Astrophysics and Astronomy Commons^™

Normalization Of Leadville Neutron Monitor To Climax Neutron Monitor, Brian J. O'Connor

Honors Theses and Capstones

No abstract provided.

Multidimensional Item Response Theory And The Conceptual Survey Of Electricity And Magnetism, Cabot Zabriskie, John Stewart

Faculty & Staff Scholarship

This paper is part of the Focused Collection on Quantitative Methods in PER: A Critical Examination.] While many studies have examined the structure, validity, and reliability of the Force Concept Inventory, far less research has been performed on other conceptual instruments in widespread use in physics education research. This study performs a confirmatory analysis of the Conceptual Survey of Electricity and Magnetism (CSEM) guided by a theoretical model of expert understanding of electricity and magnetism. Multidimensional Item Response Theory (MIRT) with the discrimination matrix constrained to the theoretical model was used to investigate two large datasets (N1=2014 and N2=2657) from …

Partitioning The Gender Gap In Physics Conceptual Inventories: Force Concept Inventory, Force And Motion Conceptual Evaluation, And Conceptual Survey Of Electricity And Magnetism, Rachel Henderson, John Stewart, Adrienne Traxler

Faculty & Staff Scholarship

Over the last decade, the “gender gap” in physics conceptual inventory scores has been extensively studied by the physics education research community. Researchers have identified many factors that influence the overall differences in post-test scores between men and women. More recently, it has been shown that the Force Concept Inventory (FCI) contains eight items that are substantially unfair; six are unfair to women, two are unfair to men. The Force and Motion Conceptual Evaluation (FMCE) and the Conceptual Survey of Electricity and Magnetism (CSEM), however, contain fewer unfair items. In this work, results from prior studies are used to further …

Interface Engineered Room‐Temperature Ferromagnetic Insulating State In Ultrathin Manganite Films, Weiwei Li, Bonan Zhu, Qian He, Albina Y. Borisevich, Chao Yun, Rui Wu, Ping Lu, Zhimin Qi, Qiang Wang, Aiping Chen, Haiyan Wang, Stuart A. Cavill, Kelvin H.L. Zhang, Judith L. Macmanus-Driscoll

Faculty & Staff Scholarship

emperatures near room temperature are critically needed for use in dissipationless quantum computation and spintronic devices. However, such materials are extremely rare. Here, a room‐temperature FMI is achieved in ultrathin La0.9Ba0.1MnO3 films grown on SrTiO3 substrates via an interface proximity effect. Detailed scanning transmission electron microscopy images clearly demonstrate that MnO6 octahedral rotations in La0.9Ba0.1MnO3 close to the interface are strongly suppressed. As determined from in situ X‐ray photoemission spectroscopy, O K‐edge X‐ray absorption spectroscopy, and density functional theory, the realization of the FMI state arises from a reduction of Mn eg bandwidth caused by the quenched MnO6 octahedral …

Automated Polarization-Dependent Multidimensional Coherent Spectroscopy Phased Using Transient Absorption, J. K. Wahlstrand, G. M. Wernsing, J. Paul, A. D. Bristow

Faculty & Staff Scholarship

: An experimental apparatus is described for multidimensional optical spectroscopy with fully automated polarization control, based on liquid crystal variable retarders. Polarization dependence of rephasing two-dimensional coherent spectra are measured in a single scan, with absolute phasing performed for all polarization configurations through a single automated auxiliary measurement at the beginning of the scan. A factor of three improvement in acquisition time is demonstrated, compared to the apparatus without automated polarization control. Results are presented for a GaAs quantum well sample and an InGaAs quantum well embedded in a microcavity

Micro/Nanofabrication And Characterization Of Advanced Materials And Devices, Yanxi Li, Liang He, Mengyu Yan, Zhengjun Wang

Faculty & Staff Scholarship

No abstract provided.

Lower Atmosphere And Pressure Evolution On Pluto From Ground-Based Stellar Occultations, 1988-2016, E. Meza, B. Sicardy, M. Assafin, J. L. Ortiz

University Faculty Publications and Creative Works

Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft. Aims. The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015. Methods. Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ∼5 and ∼380 km …

How To Celebrate 24 New Year's Eves In A Single Year!, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

New Year's Eve 2018 reaches me on Jeju Island, South Korea, in the East China Sea. While I had spent New Year's Eve 2017 in Galapagos Islands, in the Pacific. We can celebrate 24 New Year's Eves in a single year, moving to the West – for example in an orbital spacecraft - (in the reverse sense of Earth's rotation around its axis) at a faster angular speed than Earth's rotation, jumping from one time-zone to another, and starting from the International Date Line. { In this paper we are referring to the solar day, hence to the angular speed …

The Encyclopedia Of Neutrosophic Researchers - Vol. 3, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This is the third volume of the Encyclopedia of Neutrosophic Researchers, edited from materials offered by the authors who responded to the editor’s invitation. The authors are listed alphabetically. The introduction contains a short history of neutrosophics, together with links to the main papers and books. Neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics, neutrosophic measure, neutrosophic precalculus, neutrosophic calculus and so on are gaining significant attention in solving many real life problems that involve uncertainty, impreciseness, vagueness, incompleteness, inconsistent, and indeterminacy. In the past years the fields of neutrosophics have been extended and applied in various fields, such as: …

Neutrosophic Triplet Structures - Vol. 1, Florentin Smarandache, Memet Sahin

Branch Mathematics and Statistics Faculty and Staff Publications

Neutrosophic set has been derived from a new branch of philosophy, namely Neutrosophy. Neutrosophic set is capable of dealing with uncertainty, indeterminacy and inconsistent information. Neutrosophic set approaches are suitable to modeling problems with uncertainty, indeterminacy and inconsistent information in which human knowledge is necessary, and human evaluation is needed. Neutrosophic set theory was firstly proposed in 1998 by Florentin Smarandache, who also developed the concept of single valued neutrosophic set, oriented towards real world scientific and engineering applications. Since then, the single valued neutrosophic set theory has been extensively studied in books and monographs, the properties of neutrosophic sets …

Exomol Line List - Xxxiv. A Rovibrational Line List For Phosphinidene (Ph) In Its X³Σ¯ And A¹Δ Electronic States, Jonathan Langleben, Jonathan Tennyson, Sergei N. Yurchenko, Peter Bernath

Chemistry & Biochemistry Faculty Publications

A rovibronic line list for the ground (X³Σ⁻) and first excited (a¹Δ) states of phosphinidene, ³¹PH, is computed. The line list is designed for studies of exoplanetary and cool stellar atmospheres with temperatures up to 4000 K. A combination of empirical and ab initio data is used to produce the line list: potential energy curves (PECs) are fitted using experimental transition frequencies; these transitions are reproduced with a root mean square error of 0.01 cm⁻¹. The nuclear Schrödinger equation is solved using these PECs plus Born–Oppenheimer and spin splitting correction terms. …

Tests Of General Relativity With Gw170817, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Robert Stone, D. Tuyenbayev, W. H. Wang

Physics & Astronomy Faculty Publications

The recent discovery by Advanced LIGOand AdvancedVirgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large …

On The New Concept Creatio Ex-Rotatione, Florentin Smarandache, Victor Christianto

Branch Mathematics and Statistics Faculty and Staff Publications

It is known that the Big Bang theory was based on the concept of creation ex nihilo, after ancient Greek philosophers. In this paper, we discuss the concept of creatio ex nihilo, as well as two other approaches - Intelligent Design and Emergence Theory. We argue that beside the above three approaches, a new concept called creatio ex-rotatione offers a resolution to the long standing disputes between beginning and eternity of the Universe. We agree with Vaas: [h]ow a conceptual and perhaps physical solution of the temporal aspect of Immanuel Kant’s “first antinomy of pure reason” is possible, i.e., how …

Using Coherence To Improve The Calculation Of Active Acoustic Intensity With The Phase And Amplitude Gradient Estimator Method, Mylan Ray Cook

Theses and Dissertations

Coherence, which gives the similarity of signals received at two microphone locations, can be a powerful tool for calculating acoustic quantities, particularly active acoustic intensity. To calculate active acoustic intensity, a multi-microphone probe is often used, and therefore coherence between all microphone pairs on the probe can be obtained. The phase and amplitude gradient estimator (PAGE) method can be used to calculate intensity, and is well suited for many situations. There are limitations to this method—such as multiple sources or contaminating noise in the sound field—which can cause significant error. When there are multiple sources or contaminating noise present, the …

The Polarization Mode Of The Auroral Radio Emission From The Early-Type Star Hd 142301, P. Leto, C. Trigilio, Lidi M. Oskinova, Richard Ignace, C. S. Buemi, G. Umana, F. Cavallaro, A. Ingallinera, F. Bufano, N. M. Phillips, C. Agliozzo, L. Cerrigone, H. Todt, S. Riggi, F. Leone

ETSU Faculty Works

We report the detection of the auroral radio emission from the early-type magnetic star HD 142301. New VLA observations of HD 142301 detected highly polarized amplified emission occurring at fixed stellar orientations. The coherent emission mechanism responsible for the stellar auroral radio emission amplifies the radiation within a narrow beam, making the star where this phenomenon occurs similar to a radio lighthouse. The elementary emission process responsible for the auroral radiation mainly amplifies one of the two magneto-ionic modes of the electromagnetic wave. This explains why the auroral pulses are highly circularly polarized. The auroral radio emission of HD 142301 …

Asymmetric Shapes Of Radio Recombination Lines From Ionized Stellar Winds, Richard Ignace

ETSU Faculty Works

Recombination line profile shapes are derived for ionized spherical stellar winds at radio wavelengths. It is assumed that the wind is optically thick owing to free-free opacity. Emission lines of arbitrary optical depth are obtained assuming that the free-free photosphere forms in the outer, constant expansion portion of the wind. Previous works have derived analytic results for isothermal winds when the line and continuum source functions are equal. Here, semi-analytic results are derived for unequal source functions to reveal that line shapes can be asymmetric about line center. A parameter study is presented and applications discussed.

Measurement Of Nuclear Transparency Ratios For Protons And Neutrons, M. Duer, O. Hen, E. Piasetzky, L. B. Weinstein, A. Schmidt, I. Korover, E. O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinski, A. S. Biselli, S. Boiarinov, W. J. Briscoe, X. Zheng, Et Al., The Clas Collaboration

Physics Faculty Publications

This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e, e'n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted in two kinematical regions, corresponding to knockout of mean-field nucleons and to the breakup of Short-Range Correlated nucleon pairs. The extracted neutron transparency ratios are consistent with each other for the two measured kinematical regions and agree with the proton transparencies extracted from new and previous (e, e'p) measurements, including those from neutron-rich nuclei such as lead. The data also agree with and …

Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato

Physics Faculty Publications

Motivated by recently observed tension between O(α²_s) calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through an O(α²_s) transversely differential cross section. The results confirm earlier calculations, and provide further support to the observation that tension exists with current parton distribution and fragmentation functions.

Skew-Symmetric Splitting Of High-Order Central Schemes With Nonlinear Filters For Computational Aeroacoustics Turbulence With Shocks, Bjorn Sjögreen, Helen C. Yee, Alan A. Wray

United States National Aeronautics and Space Administration: Publications

A class of high-order nonlinear filter schemes by Yee et al. (J Comput Phys 150:199–238, 1999), Sjögreen and Yee (J Comput Phys 225:910–934, 2007), and Kotov et al. (Commun Comput Phys 19:273–300, 2016; J Comput Phys 307:189–202, 2016) is examined for long-time integrations of computational aeroacoustics (CAA) turbulence applications. This class of schemes was designed for an improved nonlinear stability and accuracy for long-time integration of compressible direct numerical simulation and large eddy simulation computations for both shock-free turbulence and turbulence with shocks. They are based on the skew-symmetric splitting version of the high-order central base scheme in conjunction with …

Location, Orbit And Energy Of A Meteoroid Impacting The Moon During The Lunar Eclipse Of January 21, 2019 & Testing The Weak Equivalence Principle With Cosmological Gamma Ray Bursts, Matipon Tangmatitham

Dissertations, Master's Theses and Master's Reports

Location, orbit and energy of a meteoroid impacting the moon during the Lunar Eclipse of January 21, 2019

During the total lunar eclipse of January 21, 2019 at least two meteoroids impacted the moon producing visible flash lights on the near side. One of the impacts occurred on the darkest side of the visible lunar face and was witnessed by many astrophotographers. In this paper we present estimations of the location, impact parameters (velocity and incoming direction), orbit and energy of the meteoroid, as obtained from images and videos collected by amateur astronomers in Colombia, the Dominican Republic, Morocco, USA, …

Eigenstates Transition Without Undergoing An Adiabatic Process, Fatemeh Mostafavi, Luqi Yuan, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

We introduce a class of non-Hermitian Hamiltonians that offers a dynamical approach to a shortcut to adiabaticity (DASA). In particular, in our proposed 2 × 2 Hamiltonians, one eigenvalue is absolutely real and the other one is complex. This specific form of eigenvalues helps us to exponentially decay the population in an undesired eigenfunction or amplify the population in the desired state while keeping the probability amplitude in the other eigenfunction conserved. This provides us with a powerful method to have a diabatic process with the same outcome as its corresponding adiabatic process. In contrast to standard shortcuts to adiabaticity, …

Viewing The Eclipse From 109,000 Feet And The Road To Get There, Kendra Sibbernsen, Michael Sibbernsen

Department of Physics and Astronomy: Faculty Publications

The NASA Nebraska High Altitude Ballooning Program was one of 55 teams across the nation to fly weather balloons within the August 21st Total Solar Eclipse and stream live video to the internet. On this day, the Nebraska team launched three high altitude balloons to take scientific measurements and take photos and video ofthe Moon's shadow falling on the Earth. These balloons included the NASA common video streaming payload as well as experiments from students at Metropolitan Community College and from faculty and students at Omaha Public Schools. The launches took place at the "Gem Over the Prairie" event at …

Properties Of The Binary Neutron Star Merger Gw170817, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Robert Stone, Darkhan Tuyenbayev, Wenhui Wang

Physics & Astronomy Faculty Publications

On August 17, 2017, the Advanced LIGO and Advanced Virgo gravitational-wave detectors observed a low-mass compact binary inspiral. The initial sky localization of the source of the gravitational-wave signal, GW170817, allowed electromagnetic observatories to identify NGC 4993 as the host galaxy. In this work, we improve initial estimates of the binary's properties, including component masses, spins, and tidal parameters, using the known source location, improved modeling, and recalibrated Virgo data. We extend the range of gravitational-wave frequencies considered down to 23 Hz, compared to 30 Hz in the initial analysis. We also compare results inferred using several signal models, which …

Constraining The P-Mode–G-Mode Tidal Instability With Gw170817, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, D. Tuyenbayev, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Robert Stone, W. H. Wang

Physics & Astronomy Faculty Publications

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy fromthe orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral.We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnBpg !pg) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models …

All-Sky Search For Long-Duration Gravitational-Wave Transients In The Second Advanced Ligo Observing Run, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Malik Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny

Physics & Astronomy Faculty Publications

We present the results of a search for long-duration gravitational-wave transients in the data from the Advanced LIGO second observation run; we search for gravitational-wave transients of 2–500 s duration in the 24–2048 Hz frequency band with minimal assumptions about signal properties such as waveform morphologies, polarization, sky location or time of occurrence. Signal families covered by these search algorithms include fallback accretion onto neutron stars, broadband chirps from innermost stable circular orbit waves around rotating black holes, eccentric inspiral-merger-ringdown compact binary coalescence waveforms, and other models. The second observation run totals about 118.3 days of coincident data between November …

The Impact Of Hii Regions On The Interstellar Medium Of Our Galaxy, Matteo Luisi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The interstellar medium (ISM) of our Galaxy contains low-density diffuse ionized gas known as the warm ionized medium (WIM). O- and B-type stars emit large amounts of ionizing radiation and it is believed that a fraction of this radiation escapes from their fully ionized HII regions and into the ISM where it is responsible for maintaining the ionization of the WIM. Here we aim to better understand how the radiation produced by OB stars is able to leak from the HII regions, how the radiation field changes during this process, and how the radiation affects the ambient ISM. Using Green …

Reproducible K-Means Clustering In Galaxy Feature Data From The Gama Survey, Sebastian Turner, Lee S. Kelvin, Ivan K. Baldry, Paulo J. Lisboa, Steven N. Longmore, Chris A. Collins, Benne W. Holwerda, Andrew M. Hopkins, Jochen Liske

Faculty and Staff Scholarship

A fundamental bimodality of galaxies in the local Universe is apparent in many of the features used to describe them. Multiple sub-populations exist within this framework, each representing galaxies following distinct evolutionary pathways. Accurately identifying and characterizing these sub-populations requires that a large number of galaxy features be analysed simultaneously. Future galaxy surveys such as LSST and Euclid will yield data volumes for which traditional approaches to galaxy classification will become unfeasible. To address this, we apply a robust k-means unsupervized clustering method to feature data derived from a sample of 7338 local-Universe galaxies selected from the Galaxy And Mass …

Askap Commissioning Observations Of The Gama 23 Field, Denis A. Leahy, A. M. Hopkins, R. P. Norris, J. Marvil, J. D. Collier, E. N. Taylor, J. R. Allison, C. Anderson, M. Bell, M. Bilicki, J. Bland-Hawthorn, S. Brough, M. J.I. Brown, S. Driver, G. Gurkan, L. Harvey-Smith, I. Heywood, Benne W. Holwerda, J. Liske, A. R. Lopez-Sanchez, D. Mcconnell, A. Moffett, M. S. Owers, K. A. Pimbblet, W. Raja, N. Seymour, M. A. Voronkov, L. Wang

Faculty and Staff Scholarship

We have observed the G23 field of the Galaxy AnMass Assembly (GAMA) survey using the Australian Square Kilometre Array Pathfinder (ASKAP) in its commissioning phase to validate the performance of the telescope and to characterise the detected galaxy populations. This observation covers ∼48 deg2 with synthesised beam of 32.7 arcsec by 17.8 arcsec at 936MHz, and ∼39 deg2 with synthesised beam of 15.8 arcsec by 12.0 arcsec at 1320MHz. At both frequencies, the root-mean-square (r.m.s.) noise is ∼0.1 mJy/beam. We combine these radio observations with the GAMA galaxy data, which includes spectroscopy of galaxies that are i-band selected with a …

Classification Of Stars From Redshifted Stellar Spectra Utilizing Machine Learning, Michael J. Brice

All Master's Theses

The classification of stellar spectra is a fundamental task in stellar astrophysics. There have been many explorations into the automated classification of stellar spectra but few that involve the Sloan Digital Sky Survey (SDSS). Stellar spectra from the SDSS are applied to standard classification methods such as K-Nearest Neighbors, Random Forest, and Support Vector Machine to automatically classify the spectra. Stellar spectra are high dimensional data and the dimensionality is reduced using standard Feature Selection methods such as Chi-Squared and Fisher score and with domain-specific astronomical knowledge because classifiers work in low dimensional space. These methods are utilized to classify …

Sky Surveys Scheduling Using Reinforcement Learning, Andres Felipe Alba Hernandez

Graduate Research Theses & Dissertations

Modern cosmic sky surveys (e.g., CMB S4, DES, LSST) collect a complex diversity of astronomical objects. Each of class of objects presents different requirements for observation time and sensitivity. For determining the best sequence of exposures for mapping the sky systematically, conventional scheduling methods do not optimize the use of survey time and resources. Dynamic sky survey scheduling is an NP-hard problem that has been therefore treated primarily with heuristic methods. We present an alternative scheduling method based on reinforcement learning (RL) that aims to optimize the use of telescope resources for scheduling sky surveys.

We present an exploration of …