splitting of the inviscid fttLx derivative, a wavelet-based local flow sensor, a nonlinear filter utilizing the dissipative portion of seventh-order \\'ENO scheme, and an explicit third- or fourth-order RungeKutta t ime integration. \Ve show that the filter scheme is more computational]y efficient and provides a wider spectral bandwidth compared to the seventh-order …

Asteroid Surfaces: The Importance Of Cohesive Forces, Keanna Jardine

Electronic Theses and Dissertations

Adhesive forces play a significant role on airless bodies due to their weak gravities. Investigating adhesion at the surface of asteroids and their constituent components is vital to understanding their formation and evolution. Previous research has been done to understand the interaction of micron-sized spheres to planar surfaces and sphere-to-sphere interactions, which have been used to develop models of asteroid surfaces. Our investigation experimentally investigates adhesion through atomic force microscopy (AFM) measurements between JSC-1 simulant particles and several AFM tips, including a typical pyramidal gold tip and microspheres of sizes 2 μm and 15 μm. The samples of JSC-1 consist …

Application Of Wavelet Analysis On Transient Rlectivity In Ultra-Thin Films, S. Yousefi Saraf, R. Trappen, S. Kumari, G. Bhandari, N. Mottaghi, C. Y. Huang, G. B. Cabrera, A. D. Bristow, M. B. Holcomb

Faculty & Staff Scholarship

Applications of wavelet analysis in ultra-thin film transient reflectivity (TR) measurements have been investigated. Advantages of utilizing different localized wavelet bases, in position and time, have been addressed on the residual TR signals. Morse wavelets have been used to obtain information from the abrupt oscillatory modes in the signal, which are not distinguishable with conventional methods such as Fourier transforms. These abrupt oscillatory modes are caused by the surface, interface, or any short-lived oscillatory modes which are suppressed in the TR signal in ultra-thin films. It is demonstrated that by choosing different Morse wavelets, information regarding different oscillatory modes in …

A Few Calculations Of Receding Moon From Spherical Kinetic Dynamics, Receding Planetary Orbits, And The Quantization Of Celestial Motions, Florentin Smarandache, Victor Christianto, Robert Neil Boyd

Branch Mathematics and Statistics Faculty and Staff Publications

The present article discusses some interesting phenomena including the Lense-Thirring type anomalous precession, using a known spherical kinetic dynamics approach. Other implications include a plausible revised version of the celestial quantization equation described by Nottale and Rubcic & Rubcic. If the proposition described herein corresponds to the facts, then this kinetic dynamics interpretation of ‘frame-dragging’ effect could be viewed as a step to unification between GTR-type phenomena and QM. Further observation to verify or refute this conjecture is recommended, plausibly using LAGEOS type satellites.

Analysis Of Autoguiding For Exoplanet Transit Research At The Unh Observatory, Anthony Cappuccio

Honors Theses and Capstones

This paper will discuss the proper calibration technique for an autoguider of a CCD camera and the results that follow from successful exoplanet transit observations. A brief background on exoplanets, the transit method, and the analysis of their parent stars through photometry will be examined. The results will be presented in a before and after framework that will visually represent the data improvements from autoguiding as graphical Light Curves (LC). The addition of being able to autoguide at the UNH observatory will work towards providing future students with the possibility of performing follow-up ground-based observations and archiving their work online …

Multidimensional Item Response Theory And The Force And Motion Conceptual Evaluation, Jie Yang, Cabot Zabriskie, John Stewart

Faculty & Staff Scholarship

Many studies have examined the structure and properties of the Force Concept Inventory (FCI); however, far less research has investigated the Force and Motion Conceptual Evaluation (FMCE). This study applied Multidimensional Item Response Theory (MIRT) to a sample of N ¼ 4528 FMCE post-test responses. Exploratory factor analysis showed that 5, 9, and 10-factor models optimized some fit statistics. The FMCE uses extensive blocking of items into groups with a common stem; these blocks factored together in most models. A confirmatory analysis, which constrained the MIRT models to a theoretical model constructed from expert solutions, produced a model requiring only …

Testing For Directionality In The Planck Polarization And Lensing Data, Majd Ghrear, Emory F. Bunn, Dagoberto Contreras, Douglas Scott

Physics Faculty Publications

In order to better analyse the polarization of the cosmic microwave background (CMB), which is dominated by emission from our Galaxy, we need tools that can detect residual foregrounds in cleaned CMB maps. Galactic foregrounds introduce statistical anisotropy and directionality to the polarization pseudo-vectors of the CMB, which can be investigated by using the D statistic of Bunn and Scott. This statistic is rapidly computable and capable of investigating a broad range of data products for directionality. We demonstrate the application of this statistic to detecting foregrounds in polarization maps by analysing the uncleaned Planck 2018 frequency maps. For the …

Galileo's Telescope, Christopher Sirola

Faculty Publications

One of the most consequential inventions of modern times is the telescope. Almost immediately upon turning it to the skies, Galileo made discoveries that altered our perceptions of our place in the cosmos forever: features on the Moon, the rotation of the Sun, the composition of the Milky Way, the phases of Venus, and the four large moons of Jupiter.

Improving Photometry And Astrophotography By Eliminating Dark Frames And Flat Fields, Tom C. Ireland

Honors Theses and Capstones

I report on the efforts to improve the dark frames and flat fielding procedure for the charged-coupled device (CCD) camera for the Celestron C14 telescope at the UNH observatory. Dark frames are images taken while the shutter of the camera is closed so that only electronic and dark noise and other internal inconsistencies are recorded. These are important because they allow astronomers to subtract out interference from dark current. Additionally, flat fields are images of the entire field of the telescope so that the brightness in the pixels of the telescope’s field of view is uniform. Flat fields are vital …