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Dissertations / Theses on the topic 'Physics and Astronomy (miscellaneous)'

Author: Grafiati

Published: 9 July 2021

Last updated: 29 July 2025

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1

Hicks, Adam Scott. "A.C.C.E.S.S. alternative conceptions : a comprehensive examination of space science /." Oxford, Ohio : Miami University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1250084491.

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2

Nixon, Gilbert. "Data acquisition and control in particle physics and astronomy." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340538.

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3

Davis, Adam N. "Astrophysical Constraints on Fundamental Parameters in Physics and Astronomy." Case Western Reserve University School of Graduate Studies / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=case1098973318.

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Davis, Adam N. "Astrophysical constraints on fundamental paramenters in physics and astronomy." online version, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1098973318.

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5

Ignace, Richard. "Astro4U: An Introduction to the Science of the Cosmos." Digital Commons @ East Tennessee State University, 2017. https://www.amzn.com/1516506782/.

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The book Astro4U: An Introduction to the Science of the Cosmos excites students about the grandeur of astronomy and how the universe functions. Filled with vibrant figures and informative tables that support the written text, the book has a fresh, casual, student-friendly tone that dramatically increases interest in the material while also making it more accessible.The book provides a college-level description of science, with astronomy serving as the vehicle of delivery for displaying the scientific model. The content follows a traditional progression, beginning with a study of the sky, follo

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6

Nayakshin, Sergei Victor 1969. "Physics of accretion disks with magnetic flares." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288916.

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Rapid progress in multi-wavelength observations of Seyfert Galaxies in recent years is providing evidence that X-ray emission in these objects may be produced by magnetic flares occurring above a cold accretion disk. Here we attempt to develop a physically consistent model of accretion disks producing radiation via magnetic flares as well as the optically thick intrinsic disk emission, and apply this model to observations of Active Galactic Nuclei (AGN) and Galactic Black Hole Candidates (GBHCs). The following issues are considered: (1) the pressure equilibrium in the flare region, (2) the ref

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7

Booker, Joseph J. "Characterizing the Role of Feedback and Protostellar Properties in the Orion Molecular Clouds." University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1501868933007357.

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8

Bennett, Bryce Hemsley. "The Keplerian Revolution, astronomy, physics, and the argument for heliocentrism." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0003/NQ42500.pdf.

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9

D'addabbo, Antonio. "Applications of Kinetic Inductance Detectors to Astronomy and Particle Physics." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY064/document.

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Les Détecteurs a Inductance Cinétique (KID) ont récemment attiré l'attention de la communauté des détecteurs fonctionnants à très basse température (~100 mK). Haute sensibilité, une fabrication simple, une lecture à faible constante de temps et un multiplexage fréquentielle intrinsèque, ouvrent de nouvelles possibilités pour les expériences necessitant des matrices de détecteurs ultra-sensibles avec un grand nombre de pixels. En astronomie millimétrique, l'instrument New IRAM KID Array (NIKA) est aujourd'hui la meilleure démonstration des performances optiques des ces détecteurs. Cette dernièr

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10

Gonzales, Alexandria. "The Great Galactic Oversight - Characterizing the Most Numerous Stars in the Galaxy." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/341.

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Stars with masses roughly less than half a solar mass, M stars, constitute 75% of all stars in the Galaxy. However, due to their enigmatic nature, it remains difficult to measure these stars' physical properties. This project performs such characterization through the investigation of eclipsing binary star systems. By utilizing precise photometric data from NASA's Kepler Mission, we present this study on all M star eclipsing binaries in the Kepler dataset. We modeled our selected targets' light curves using existing code and vetted our sample for prime candidates for radial velocity follow up.

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11

Sullivan, Peter William. "Simulations and technology development for time-domain astronomy : TESS and InGaAs detectors." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99278.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Physics, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 151-155).<br>Optical time-domain astronomy is in the midst of significant developments due to new instruments, data processing techniques, and space missions. The Kepler mission has identified thousands of exoplanet systems with the transit technique, allowing the first statistical analyses of the exoplanet population. The upcoming Transiting Exoplanet Survey Satellite (TESS) mission will complement Kepler by identifying the br

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12

Ferdman, Robert Daniel. "Binary pulsars: evolution and fundamental physics." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/370.

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In the standard theory of pulsar spin-up, a neutron star (NS) in a binary system accretes matter from its companion star; this serves to transfer angular momentum to the NS, increasing the spin frequency of the pulsar. Measurement of the orbital parameters and system geometry, and in particular the final system masses, thus provide important constraints for theories regarding binary evolution. We present results from an investigation of three binary pulsar systems. PSR J1802-2124 is in an intermediate-mass pulsar binary system with a massive white dwarf companion in a compact orbit with a peri

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13

Bohlouli, Zanjani Parisa. "HIGH RESOLUTION MICROWAVE SPECTROSCOPY OF ULTRA COLD RYDBERG ATOMS AS A PROBE OF ELECTRIC AND MAGNETIC FIELDS." Thesis, University of Waterloo, 2003. http://hdl.handle.net/10012/1260.

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In highly excited Rydberg atoms, the excited electron is in a large, loosely bound orbit. Hence, in contrast with the ground states, the Rydberg states are very sensitive to external electric field and can be ionized in rather weak fields. The low ionization threshold of Rydberg states results in effective state-specific detection by the selective field ionization technique. In this thesis, high-resolution spectroscopy of Rydberg states of Rubidium using millimeter wave transitions and selective field ionization has been used as a probe of external electric and magnetic fields. La

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14

Roberts, John Anthony. "An investigation of Nova Persei (1901) and its environment." Thesis, University of Central Lancashire, 1989. http://clok.uclan.ac.uk/20151/.

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The nature of the ambient medium about the classical nova GK Persei (Nova Persei 1901) has been investigated using IRAS far-infrared and optical observations, coupled with detailed modelling of the optical light echoes. Measurements of the time-dependent expansion of the nova ejecta show that significant deceleration is occurring in the SW quadrant, otherwise the expansion appears fairly uniform at a velocity of around 1200 km s. Interaction with the surrounding medium is the likely cause of this deceleration. Analysis of IRAS 12-100pm raw data reveals that GK Per is centrally positioned on a

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15

Stevens, Jason Anthony. "Multifrequency observations of blazars." Thesis, University of Central Lancashire, 1995. http://clok.uclan.ac.uk/20140/.

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Blazars are a class of active galactic nuclei (AGN). Active galaxies are those that host compact sources of non-thermal radiation in their nuclear regions and are usually classified as being radio-loud or radio-quiet. The nature of the central source is ullcertain, but arguments based on energy budget suggest that accretion onto a supermassive black hole is the most probable scenario (Rees 1984). At present, there is no satisfactory theory that can explain the difference between radio-loud and radio-quiet AGN. The emission from radio-quiet AGN is regarded as being thermal in origin. Thermal re

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16

Hall, II Zack B. "General Relativistic Non-Radial Oscillations in Compact Stars." Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10604673.

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<p> Currently, we lack a means of identifying the type of matter at the core of compact stars, but in the future, we may be able to use gravitational wave signals produced by fluid oscillations inside compact stars to discover new phases of dense matter. To this end, we study the fluid perturbations inside compact stars such as Neutron Stars (NS) and Strange Quark Stars (SQS), focusing on modes that couple to gravitational waves (GWs). Using a modern equation of state for quark matter that incorporates interactions at moderately high densities, we implement an efficient computational scheme to

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17

Leaver, Marc Steven. "A structural study of lyotropic liquid crystal phases formed by aqueous solutions of fluorinated surfactants." Thesis, University of Central Lancashire, 1992. http://clok.uclan.ac.uk/20298/.

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The binary lyotropic liquid crystalline system Caesium Perfluorooctanoate (CsPFO) / heavy water (2H20) has previously been reported to exhibit three mesogenic phases. These were, as a function of decreasing temperature at fixed concentration and pressure isotropic, nematic and lamellar. The mesogenic unit in all three mesophases was reported to be a discrete discoidal micelle. In this project the binary system, as well as the ternary systems upon the addition of an electrolyte and a cosurfactant, have been studied using optical microscopy, small angle neutron and X-ray scattering (SANS and SAX

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Duncan, Nicole. "Gamma-Ray Observations of Solar Flares with RHESSI Imaging Spectroscopy and the GRIPS instrument." Thesis, University of California, Berkeley, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10620536.

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<p> Solar flares can release ~1e33 ergs of power, accelerate particles to relativistic speeds, heat plasma to ~15 million K and catastrophically reorganize 1e5 km long field structures in 100s–1000s of seconds. Magnetic reconnection of large-scale field structures in the corona are thought to power flares, but the precise mechanisms that convert the stored magnetic energy into particle kinetic energy are poorly understood. </p><p> Flare spectra in the 20 keV–10 MeV energy range are rich with information that provide a window into the underlying physics of flare particle accelera

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19

Kerr, Thomas Hugh. "Infrared spectroscopy of interstellar grains." Thesis, University of Central Lancashire, 1994. http://clok.uclan.ac.uk/21040/.

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Spectra are presented of interstellar 1120 and CO ices in three molecular douds. The high signal—to—noise in many of these enabled high quality comparisons to be made with laboratory data, constraining mantle constituents and thermal history. CGS 4 spectra of H 2 0 ices in the p Oph cloud were best fitted with two—component laboratory spectra of non—processed and thermally processed 1120 ices. Variations in the depth of the 3.4 jim excess absorption between lines of sight implied that heating weakens this feature. No features due to C11 30H ices were detected, but a feature at 3.47 pm was obse

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Verma, Poonam Santosh. "Large Scale Computer Investigations of Non-Equilibrium Surface Growth for Surfaces From Parallel Discrete Event Simulations." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-04192004-140532/.

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The asymptotic scaling properties of conservative algorithms for parallel discrete-event simulations (e.g.: for spatially distributed parallel simulations of dynamic Monte Carlo for spin systems) of one-dimensional systems with system size $L$ is studied. The particular case studied here is the case of one or two elements assigned to each processor element. The previously studied case of one element per processor is reviewed, and the two elements per processor case is presented. The key concept is a simulated time horizon which is an evolving non equilibrium surface, specific for the particula

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21

Carter, Frances D. "A THEORETICAL AND EXPERIMENTAL INVESTIGATION OF POWER TRANSMISSION IN A LARGE DIAMETER OPTICAL FIBER." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07062004-151929/.

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The effect of varying the angle of incidence of a Gaussian beam from a He-Ne laser incident upon a large radius optical fiber is theoretically and experimentally investigated. The modes in a weakly-guiding, step index fiber were determined by using an analytical approximation technique to calculate the corresponding eigenvalues. An expression was developed for the fractional power per mode as a function of the angle of incidence for such a fiber. This expression was used to calculate the fractional power per mode for the lowest order 171 modes. This allowed the calculation of the fractional po

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22

Tiwari, Vidhu Shekhar. "DEVELOPMENT OF FIBER OPTIC SENSOR BASED ON LASER RAMAN SPECTROSCOPY." MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07082008-143038/.

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Laser Raman Spectroscopy (LRS) has received worldwide acknowledgement as a powerful molecular finger print technique. The Raman spectrum of sample contains useful information such as molecular identity, composition, constituents concentration ratio etc. These information are manifested in the Raman spectrum in band heights, peak wavelength, band areas etc. The basis of quantitative analysis in Raman spectroscopy lies in the measurement of Raman band intensity, which is linearly dependent upon the sample concentration. On the other hand, Raman spectroscopy can also yield the qualitative informa

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23

Logue, Daniel B. "A Single Continuous Function as a Model for Fast Rise Exponential Decay Gamma-Ray Bursts." MSSTATE, 2006. http://sun.library.msstate.edu/ETD-db/theses/available/etd-09172006-103058/.

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A quantitative analysis was performed on a sample of Fast-Rise Exponential-Decay gamma-ray bursts using a continuous fitting function. The data were obtained from the Large Area detector catalogue of the Burst and Transient Source Experiment, which flew from 1991-2000 onboard the Compton Gamma-Ray Observatory. The purpose here is to tabulate from the fits quantities associated with gamma-ray bursts, emphasising peak intensity, duration, and characteristic rates of rising and falling. V/Vmax and duration analyses show that the sample of bursts is representative of the larger population of gamma

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24

KIM, CHAN KYU. "DEVELOPMENT OF BIO-PHOTONIC SENSOR BASED ON LASER-INDUCED FLUORESCENCE." MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11052007-092200/.

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Laser-induced fluorescence (LIF) has been shown to be potentially useful for identifying microorganisms in real time. It is a selective and sensitive technique because the excitation is performed at one wavelength while the emission is monitored at longer wavelengths so that background from the excitation source can be eliminated. This specialized optical property of LIF can be applied to development of an optical sensor capable of quickly, non-invasively, and quantitatively probing complex biochemical transformations in microorganisms. Various bio-photonic optical fiber sensors based on laser

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Zhang, Xingjun. "Critical Properties of Small World Ising Models." MSSTATE, 2005. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11102005-220554/.

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In this dissertation, the critical scaling behavior of magnetic Ising models with long range interactions is studied. These long range interactions, when imposed in addition to interactions on a regular lattice, lead to small-world graphs. By using large-scale Monte Carlo simulations, together with finite-size scaling, the critical behavior of a number of different models is obtained. The Ising models studied in this dissertation include the z-model introduced by Scalettar, standard small-world bonds superimposed on a square lattice, and physical small-world bonds superimposed on a square latt

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26

Mazzotti, Fabio Jerome. "INVESTIGATION OF INDUCTIVELY COUPLED PLASMA AS AN ATOMIZATION SOURCE FOR ANALYTICAL AND FUNDAMENTAL MEASUREMENTS USING CAVITY RINGDOWN SPECTROSCOPY." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11112004-161954/.

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Analytical as well as fundamental measurements were performed with an inductively coupled plasma (ICP) using the novel technique of cavity ringdown spectroscopy. A newly designed ICP torch was presented. Limits of detection were measured for elemental mercury, both in an ICP as well as in a cold mercury chemical generator. The efficiency of the technique was compared with laser-induced fluorescence (LIF) in the ICP. Isotopically resolved spectra of uranium were collected with this technique and results were compared to previous studies using LIF. Gas temperature and electron density estimation

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27

Ahmed, Maqbool. "First indications of causal set cosmology." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2006. http://proquest.umi.com/login?COPT=REJTPTU0NWQmSU5UPTAmVkVSPTI=&clientId=3739.

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28

Tojeiro, Rita. "Analysing observables in structure formation theories." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3190.

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This thesis presents an exploration of various aspects relating to the formation and evolution of structure in the Universe. It focuses on two main observables which provide information on two distinct epochs of the Universe: Part I analyses the Cosmic Microwave Background (CMB) which is used to test early Universe theories and validate current methods for cosmological parameters estimation; Part II analyses the distribution, history and content of local galaxies with a view to learn about type Ia supernovae progenitors, assembly of stellar mass in galaxies and galaxy evolution. In Part I, a s

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Cigan, Phillip Johnathan. "Neutral interstellar medium phases and star formation tracers in dwarf galaxies." Thesis, New Mexico Institute of Mining and Technology, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3718424.

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<p> Dwarf galaxies present interesting observational challenges for the studies of various galaxy properties: despite their abundance and proximity to the Milky Way, they typically have very low surface brightnesses and small physical sizes. Until now, only the extreme variety of dwarfs — those undergoing strong bouts of star formation — have been observed in the FIR, due to observational difficulties. However, this population does not represent the majority of dwarfs, which have only moderate star formation rates and extremely low metallicity (the fraction of heavy elements to hyd

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Hollowood, Devon. "Cosmological Studies through Large-Scale Distributed Analysis of Chandra Observations." Thesis, University of California, Santa Cruz, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10973254.

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<p> The formation history of galaxy clusters is a powerful probe of cosmology. In particular, one may place strong constraints on the dark energy equation of state by examining the evolution across redshift of the number density of galaxy clusters as a function of mass. In this thesis, I describe my contributions to cluster cosmology, in particular to the development of the richness optical observable mass proxy. </p><p> I introduce <i>redMaPPer</i>, an optical cluster finder which represents an important upstream input for my thesis work. I next introduce the <b>M</b>ass <b>A</b>nalysis <b>

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31

Fleuren, Simone. "The submillimetre and near-infrared properties of Herschel-ATLAS sources." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8462.

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In this thesis I investigate a sample of galaxies that are detected with the Herschel Space Telescope in the sub-millimetre wavelength range and that also have near-infrared detections with the VISTA telescope in Chile as part of the VIKING survey. The first necessity is to find the near-infrared galaxies that are most likely to be the counterparts to the Herschel galaxies. I accomplish this by using a likelihood ratio method which I modify to allow for an appropriate estimate of the probability of finding a genuine near-infrared counterpart above the magnitude limit to a SPIRE source. This pr

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Macey, Tom. "An algorithm to measure parton fragmentation at large hadron colliders." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8657.

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The Standard Model of particle physics is discussed with emphasis on light quark QCD, and existing data on light quark fragmentation from e+e annihilation and deep inelastic scattering experiments. A method is developed to measure the directionally correlated pionic scaled momentum distribution, or partonic fragmentation function, in large hadron collider conditions. Jet algorithms are used to provide partonic momentum estimates, which in turn scale the hadronic momenta. The associated resolution is unfolded. Hadronic profiles about the parton are examined at Monte Carlo "truth" level. There i

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Little, William Robert. "Structure of, and light emission in, matrix-free Germanium quantum dots." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8954.

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The connection between light emission and structure of Germanium nanoparticles (3-10 nm) prepared by top-down (etching) and bottom-up (sol-gel and colloidal synthesis) has been investigated using Raman spectroscopy, TEM, x-ray absorption spectroscopy (XAS), x-ray di raction (XRD), and photoluminescence (PL). It was found that TEM, Raman spectroscopy, PL, and XRD techniques all result in di ering values for the nanoparticle size which don't all agree in the limit of experimental error. Several structural models have been proposed and tested by high pressure Raman measurements. It was found that

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Bolmatov, Dmitry. "Thermodynamic, dynamic and structural properties of liquid and supercritical matter." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8371.

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Among three basic states of matter (solid, liquid, gas), liquids are least understood from the theoretical point of view. The perceived diffculty is that interactions in a liquid are both strong and system-specific, implying that the energy strongly depends on the liquid type and that, therefore, liquid energy can not be calculated in general form. In this thesis, a phonon theory of liquids is developed where this problem is avoided. Central to the thesis is a development an alternative to calculating liquid energy and heat capacity. The proposed phonon theory of liquids covers both classical

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35

Khademi, S. "The effects of excited states and energetic traps on charge transport in disordered organic small molecule semiconductors." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8499.

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Charge transport is the one the most fundamental concepts in organic semiconductors. The key quantity that characterises this transport behaviour is carrier mobility. The ability to transport carriers in a fast and unimpeded nature in organic devices such as Organic Photovoltaics (OPV) or Organic Light Emitting Diodes (OLED) is a key parameter for building more efficient devices. Significant steps have so far been taken to understand and model this phenomenon, however there are still many questions that need to be answered. One such fundamental question is the role of excited states on the cha

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Elliston, Joseph. "Observable predictions of generalised inflationary scenarios." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8457.

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Inflation is an early period of accelerated cosmic expansion, thought to be sourced by high energy physics. A key task today is to use the influx of increasingly precise observational data to constrain the plethora of inflationary models suggested by fundamental theories of interactions. This requires a robust theoretical framework for quantifying the predictions of such models; helping to develop such a framework is the aim of this thesis. We begin by providing the first complete quantization of subhorizon perturbations for the well-motivated class of multi-field inflationary models that poss

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Black, William. "Gravitational effects from amplitudes for string-brane interactions." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8368.

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In this thesis we examine both high and low energy gravitational phenomena using amplitudes derived from a quantum description of interactions between strings and branes. We demonstrate that the coupling of branes to the massless states of the closed string exactly match the couplings of these branes at low energy to the supergravity fields associated with these states. We examine the scattering of massive closed strings from a brane at high energy and large impact parameters and it is concluded that this process can be well approximated by an eikonal description.

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Deaton, Michael Brett. "Neutrinos in mergers of neutron stars with black holes." Thesis, Washington State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3732682.

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<p> Mergers of a neutron star and a black hole are interesting because of the dual complexity of the black hole's strong gravity and the neutron star's nuclear-density fluid. Mergers can yield short-lived nuclear accretion disks, emitting copious neutrinos. This radiation may change the thermodynamic state of the disk itself, may drive an ultrarelativistic jet of electrons and positrons, may oscillate in its flavor content, may irradiate surrounding matter, playing a role in nucleosynthesis, and may be detected directly. </p><p> In this thesis I present a model of such a merger, its remnant

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Asbell, Jessica Lee. "Non-radial fluid pulsation modes of compact stars." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10150591.

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<p> The observation of gravitational waves from compact stars (neutron and quark stars) is a promising method of determining their internal composition. This research presents the details and results for calculations of some of the principal modes of compact star oscillations, by which they radiate gravitational waves. These are: the <i>f</i>-modes, <i>p</i>-modes, and <i>g</i>-modes. We find that for the same stellar mass, the <i> f</i>-modes for quark stars are higher in frequency than for neutron stars. The <i>p</i>-mode frequency of quark stars decrease with stellar mass, displaying an

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Davidson, James W. Jr. "A New Era of Observational Capability at Ritter Observatory: Spectropolarimetry from Exoplanets to Circumstellar Disks and Beyond." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365171803.

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Egeland, Ricky Alan. "Long-Term Variability of the Sun in the Context of Solar-Analog Stars." Thesis, Montana State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10267829.

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<p> The Sun is the best observed object in astrophysics, but despite this distinction the nature of its well-ordered generation of magnetic field in 11-year activity cycles remains a mystery. In this work, we place the solar cycle in a broader context by examining the long-term variability of solar analog stars within 5% of the solar effective temperature, but varied in rotation rate and metallicity. Emission in the Fraunhofer H & K line cores from singly-ionized calcium in the lower chromosphere is due to magnetic heating, and is a proven proxy for magnetic flux on the Sun. We use Ca H &a

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Ayala, Solares Hugo Alberto. "Search for High-Energy Gamma Rays in the Northern Fermi Bubble Region with the HAWC Observatory." Thesis, Michigan Technological University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10261010.

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<p> Gamma-ray astronomy is the study of very energetic photons, from <i> E</i> = <i>m<sub>e</sub>c</i><sup>2</sup> ≈0.5×10<sup> 6</sup> eV to > ≥10<sup>20</sup>eV. Due to the large span of the energy range, the field focuses on non-thermal processes that include the acceleration and propagation of relativistic particles, which can be found in extreme environments such as pulsars, supernova remnants, molecular clouds, black holes, etc.</p><p> The High Altitude Water Cherenkov (HAWC) observatory is an instrument designed for the study of gamma rays in the energy range of &sim;100 G

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Jiang, Fangzhou. "Characterizing the Substructure of Dark Matter Halos." Thesis, Yale University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10584949.

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<p>Hierarchical structure formation in the standard Λ+cold dark matter (CDM) model produces gravitationally bound clumpy halos with abundant substructure. These subhalos are the remnants of dark matter halos that have been accreted by their host halo over cosmic time, and have survived tidal destruction. Understanding halo substructure is extremely important, as subhalos are believed to host satellite galaxies, boost the dark matter annihilation signal, cause tidal heating of fragile structures such as stellar streams and disks, and are potentially responsible for interesting phenomena

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44

Hahn, ChangHoon. "Galaxies and Their Host Dark Matter Structures." Thesis, New York University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10261676.

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<p> Through their connection with dark matter structures, galaxies act as tracers of the underlying matter distribution in the Universe. Their observed spatial distribution allows us to precisely measure large scale structure and effectively test cosmological models that explain the content, geometry, and history of the Universe. Current observations from galaxy surveys such as the Baryon Oscillation Spectroscopic Survey have already probed vast cosmic volumes with millions of galaxies and ushered in an era of precision cosmology. The next surveys will probe over an order of magnitude more. Wi

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Oates, Anthony Patrick. "A technique for astronomical spectroscopy with a multi-aperture telescope." Thesis, University of Central Lancashire, 1985. http://clok.uclan.ac.uk/19078/.

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A technique for acquiring spectral line data using a multi-aperture telescope is described. The multi-aperture principle and the criteria which led to the selection of a dispersive spectrometer are discussed. The problem of linking telescope and spectrometer has been solved by incorporating low loss optical fibres and this is also discussed. The problems of automatic data collection, its manipulation, display and storage presented a major research effort which were largely overcome by the use of cheap, digital micro-computers. To achieve rapid and flexible data handling the i.E.E.E. bus was us

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Koers, Hylke Bernd Jan. "The Astrophysical Herald neutrinos as probes for particle physics and astronomy /." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2007. http://dare.uva.nl/document/51208.

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Birdie, Christina, B. Sreeharsha, T. Pallavi, and Mahantesh Kannur. "Archiving of Electronic Journals in Physics and Astronomy: Role of Consortia." Information and Library Network Centre, An IUC of University Grants Commission, 2003. http://hdl.handle.net/10150/106409.

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Electronic journals unfold their most valuable features when they are inter-linked with other documents, archives and databases. These electronic journals need an archiving system that is based on a global concept. Archiving ensures "continued access indefinitely into the future of records stored in digital electronic form". Archiving system has to be flexible to adopt the new technological generation. The rapid pace at which technology becomes obsolete makes archiving an extremely expensive undertaking. The librarians are more concerned about the archiving of the electronic journals themselve

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Pattie, Robert. "UCNA/UCNA+." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/5594.

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The neutron provides a simple yet dynamic nuclear system to study the Standard Model of Particle Physics. The process of transforming a neutron into a proton, an electron, and an anti-neutrino contains a wealth of information in the decay rate and the kinematics of the emitted particles. Precision measurements of angular correlations in neutron β-decay can lend insight to the structure of the weak interaction and probe for physics beyond the Standard Model. The UCNA experiment at the Los Alamos Neutron Science Center is the only experiment to use ultracold neutrons to perform such a measuremen

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Bennet, Euan David. "Cosmic magnetism : the plasma physics of the recombining universe." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3695/.

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This thesis presents an analytical and computational approach to modelling partially ionised, spatially-inhomogeneous and recombining plasmas. The specific context for this study is astrophysical plasmas, the early Universe in particular. Two models are investigated in detail: a magnetohydrodynamic (MHD) plasma model to simulate partially ionised plasmas; and a fully electromagnetic/kinetic model, used to study recombining plasmas. The first section further develops an existing computational model of a partially ionised plasma as a mixture of two cospatial fluids: an MHD plasma and a neutral g

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De, Felice Antonio. "The accelerating universe and other cosmological aspects of modified gravity models." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2005. http://wwwlib.umi.com/cr/syr/main.

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