subject:( Stellar Magnetism )

Queens University

1. Shultz, Matthew. The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars .

Degree: Physics, Engineering Physics and Astronomy, 2016, Queens University

URL: http://hdl.handle.net/1974/14691

► How do the magnetic fields of massive stars evolve over time? Are their gyrochronological ages consistent with ages inferred from evolutionary tracks? Why do most… (more)

▼ How do the magnetic fields of massive stars evolve over time? Are their gyrochronological ages consistent with ages inferred from evolutionary tracks? Why do most stars predicted to host Centrifugal Magnetospheres (CMs) display no Hα emission? Does plasma escape from CMs via centrifugal breakout events, or by a steady-state leakage mechanism? This thesis investigates these questions via a population study with a sample of 51 magnetic early B-type stars. The longitudinal magnetic field \bz~was measured from Least Squares Deconvolution profiles extracted from high-resolution spectropolarimetric data. New rotational periods P_rot were determined for 15 stars from \bz, leaving only 3 stars for which P_rot is unknown. Projected rotational velocities \vsini~were measured from multiple spectral lines. Effective temperatures and surface gravities were measured via ionization balances and line profile fitting of H Balmer lines. Fundamental physical parameters, \bz, \vsini, and P_rot were then used to determine radii, masses, ages, dipole oblique rotator model, stellar wind, magnetospheric, and spindown parameters using a Monte Carlo approach that self-consistently calculates all parameters while accounting for all available constraints on stellar properties. Dipole magnetic field strengths B_d follow a log-normal distribution similar to that of Ap stars, and decline over time in a fashion consistent with the expected conservation of fossil magnetic flux. P_rot increases with fractional main sequence age, mass, and B_d, as expected from magnetospheric braking. However, comparison of evolutionary track ages to maximum spindown ages t_S,max shows that initial rotation fractions may be far below critical for stars with M_*>10 M_\odot. Computing t_S,max with different mass-loss prescriptions indicates that the mass-loss rates of B-type stars are likely much lower than expected from extrapolation from O-type stars. Stars with Hα in emission and absorption occupy distinct regions in the updated rotation-magnetic confinement diagram: Hα-bright stars are found to be younger, more rapidly rotating, and more strongly magnetized than the general population. Emission strength is sensitive both to the volume of the CM and to the mass-loss rate, favouring leakage over centrifugal breakout.

Subjects/Keywords: Stellar Winds ; Binary Stars ; Magnetospheres ; Massive Stars ; Magnetic Braking ; Stellar Magnetism ; Spectropolarimetry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Shultz, M. (2016). The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars . (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/14691

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Shultz, Matthew. “The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars .” 2016. Thesis, Queens University. Accessed March 07, 2021. http://hdl.handle.net/1974/14691.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Shultz, Matthew. “The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars .” 2016. Web. 07 Mar 2021.

Vancouver:

Shultz M. The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars . [Internet] [Thesis]. Queens University; 2016. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1974/14691.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Shultz M. The Rotational Evolution and Magnetospheric Emission of the Magnetic Early B-type Stars . [Thesis]. Queens University; 2016. Available from: http://hdl.handle.net/1974/14691

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Colorado

2. Augustson, Kyle C. Convection and Dynamo Action in Massive Stars.

Degree: PhD, Astrophysical & Planetary Sciences, 2013, University of Colorado

URL: https://scholar.colorado.edu/astr_gradetds/26

► Contact between numerical simulations and observations of stellar magnetism is sought, with an emphasis on those stars that are the most readily observed and… (more)

▼ Contact between numerical simulations and observations of stellar magnetism is sought, with an emphasis on those stars that are the most readily observed and those that may have magnetic activity cycles: the Sun, F-type, and B-type stars. Two approaches are taken in studying stellar dynamos and dynamics, utilizing three-dimensional MHD simulations run on massively parallel supercomputers with the full spherical geometry and employing a new compressible code in the spherical wedge geometry. A 3D MHD simulation of the solar dynamo that utilizes the Anelastic Spherical Harmonic (ASH) code is presented. This simulation self-consistently exhibits four prominent aspects of solar magnetism: activity cycles, polarity cycles, the equatorward field migration, and grand minima. The ASH framework and this simulation’s ability to capture many aspects of the solar dynamo represent a first step toward a more complete model of the Sun’s global-scale magnetic activity and its cycles. The dynamics and dynamos of F-type stars are studied through global-scale ASH simulations, with significant contact made between the observed differential rotation and magnetic cycle periods of these stars and those achieved in the simulations. Separately, ASH simulations of core convection in the massive B-type stars show that generation of superequipartition magnetic fields with peak strengths above 1 MG is possible within their cores, which has implications for the evolution of these stars as well as for the properties of their remnants. The internal waves excited by overshooting convection and rotation in these stars radiative exteriors are assessed for their asteroseismic signatures. The results of 3D compressive MHD simulations of the solar near-surface shear layer with the Compressible Spherical Segment (CSS) code are shown, with such layers arising in the coupled dynamics of ASH and CSS as well as in a more rapidly rotating, thin convective envelope of an F-type star. Advisors/Committee Members: Juri Toomre, Bradley W. Hindman, Mark S. Miesch, Mark P. Rast, Jeffrey B. Weiss.

Subjects/Keywords: Dynamo Theory; Fluid Dynamics; Stellar Convection; Stellar Magnetism; Astrophysics and Astronomy; Physical Processes; Stars, Interstellar Medium and the Galaxy

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Augustson, K. C. (2013). Convection and Dynamo Action in Massive Stars. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/astr_gradetds/26

Chicago Manual of Style (16^th Edition):

Augustson, Kyle C. “Convection and Dynamo Action in Massive Stars.” 2013. Doctoral Dissertation, University of Colorado. Accessed March 07, 2021. https://scholar.colorado.edu/astr_gradetds/26.

MLA Handbook (7^th Edition):

Augustson, Kyle C. “Convection and Dynamo Action in Massive Stars.” 2013. Web. 07 Mar 2021.

Vancouver:

Augustson KC. Convection and Dynamo Action in Massive Stars. [Internet] [Doctoral dissertation]. University of Colorado; 2013. [cited 2021 Mar 07]. Available from: https://scholar.colorado.edu/astr_gradetds/26.

Council of Science Editors:

Augustson KC. Convection and Dynamo Action in Massive Stars. [Doctoral Dissertation]. University of Colorado; 2013. Available from: https://scholar.colorado.edu/astr_gradetds/26

Universidade do Rio Grande do Norte

3. Duarte, Tharcisyo Sa e Sousa. Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria .

Degree: 2012, Universidade do Rio Grande do Norte

URL: http://repositorio.ufrn.br/handle/123456789/18597

► This study proposes an observing program focused on the investigation of the stellar magnetism and dynamo evolution in cool active solar-like stars. More mainly in… (more)

Subjects/Keywords: Magnetismo estelar; Evolução; Estrelas análogas solares; Estrelas gêmeas solares; Espectropolarimetria; Stellar magnetism; Spectropolarimetric

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Duarte, T. S. e. S. (2012). Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria . (Thesis). Universidade do Rio Grande do Norte. Retrieved from http://repositorio.ufrn.br/handle/123456789/18597

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Duarte, Tharcisyo Sa e Sousa. “Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria .” 2012. Thesis, Universidade do Rio Grande do Norte. Accessed March 07, 2021. http://repositorio.ufrn.br/handle/123456789/18597.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Duarte, Tharcisyo Sa e Sousa. “Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria .” 2012. Web. 07 Mar 2021.

Vancouver:

Duarte TSeS. Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria . [Internet] [Thesis]. Universidade do Rio Grande do Norte; 2012. [cited 2021 Mar 07]. Available from: http://repositorio.ufrn.br/handle/123456789/18597.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Duarte TSeS. Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria . [Thesis]. Universidade do Rio Grande do Norte; 2012. Available from: http://repositorio.ufrn.br/handle/123456789/18597

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Universidade do Rio Grande do Norte

4. Duarte, Tharcisyo Sa e Sousa. Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria .

Degree: 2012, Universidade do Rio Grande do Norte

URL: http://repositorio.ufrn.br/handle/123456789/18597

► This study proposes an observing program focused on the investigation of the stellar magnetism and dynamo evolution in cool active solar-like stars. More mainly in… (more)

Subjects/Keywords: Magnetismo estelar; Evolução; Estrelas análogas solares; Estrelas gêmeas solares; Espectropolarimetria; Stellar magnetism; Spectropolarimetric

Record Details Similar Records Cite « Share

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Duarte, T. S. e. S. (2012). Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria . (Masters Thesis). Universidade do Rio Grande do Norte. Retrieved from http://repositorio.ufrn.br/handle/123456789/18597

Chicago Manual of Style (16^th Edition):

Duarte, Tharcisyo Sa e Sousa. “Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria .” 2012. Masters Thesis, Universidade do Rio Grande do Norte. Accessed March 07, 2021. http://repositorio.ufrn.br/handle/123456789/18597.

MLA Handbook (7^th Edition):

Duarte, Tharcisyo Sa e Sousa. “Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria .” 2012. Web. 07 Mar 2021.

Vancouver:

Duarte TSeS. Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria . [Internet] [Masters thesis]. Universidade do Rio Grande do Norte; 2012. [cited 2021 Mar 07]. Available from: http://repositorio.ufrn.br/handle/123456789/18597.

Council of Science Editors:

Duarte TSeS. Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria . [Masters Thesis]. Universidade do Rio Grande do Norte; 2012. Available from: http://repositorio.ufrn.br/handle/123456789/18597

5. Buysschaert, Bram. Sismologie des étoiles chaudes magnétiques : Seismology of magnetic massive stars.

Degree: Docteur es, Astronomie et Astrophysique, 2018, Paris Sciences et Lettres (ComUE); Katholieke universiteit te Leuven (1970-....)

URL: http://www.theses.fr/2018PSLEO004

► Environ 10% des étoiles de type spectral O, B ou A ont un champ magnétique fort, détectable, stable et à grande échelle à leur surface,… (more)

▼ Environ 10% des étoiles de type spectral O, B ou A ont un champ magnétique fort, détectable, stable et à grande échelle à leur surface, qui ressemble le plus souvent à un dipôle. Des modèles théoriques et des simulations numériques prédisent ces champs magnétiques vus en surface pénètrent aussi dans les zones radiatives et influencent la structure interne. Les modèles prédisent que ces champs magnétiques imposent une rotation uniforme dans les zones radiatives et peuvent supprimer la pénétration convective autour du cœur. Cela a des conséquences sur l’évolution de ces étoiles chaudes magnétiques. Pour ce faire, l’astérosismologie est la meilleure méthode car les paramètres des pulsations stellaires sont directement liés aux conditions physiques internes. Plusieurs types de pulsations stellaires sont connus et classés en fonction de leur force de rappel. Parmi eux, les plus à même de sonder les régions proches du cœur des étoiles, sur lequel se concentre notre intérêt dans cette thèse sont les modes de gravité, qui sont gouvernés par la force d’Archimède.Notre premier objectif était d’identifier des étoiles chaudes, pulsantes et magnétiques et de caractériser leurs propriétés magnétiques et sismiques. Des étoiles ont été sélectionnées grâce à des diagnostics observationnels indirects de la présence d’un champ magnétique qou nous confirmons grâce à de la spectropolarimétrie optique à haute résolution obtenue avec ESPaDOnS, Narval et ESPaDOnS. Pour deux étoiles magnétiques connues, HD43317 et o Lup, nous avons caractérisé la géométrie et l’intensité du champ magnétique aves des séries temporelles spectropolarimétriques. Pour toutes les étoiles de notre échantillon, nous avons également obtenu des séries temporelles photométriques très précises grâce aux télescopes spatiaux BRITE, CoRoT ou K2 pour étudier leur variabilité (périodique) cohérente. Seulement HD43317 a révélé des dizaines de fréquences de pulsations stellaires, pointant plutôt vers des modes de gravité.Nous nous sommes ensuite concentrés sur HD43317 dans pour déterminer observationellement la structure interne de cette étoile magnétique chaude. Nous avons fait usage de modélisation sismique: les fréquences des modes de pulsations observées dans les données CoRoT, couvrant 150j, ont été ajustées à celles des modes gravito-inertiels calculés avec le code de pulsations GYRE couplé aux modèles MESA. Nous avons pu associer les fréquences des modes de pulsations à des séries de modes (l,m) = (1,−1) et (2,−1) se chevauchant. La petite zone de pénétration convective dans la zone radiative telle que déduite du modèle MESA optimal s’avère cohérente avec les prédictions théoriques. Néanmoins, les intervalles de confiance sur certains paramètres physiques issus des modèles sont très larges et compatibles avec les valeurs de la littérature pour des étoiles chaudes et pulsantes mais non-magnétiques. Nous en concluons que la série temporelle de 150j de données CoRoT est trop courte pour déterminer d’une manière non-équivoque la structure interne des étoiles magnétiques… Advisors/Committee Members: Neiner, Coralie Laurence (thesis director), Aerts, Conny (thesis director).

Subjects/Keywords: Étoiles chaudes; Étoiles pulsantes; Étoiles magnetiques; Astérosismologie; Magnétisme stellaire; Hot stars; Pulsating stars; Magnetic stars; Asteroseismology; Stellar magnetism; 520

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Buysschaert, B. (2018). Sismologie des étoiles chaudes magnétiques : Seismology of magnetic massive stars. (Doctoral Dissertation). Paris Sciences et Lettres (ComUE); Katholieke universiteit te Leuven (1970-....). Retrieved from http://www.theses.fr/2018PSLEO004

Chicago Manual of Style (16^th Edition):

Buysschaert, Bram. “Sismologie des étoiles chaudes magnétiques : Seismology of magnetic massive stars.” 2018. Doctoral Dissertation, Paris Sciences et Lettres (ComUE); Katholieke universiteit te Leuven (1970-....). Accessed March 07, 2021. http://www.theses.fr/2018PSLEO004.

MLA Handbook (7^th Edition):

Buysschaert, Bram. “Sismologie des étoiles chaudes magnétiques : Seismology of magnetic massive stars.” 2018. Web. 07 Mar 2021.

Vancouver:

Buysschaert B. Sismologie des étoiles chaudes magnétiques : Seismology of magnetic massive stars. [Internet] [Doctoral dissertation]. Paris Sciences et Lettres (ComUE); Katholieke universiteit te Leuven (1970-....); 2018. [cited 2021 Mar 07]. Available from: http://www.theses.fr/2018PSLEO004.

Council of Science Editors:

Buysschaert B. Sismologie des étoiles chaudes magnétiques : Seismology of magnetic massive stars. [Doctoral Dissertation]. Paris Sciences et Lettres (ComUE); Katholieke universiteit te Leuven (1970-....); 2018. Available from: http://www.theses.fr/2018PSLEO004

6. Makhfudz, Imam. Novel Phenomena in Modern Studies of Magnetism.

Degree: 2013, Johns Hopkins University

URL: http://jhir.library.jhu.edu/handle/1774.2/36958

► In this PhD Dissertation, we present investigation of contemporary problems in magnetism. We focus on two important themes that have been active research topics in… (more)

▼ In this PhD Dissertation, we present investigation of contemporary problems in magnetism. We focus on two important themes that have been active research topics in condensed matter community: 1. Topological defects in magnet and their dynamics 2. Exotic states and critical phenomena in frustrated spin systems. In the first topic, we consider the dynamics of topological defect known as Skyrmion in thin film ferromagnet. We first discuss the nontrivial dynamics exhibited by a Skyrmion bubble confined in thin film disk as observed by numerical simulation. We propose a phenomenological theory that can reproduce the peculiar dynamics of the Skyrmion bubble. We show that, unlike previously studied topological defects, a Skyrmion bubble possesses inertia. We derive a theoretical description of the dynamics using standard theory of ferromagnet. We discover the presence of two counter propagating chiral edge modes. Most importantly, we derive the mass (inertia) from the theory and express it in terms of microscopic parameters. In the second topic, a quantum phase transition in U(1) quantum spin liquid phase of 3-d pyrochlore quantum spin ice is investigated. Starting from microscopic spin model, we map the spin to slave-boson, derive continuum theory, and finally arrive at a U(1) gauge theory which takes the form of scalar quantum electrodynamics (QED). The effective free energy for quantum spin liquid (QSL) to antiferromagnetic (AFM) phase transition mimics the one for Bardeen-Cooper-Schrieffer (BCS) superconductors classical transition under magnetic field. We show that, provided Ginzburg criterion is satisfied, the gauge field fluctuations drive the originally continuous QSL to AFM phase transition at mean field level into discontinuous one. We predict the location of quantum critical point which agrees well with gauge mean field theory result. We calculate the size of phase transition and find that it is a weakly first order. Advisors/Committee Members: Tchernyshyov, Oleg (advisor).

Subjects/Keywords: magnetism

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Makhfudz, I. (2013). Novel Phenomena in Modern Studies of Magnetism. (Thesis). Johns Hopkins University. Retrieved from http://jhir.library.jhu.edu/handle/1774.2/36958

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Makhfudz, Imam. “Novel Phenomena in Modern Studies of Magnetism.” 2013. Thesis, Johns Hopkins University. Accessed March 07, 2021. http://jhir.library.jhu.edu/handle/1774.2/36958.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Makhfudz, Imam. “Novel Phenomena in Modern Studies of Magnetism.” 2013. Web. 07 Mar 2021.

Vancouver:

Makhfudz I. Novel Phenomena in Modern Studies of Magnetism. [Internet] [Thesis]. Johns Hopkins University; 2013. [cited 2021 Mar 07]. Available from: http://jhir.library.jhu.edu/handle/1774.2/36958.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Makhfudz I. Novel Phenomena in Modern Studies of Magnetism. [Thesis]. Johns Hopkins University; 2013. Available from: http://jhir.library.jhu.edu/handle/1774.2/36958

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Clemson University

7. Tannous, Jaad Antoun. The Effect of Rotation on Stellar Structure and Evolution.

Degree: MS, Physics and Astronomy, 2020, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/3267

► In this thesis, we investigate the eects of rotation on the evolution of stars in the mass range of 2-15 M assuming solar-like initial… (more)

Subjects/Keywords: Rotation; s-process; Stellar Evolution; Stellar Structure

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tannous, J. A. (2020). The Effect of Rotation on Stellar Structure and Evolution. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/3267

Chicago Manual of Style (16^th Edition):

Tannous, Jaad Antoun. “The Effect of Rotation on Stellar Structure and Evolution.” 2020. Masters Thesis, Clemson University. Accessed March 07, 2021. https://tigerprints.clemson.edu/all_theses/3267.

MLA Handbook (7^th Edition):

Tannous, Jaad Antoun. “The Effect of Rotation on Stellar Structure and Evolution.” 2020. Web. 07 Mar 2021.

Vancouver:

Tannous JA. The Effect of Rotation on Stellar Structure and Evolution. [Internet] [Masters thesis]. Clemson University; 2020. [cited 2021 Mar 07]. Available from: https://tigerprints.clemson.edu/all_theses/3267.

Council of Science Editors:

Tannous JA. The Effect of Rotation on Stellar Structure and Evolution. [Masters Thesis]. Clemson University; 2020. Available from: https://tigerprints.clemson.edu/all_theses/3267

University of Sydney

8. Maestro, Vicente. Interferometric observations of hot stars .

Degree: 2014, University of Sydney

URL: http://hdl.handle.net/2123/11671

► Accurate determination of fundamental stellar properties is crucial in understanding and testing models of stellar structure and evolution. To date, most stars with independent determinations… (more)

Subjects/Keywords: Optical Interferometry; Stellar Astrophysics; Stellar rotation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Maestro, V. (2014). Interferometric observations of hot stars . (Thesis). University of Sydney. Retrieved from http://hdl.handle.net/2123/11671

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Maestro, Vicente. “Interferometric observations of hot stars .” 2014. Thesis, University of Sydney. Accessed March 07, 2021. http://hdl.handle.net/2123/11671.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Maestro, Vicente. “Interferometric observations of hot stars .” 2014. Web. 07 Mar 2021.

Vancouver:

Maestro V. Interferometric observations of hot stars . [Internet] [Thesis]. University of Sydney; 2014. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/2123/11671.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Maestro V. Interferometric observations of hot stars . [Thesis]. University of Sydney; 2014. Available from: http://hdl.handle.net/2123/11671

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Manchester

9. Nasralla, Mazin. Fundamental properties and evolution of exoplanets and their host stars.

Degree: 2020, University of Manchester

URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:324561

► This work had two objectives. The first was to derive a program that could, at the push of a button, generate an extended series of… (more)

Subjects/Keywords: exoplanets; stellar tides

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Nasralla, M. (2020). Fundamental properties and evolution of exoplanets and their host stars. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:324561

Chicago Manual of Style (16^th Edition):

Nasralla, Mazin. “Fundamental properties and evolution of exoplanets and their host stars.” 2020. Doctoral Dissertation, University of Manchester. Accessed March 07, 2021. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:324561.

MLA Handbook (7^th Edition):

Nasralla, Mazin. “Fundamental properties and evolution of exoplanets and their host stars.” 2020. Web. 07 Mar 2021.

Vancouver:

Nasralla M. Fundamental properties and evolution of exoplanets and their host stars. [Internet] [Doctoral dissertation]. University of Manchester; 2020. [cited 2021 Mar 07]. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:324561.

Council of Science Editors:

Nasralla M. Fundamental properties and evolution of exoplanets and their host stars. [Doctoral Dissertation]. University of Manchester; 2020. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:324561

University of Oxford

10. McQuillan, Amy. Stellar variability and rotation in Kepler planetary transit search data.

Degree: PhD, 2013, University of Oxford

URL: http://ora.ox.ac.uk/objects/uuid:802a873d-650f-4f0b-b814-f8397b2798e2 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618438

► The recent space-based exoplanet transit searches, CoRoT and Kepler, have revolutionised the field of stellar variability. In this thesis I exploit the public Kepler data… (more)

▼ The recent space-based exoplanet transit searches, CoRoT and Kepler, have revolutionised the field of stellar variability. In this thesis I exploit the public Kepler data to characterise stellar variability, and study rotation periods. For the study of stellar variability it is a complicated but necessary process to remove instrumental systematics while maintaining intrinsic stellar signal. I was involved in the development of a new correction method for systematics, denoted ARC (Astrophysically Robust Correction). This method relies on the removal of a set of basis functions that are determined to be present in small amounts across many light curves. Using the first month of Kepler data, corrected with the ARC method, I studied the variability properties of main sequence stars as a function of fundamental stellar parameters. I find that the fraction of stars with variability greater than that of the Sun is 60%, and confirm the trend of increasing variability with decreasing effective temperatures. I show tentative evidence that the more active stars have lower proper motions and may be located closer to the galactic plane. I also investigate the frequency content of the variability, showing that there exist significant differences in the nature of variability between spectral types, with a trend towards longer periods at later spectral types. In order to exploit the full potential of the Kepler data for stellar rotation period measurement, I developed a novel method of period detection for use on star spot modulated light curves. Standard approaches to period detection are based on Fourier decomposition or least-squares fitting of sinusoidal models. However, typical stellar light curves are neither sinusoidal nor strictly periodic. Therefore, I developed an algorithm for period detection based on the autocorrelation function (ACF) of the light curve. Because the ACF measures only the degree of self-similarity of the light curve at a given time lag, the period remains detectable even when the amplitude and phase of the photometric modulation evolve significantly. I applied the ACF method for the sample of M-dwarfs observed during the first 10 months of the Kepler mission, and detected rotation periods in 1570, ranging from 0.37-69.7 days. The rotation period distribution is clearly bimodal, with peaks at ~19 and ~33 days, hinting at two distinct waves of star formation. These two peaks form two distinct sequences in period-temperature space, with the period decreasing with increasing temperature. In a natural continuation to this work I applied measured periods for 1000 stars in each of the F, G and K-dwarf sets observed by Kepler, and combined these with the M-dwarf results. The trend of increasing rotation period with increasing mass is clear throughout, as the observations fall along a wide by distinct sequence. Comparison to the rotational isochrones of Barnes (2007) show an overall agreement, although the dataset, which I believe is the largest set of rotation period measurements for main sequence stars, shows…

Subjects/Keywords: 523.8; Astrophysics; stellar physics; stellar rotation; stellar variability; systematics removal

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APA (6^th Edition):

McQuillan, A. (2013). Stellar variability and rotation in Kepler planetary transit search data. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:802a873d-650f-4f0b-b814-f8397b2798e2 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618438

Chicago Manual of Style (16^th Edition):

McQuillan, Amy. “Stellar variability and rotation in Kepler planetary transit search data.” 2013. Doctoral Dissertation, University of Oxford. Accessed March 07, 2021. http://ora.ox.ac.uk/objects/uuid:802a873d-650f-4f0b-b814-f8397b2798e2 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618438.

MLA Handbook (7^th Edition):

McQuillan, Amy. “Stellar variability and rotation in Kepler planetary transit search data.” 2013. Web. 07 Mar 2021.

Vancouver:

McQuillan A. Stellar variability and rotation in Kepler planetary transit search data. [Internet] [Doctoral dissertation]. University of Oxford; 2013. [cited 2021 Mar 07]. Available from: http://ora.ox.ac.uk/objects/uuid:802a873d-650f-4f0b-b814-f8397b2798e2 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618438.

Council of Science Editors:

McQuillan A. Stellar variability and rotation in Kepler planetary transit search data. [Doctoral Dissertation]. University of Oxford; 2013. Available from: http://ora.ox.ac.uk/objects/uuid:802a873d-650f-4f0b-b814-f8397b2798e2 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618438

University of Victoria

11. Jensen, Jaclyn. Fossils of the distant Galaxy: NGC 5466 and its stellar stream.

Degree: Department of Physics and Astronomy, 2020, University of Victoria

URL: http://hdl.handle.net/1828/12440

► The stellar halo of the Milky Way is populated by mostly old and metal-poor stars. As dynamical timescales are of order ~Gyrs at these large… (more)

▼ The stellar halo of the Milky Way is populated by mostly old and metal-poor stars. As dynamical timescales are of order ~Gyrs at these large distances, accreted stellar substructures, such as dwarf galaxies or globular clusters, survive here as coherent entities longer than anywhere else in the Galaxy. These substructures represent our “fossil record” which can be used to reconstruct the Galaxy’s complex past. In this work, we seek to identify the structures found in the far reaches of the stellar halo as a step towards a correct interpretation of this fossil record. The advent of all-sky surveys in the Gaia era has ignited a prosperous period for this field of Galactic archaeology, but exploring the distant Milky Way (>10 kpc) with Gaia is difficult. Parallax measurements are much less accurate beyond the Solar neighborhood, though Gaia’s proper motions remain useful out to large radii. To push Gaia into the distant Galaxy, we combined these astrometric data with u-band photometry from the Canada-France Imaging Survey (CFIS). We exploited CFIS’ excellent photometric quality and depth (which extends 3 magnitudes deeper than that of the Sloan Digital Sky Survey) to use blue horizontal branch stars (BHBs) as a tracer population with well-measured distances. We first examined the distribution of BHBs using the OPTICS (Ordering Points To Identify the Clustering Structure) clustering algorithm to visualize the hierarchical nature of outer halo substructure. We then identified several well-known satellites, including a group of stars in the vicinity of a distant globular cluster (NGC 5466). Analysis of their kinematics suggested a few of these BHBs outside the cluster’s tidal radius were co-moving with NGC 5466, implying they may be tidal debris from this system. Interestingly, a stream had previously been detected extending from this globular cluster. However, its properties had not been studied in the decade since its discovery, and previous dynamical models were unable to reproduce many of the reported features. As one of the (allegedly) longest globular cluster streams on the sky - and given its distance and utility to constrain the Milky Way’s mass at large Galactic radius - we sought to explore this structure further. We subsequently used red giant branch stars (RGBs) identified in CFIS to try to better quantify the characteristics of the putative stream. We were able to filter these data and obtain a sample of stars that are fully consistent with stream membership and which span approximately 31 degrees of sky. Combined with the BHBs, we used these populations to trace the path of the stream, its distance and distance gradient across the stream’s longitude, and additionally estimated a lower limit to the stream’s luminosity. Our measurements suggest that the stream is at least 11% of the luminosity of the cluster. We then compared our observational data to dynamical models, which showed generally good agreement with the observed stream. This success reflects the updated properties of data measured in… Advisors/Committee Members: McConnachie, Alan (supervisor), Ellison, Sara L. (supervisor).

Subjects/Keywords: Milky Way; Stellar Populations; Stellar Halo; Stellar Stream; Galactic Dynamics

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APA (6^th Edition):

Jensen, J. (2020). Fossils of the distant Galaxy: NGC 5466 and its stellar stream. (Masters Thesis). University of Victoria. Retrieved from http://hdl.handle.net/1828/12440

Chicago Manual of Style (16^th Edition):

Jensen, Jaclyn. “Fossils of the distant Galaxy: NGC 5466 and its stellar stream.” 2020. Masters Thesis, University of Victoria. Accessed March 07, 2021. http://hdl.handle.net/1828/12440.

MLA Handbook (7^th Edition):

Jensen, Jaclyn. “Fossils of the distant Galaxy: NGC 5466 and its stellar stream.” 2020. Web. 07 Mar 2021.

Vancouver:

Jensen J. Fossils of the distant Galaxy: NGC 5466 and its stellar stream. [Internet] [Masters thesis]. University of Victoria; 2020. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1828/12440.

Council of Science Editors:

Jensen J. Fossils of the distant Galaxy: NGC 5466 and its stellar stream. [Masters Thesis]. University of Victoria; 2020. Available from: http://hdl.handle.net/1828/12440

University of Florida

12. Fleck, Robert Charles, 1949-. Magnetic braking during star formation.

Degree: 1977, University of Florida

URL: https://ufdc.ufl.edu/UF00097484

Subjects/Keywords: Angular momentum; Braking; Cooling; Cosmic rays; Ionization; Magnetic fields; Magnetism; Magnets; Main sequence stars; Stellar rotation; Astronomy thesis Ph. D; Stars – Evolution; Stars – Rotation; Stars, New

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APA (6^th Edition):

Fleck, Robert Charles, 1. (1977). Magnetic braking during star formation. (Thesis). University of Florida. Retrieved from https://ufdc.ufl.edu/UF00097484

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Fleck, Robert Charles, 1949-. “Magnetic braking during star formation.” 1977. Thesis, University of Florida. Accessed March 07, 2021. https://ufdc.ufl.edu/UF00097484.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Fleck, Robert Charles, 1949-. “Magnetic braking during star formation.” 1977. Web. 07 Mar 2021.

Vancouver:

Fleck, Robert Charles 1. Magnetic braking during star formation. [Internet] [Thesis]. University of Florida; 1977. [cited 2021 Mar 07]. Available from: https://ufdc.ufl.edu/UF00097484.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Fleck, Robert Charles 1. Magnetic braking during star formation. [Thesis]. University of Florida; 1977. Available from: https://ufdc.ufl.edu/UF00097484

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

13. Abel, Christopher. Hybrid 3He and alkali magnetometry techniques for fundamental physics experiments.

Degree: PhD, 2020, University of Sussex

URL: http://sro.sussex.ac.uk/id/eprint/90284/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.801064

► Since the 1950s, experiments searching for the neutron electric dipole moment have increased in sensitivity by six orders of magnitude. Yet, the current experimental sensitivity… (more)

▼ Since the 1950s, experiments searching for the neutron electric dipole moment have increased in sensitivity by six orders of magnitude. Yet, the current experimental sensitivity lies well above that predicted from standard model calculations. Corrections from physics beyond the standard model increase the predicted size of the nEDM, resulting in the nextgeneration of experiments hovering tantalisingly close to the detection sensitivity, to either verify or quash standard model extensions. One such experiment, n2EDM, currently in the commissioning stage at the Paul Scherrer Institute in Switzerland, hopes to measure the nEDM with a sensitivity improvement over its predecessor. This thesis details the design, measurement and analysis of hybrid 3He/alkali magnetometers for both accurate and precise magnetic field readings at low and zero fields, crucial for the development of ever-more sensitive fundamental physics searches. The work exploits the precise nature of alkali (87Rb and 133Cs) magnetometry techniques to measure the simultaneous Larmor precession of polarised 3He, avoiding light shifts commonly associated with optically pumped magnetometers. The first part of this work demonstrates the use of a hybrid 3He/87Rb magnetometer for the minimisation of remnant fields in a magnetically shielded environment, resulting in absolute low-field readings below 5 pT. Furthermore, the hybrid magnetometer was shown to be applicable for the reduction of gradient fields by optimising the effective 3He T2 time. This new technique represents a convenient and consistent way to achieve a near-zero magnetic field environment for precision experiments. Second, a new measurement technique was demonstrated using a hybrid 3He/133Cs magnetometer in a 1 μT field, placing experimental limits on the coupling of axion-like dark matter to nucleons. The measurement excluded axion coupling strength to 2:5 x 10-1 GeV-1 for axion masses between 10-20 to 10-17 eV at the 95% level. With the resulting exclusion region weaker than previous measurements, possible improvements to the apparatus should drive the development of a low-cost long-term axion interaction search.

Subjects/Keywords: QC0750 Magnetism

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APA (6^th Edition):

Abel, C. (2020). Hybrid 3He and alkali magnetometry techniques for fundamental physics experiments. (Doctoral Dissertation). University of Sussex. Retrieved from http://sro.sussex.ac.uk/id/eprint/90284/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.801064

Chicago Manual of Style (16^th Edition):

Abel, Christopher. “Hybrid 3He and alkali magnetometry techniques for fundamental physics experiments.” 2020. Doctoral Dissertation, University of Sussex. Accessed March 07, 2021. http://sro.sussex.ac.uk/id/eprint/90284/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.801064.

MLA Handbook (7^th Edition):

Abel, Christopher. “Hybrid 3He and alkali magnetometry techniques for fundamental physics experiments.” 2020. Web. 07 Mar 2021.

Vancouver:

Abel C. Hybrid 3He and alkali magnetometry techniques for fundamental physics experiments. [Internet] [Doctoral dissertation]. University of Sussex; 2020. [cited 2021 Mar 07]. Available from: http://sro.sussex.ac.uk/id/eprint/90284/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.801064.

Council of Science Editors:

Abel C. Hybrid 3He and alkali magnetometry techniques for fundamental physics experiments. [Doctoral Dissertation]. University of Sussex; 2020. Available from: http://sro.sussex.ac.uk/id/eprint/90284/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.801064

McMaster University

14. Cai, Yipeng. Frustrated magnetism studies in NaCaNi$_2$F$_7$, Er$_3$Ga$_5$O$_{12}$ and ErMgGaO$_4$.

Degree: PhD, 2019, McMaster University

URL: http://hdl.handle.net/11375/24584

►

This dissertation details studies of three different frustrated magnet families: NaCaNi₂F₇, Er₃Ga₅O₁₂, and ErMgGaO₄, using a variety of techniques, including magnetization, specific heat, neutron scattering… (more)

▼

This dissertation details studies of three different frustrated magnet families: NaCaNi₂F₇, Er₃Ga₅O₁₂, and ErMgGaO₄, using a variety of techniques, including magnetization, specific heat, neutron scattering and muon spin rotation/relaxation (μSR). NaCaNi₂F₇ belongs to the fluoride pyrochlores family. In this thesis, we study the effect of the randomness on the A site on the magnetic property of B site. This chemical disorder randomness was caused by the mixture of two different elements from Group 1 and 2 (Na and Ca). DFT calculation and computation simulations indicates a possible non-centred F-μ -F muon stopping site. Zero field (ZF) and longitudinal field (LF) μSR shows that the Ni²⁺ spins undergo spin freezing into a disordered ground state below 4K, with persistent spin dynamics to our lowest temperature 75 mK. We obtained high quality single crystal of Er₃Ga₅O₁₂ by utilizing the optical floating-zone (OFZ) technique. We performed inelastic neutron scattering measurements to determine the crystalline electric field (CEF) Hamiltonian, eigenvalues and eigenvectors, indicating an Ising-like anisotropy ground state which is also consistent with our specific heat experiment with entropy approaching Rln(2). All seven crystalline electric field excitations from the ground state Kramers doublet were identified. In addition, Rietveld refinement of neutron powder diffraction data reveal that Er₃Ga₅O₁₂ orders into the Γ₃ magnetic structure, with ordered magnetic moment μ_ord = 5.24(4)~μ_B, in agreement with μ_Ising = 5.61 μ_B from our deduced CEF Hamiltonian. Our μSR measurements also reveals the presence of fluctuating local fields on the muon timescale, indicating exotic slow spin dynamics in the ground state. The objective of the work on ErMgGaO₄ was to identify a new quantum spin liquid candidate. Single crystals of ErMgGaO₄ were obtained through (OFZ) technique as well, and the structure was refined and confirmed by powder X-ray diffraction and Laue diffraction after a repeated refinement of our synthesis process. Susceptibility measurements reveal no evidence of a magnetic transition down to 0.5 K, in agreement with specific heat measurement which exhibit no anomalies which would have been evidence of an ordering transition. ZF-μSR measurements reveal no sign of coherent long range order or spin freezing down to 25 mK, while LF-μSR measurements shows persistent spin dynamics at 25 mK. Our observations provides evidence for a quantum spin liquid ground state in this compound.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Luke, Graeme, Physics and Astronomy.

Subjects/Keywords: Frustrated magnetism

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APA (6^th Edition):

Cai, Y. (2019). Frustrated magnetism studies in NaCaNi$_2$F$_7$, Er$_3$Ga$_5$O$_{12}$ and ErMgGaO$_4$. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/24584

Chicago Manual of Style (16^th Edition):

Cai, Yipeng. “Frustrated magnetism studies in NaCaNi$_2$F$_7$, Er$_3$Ga$_5$O$_{12}$ and ErMgGaO$_4$.” 2019. Doctoral Dissertation, McMaster University. Accessed March 07, 2021. http://hdl.handle.net/11375/24584.

MLA Handbook (7^th Edition):

Cai, Yipeng. “Frustrated magnetism studies in NaCaNi$_2$F$_7$, Er$_3$Ga$_5$O$_{12}$ and ErMgGaO$_4$.” 2019. Web. 07 Mar 2021.

Vancouver:

Cai Y. Frustrated magnetism studies in NaCaNi$_2$F$_7$, Er$_3$Ga$_5$O$_{12}$ and ErMgGaO$_4$. [Internet] [Doctoral dissertation]. McMaster University; 2019. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/11375/24584.

Council of Science Editors:

Cai Y. Frustrated magnetism studies in NaCaNi$_2$F$_7$, Er$_3$Ga$_5$O$_{12}$ and ErMgGaO$_4$. [Doctoral Dissertation]. McMaster University; 2019. Available from: http://hdl.handle.net/11375/24584

Addis Ababa University

15. ABERA, MEBRAHTU. STUDY OF COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM IN SmAsO1􀀀xFxFe .

Degree: 2012, Addis Ababa University

URL: http://etd.aau.edu.et/dspace/handle/123456789/1293

► Superconductivity and magnetism were previously thought as incompatible until the discovery of some rare earth ternary compounds that show the coexistence of superconductivity and magnetism.… (more)

Subjects/Keywords: Superconductivity; magnetism

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APA (6^th Edition):

ABERA, M. (2012). STUDY OF COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM IN SmAsO1􀀀xFxFe . (Thesis). Addis Ababa University. Retrieved from http://etd.aau.edu.et/dspace/handle/123456789/1293

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

ABERA, MEBRAHTU. “STUDY OF COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM IN SmAsO1􀀀xFxFe .” 2012. Thesis, Addis Ababa University. Accessed March 07, 2021. http://etd.aau.edu.et/dspace/handle/123456789/1293.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

ABERA, MEBRAHTU. “STUDY OF COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM IN SmAsO1􀀀xFxFe .” 2012. Web. 07 Mar 2021.

Vancouver:

ABERA M. STUDY OF COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM IN SmAsO1􀀀xFxFe . [Internet] [Thesis]. Addis Ababa University; 2012. [cited 2021 Mar 07]. Available from: http://etd.aau.edu.et/dspace/handle/123456789/1293.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

ABERA M. STUDY OF COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM IN SmAsO1􀀀xFxFe . [Thesis]. Addis Ababa University; 2012. Available from: http://etd.aau.edu.et/dspace/handle/123456789/1293

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Oregon State University

16. Ong, Justin B. Impurity effect on magnetism of nickel for under bump metallization via magnetron sputtering.

Degree: MS, Chemical Engineering, 2010, Oregon State University

URL: http://hdl.handle.net/1957/16471

► Nickel or nickel alloys are common materials used in under bump metallization (UBM) in flip chip technology. Nickel is used because of its slow reaction… (more)

Subjects/Keywords: magnetism; Metallizing

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APA (6^th Edition):

Ong, J. B. (2010). Impurity effect on magnetism of nickel for under bump metallization via magnetron sputtering. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/16471

Chicago Manual of Style (16^th Edition):

Ong, Justin B. “Impurity effect on magnetism of nickel for under bump metallization via magnetron sputtering.” 2010. Masters Thesis, Oregon State University. Accessed March 07, 2021. http://hdl.handle.net/1957/16471.

MLA Handbook (7^th Edition):

Ong, Justin B. “Impurity effect on magnetism of nickel for under bump metallization via magnetron sputtering.” 2010. Web. 07 Mar 2021.

Vancouver:

Ong JB. Impurity effect on magnetism of nickel for under bump metallization via magnetron sputtering. [Internet] [Masters thesis]. Oregon State University; 2010. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1957/16471.

Council of Science Editors:

Ong JB. Impurity effect on magnetism of nickel for under bump metallization via magnetron sputtering. [Masters Thesis]. Oregon State University; 2010. Available from: http://hdl.handle.net/1957/16471

University of Cambridge

17. Hakimi, Ali Moraad Heydar. Magnetism and spin transport studies on indium tin oxide.

Degree: PhD, 2011, University of Cambridge

URL: http://www.dspace.cam.ac.uk/handle/1810/239351https://www.repository.cam.ac.uk/bitstream/1810/239351/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/3/thesis_compiler.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/4/thesis_compiler.pdf.jpg

► This dissertation reports on a detailed systematic study of the investigation into using Indium Oxide based materials in next generation spin-transport electronic applications. Initial studies… (more)

▼ This dissertation reports on a detailed systematic study of the investigation into using Indium Oxide based materials in next generation spin-transport electronic applications. Initial studies focused on the optimisation of the electrical properties of Indium Oxide (In2O3) and Tin(Sn)-doped Indium Oxide (ITO) thin films grown using DC magnetron sputtering. The manipulation of various deposition parameters allowed the electrical properties to be tuned effectively. With the desire to create multi-functional spintronic devices, a dilute magnetic oxide system is developed where the In2O3 and ITO matrices are doped with low levels of transition metals, in particular, Co. Using a number of characterisation techniques, the origins of the magnetic response in these thin films is explored in great detail. In particular, powerful probes such as x-ray and optical magnetic circular dichroism are utilised. The major finding from these investigations is that the magnetism does not necessarily emanate from the Co dopants alone. In fact, Co dopants give a strictly paramagnetic response, suggesting that the magnetism observed may be a result of polarised electrons in localised donor states in the In2O3 and ITO hosts. Therefore, we believe that the origins of magnetism in these films is related to a hybridisation and charge transfer of electrons from a broad donor/defect-derived impurity band to a band of unoccupied 3d states at the Fermi level. The emergence of a very weak magnetic signal in pure ITO raises further questions as to the true origins of the ferromagnetic behaviour and supports a defect-related mechanism. To explore the suitability of ITO for a future in spintronics further, the performance of some metal ferromagnet/oxide multilayered structures was investigated. The investigations revealed a significant contribution to both the magnetic and magnetotransport properties from a superparamagnetic component giving some insight into the importance of the quality of interfaces between the metal ferromagnet/oxide layers and heterostructures. Using a three-dimensional focused-ion beam etching technique to fabricate submicron spin-valve devices with ITO spacer layers, current-perpendicular-to-plane magnetoresistance measurements were carried out to estimate the spin diffusion length of ITO at room temperature. In conjunction with a simplified Valet-Fert model, a spin asymmetry ratio for Co of 0.55 and spin diffusion length of 6±1 nm in semiconducting ITO at room temperature was estimated. These findings imply that spin information can be conserved and transported through In2O3 and ITO even up to and beyond room temperature.

Subjects/Keywords: Magnetism; Spintronics

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APA (6^th Edition):

Hakimi, A. M. H. (2011). Magnetism and spin transport studies on indium tin oxide. (Doctoral Dissertation). University of Cambridge. Retrieved from http://www.dspace.cam.ac.uk/handle/1810/239351https://www.repository.cam.ac.uk/bitstream/1810/239351/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/3/thesis_compiler.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/4/thesis_compiler.pdf.jpg

Chicago Manual of Style (16^th Edition):

Hakimi, Ali Moraad Heydar. “Magnetism and spin transport studies on indium tin oxide.” 2011. Doctoral Dissertation, University of Cambridge. Accessed March 07, 2021. http://www.dspace.cam.ac.uk/handle/1810/239351https://www.repository.cam.ac.uk/bitstream/1810/239351/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/3/thesis_compiler.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/4/thesis_compiler.pdf.jpg.

MLA Handbook (7^th Edition):

Hakimi, Ali Moraad Heydar. “Magnetism and spin transport studies on indium tin oxide.” 2011. Web. 07 Mar 2021.

Vancouver:

Hakimi AMH. Magnetism and spin transport studies on indium tin oxide. [Internet] [Doctoral dissertation]. University of Cambridge; 2011. [cited 2021 Mar 07]. Available from: http://www.dspace.cam.ac.uk/handle/1810/239351https://www.repository.cam.ac.uk/bitstream/1810/239351/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/3/thesis_compiler.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/4/thesis_compiler.pdf.jpg.

Council of Science Editors:

Hakimi AMH. Magnetism and spin transport studies on indium tin oxide. [Doctoral Dissertation]. University of Cambridge; 2011. Available from: http://www.dspace.cam.ac.uk/handle/1810/239351https://www.repository.cam.ac.uk/bitstream/1810/239351/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/3/thesis_compiler.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/239351/4/thesis_compiler.pdf.jpg

University of Manitoba

18. Hallas, Alannah. Ho2Ge2O7 and Pr2Zr2O7: a tale of two spin ices.

Degree: Chemistry, 2013, University of Manitoba

URL: http://hdl.handle.net/1993/22205

► The spin ice state is a rare magnetic ground state that can be observed in the pyrochlore oxides, A2B2O7. In this ground state, the spins,… (more)

Subjects/Keywords: magnetism; frustrated

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APA (6^th Edition):

Hallas, A. (2013). Ho2Ge2O7 and Pr2Zr2O7: a tale of two spin ices. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/22205

Chicago Manual of Style (16^th Edition):

Hallas, Alannah. “Ho2Ge2O7 and Pr2Zr2O7: a tale of two spin ices.” 2013. Masters Thesis, University of Manitoba. Accessed March 07, 2021. http://hdl.handle.net/1993/22205.

MLA Handbook (7^th Edition):

Hallas, Alannah. “Ho2Ge2O7 and Pr2Zr2O7: a tale of two spin ices.” 2013. Web. 07 Mar 2021.

Vancouver:

Hallas A. Ho2Ge2O7 and Pr2Zr2O7: a tale of two spin ices. [Internet] [Masters thesis]. University of Manitoba; 2013. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1993/22205.

Council of Science Editors:

Hallas A. Ho2Ge2O7 and Pr2Zr2O7: a tale of two spin ices. [Masters Thesis]. University of Manitoba; 2013. Available from: http://hdl.handle.net/1993/22205

University of Oxford

19. Tock, Calvin. Studies in magnon spintronics.

Degree: PhD, 2017, University of Oxford

URL: http://ora.ox.ac.uk/objects/uuid:0aaea652-602f-4478-a0f7-4247a8ba382f ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.780412

► This thesis is a thesis of two halves. The first investigates the Spintronic idea of generating charge-decoupled spin currents in metallic systems, whereas the second… (more)

Subjects/Keywords: Magnetism; Physics

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APA (6^th Edition):

Tock, C. (2017). Studies in magnon spintronics. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:0aaea652-602f-4478-a0f7-4247a8ba382f ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.780412

Chicago Manual of Style (16^th Edition):

Tock, Calvin. “Studies in magnon spintronics.” 2017. Doctoral Dissertation, University of Oxford. Accessed March 07, 2021. http://ora.ox.ac.uk/objects/uuid:0aaea652-602f-4478-a0f7-4247a8ba382f ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.780412.

MLA Handbook (7^th Edition):

Tock, Calvin. “Studies in magnon spintronics.” 2017. Web. 07 Mar 2021.

Vancouver:

Tock C. Studies in magnon spintronics. [Internet] [Doctoral dissertation]. University of Oxford; 2017. [cited 2021 Mar 07]. Available from: http://ora.ox.ac.uk/objects/uuid:0aaea652-602f-4478-a0f7-4247a8ba382f ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.780412.

Council of Science Editors:

Tock C. Studies in magnon spintronics. [Doctoral Dissertation]. University of Oxford; 2017. Available from: http://ora.ox.ac.uk/objects/uuid:0aaea652-602f-4478-a0f7-4247a8ba382f ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.780412

Michigan State University

20. McElearney, James Nathaniel. Low Temperature adiabatic studies of magnetic phase boundaries in antiferromagnets.

Degree: PhD, Department of Physics, 1968, Michigan State University

URL: http://etd.lib.msu.edu/islandora/object/etd:35593

Subjects/Keywords: Magnetism

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APA (6^th Edition):

McElearney, J. N. (1968). Low Temperature adiabatic studies of magnetic phase boundaries in antiferromagnets. (Doctoral Dissertation). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:35593

Chicago Manual of Style (16^th Edition):

McElearney, James Nathaniel. “Low Temperature adiabatic studies of magnetic phase boundaries in antiferromagnets.” 1968. Doctoral Dissertation, Michigan State University. Accessed March 07, 2021. http://etd.lib.msu.edu/islandora/object/etd:35593.

MLA Handbook (7^th Edition):

McElearney, James Nathaniel. “Low Temperature adiabatic studies of magnetic phase boundaries in antiferromagnets.” 1968. Web. 07 Mar 2021.

Vancouver:

McElearney JN. Low Temperature adiabatic studies of magnetic phase boundaries in antiferromagnets. [Internet] [Doctoral dissertation]. Michigan State University; 1968. [cited 2021 Mar 07]. Available from: http://etd.lib.msu.edu/islandora/object/etd:35593.

Council of Science Editors:

McElearney JN. Low Temperature adiabatic studies of magnetic phase boundaries in antiferromagnets. [Doctoral Dissertation]. Michigan State University; 1968. Available from: http://etd.lib.msu.edu/islandora/object/etd:35593

21. Goruganti, Venkat. Transport and magnetic properties of rtx and related.

Degree: PhD, Physics, 2009, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-3227

► Physical properties of RTX compounds (R = Rare earth, T = Transition metal and X = main group element from B, C or N group)… (more)

▼ Physical properties of RTX compounds (R = Rare earth, T = Transition metal and X = main group element from B, C or N group) compounds have been studied by means of electrical resistivity, heat capacity, dc magnetization and NMR. Searching for new magnetic materials is always an interesting topic from both a technological and basic research prospective; it is even more interesting when unusual magnetic phases are observed. Ternary intermetallic plumbides are interesting because of their unconventional magnetic ordering and variety of multiple magnetic transitions. Crystalline electric fields (CEF) also strongly effect the magnetic properties of these intermetallics. To understand the phase transitions, CEF effects, and magnetic interactions, a systematic study of the RNiPb, R2Ni2Pb, R5NiPb3 and RCuGe systems were conducted. Among the results for NdNiPb a single antiferromagnetic transition was found at 3.5K, while the superconductivity found in some ingots of this material was shown not to correspond to a bulk behavior for this phase. Nd2Ni2Pb was shown to have a canted zero field magnetic structure with a low temperature metamagnetic transition 3 T. In NdCuGe, a 3K AF transition was found along with a corresponding magnon contribution to the specific heat and magnetic and thermodynamic behavior from which the detailed CEF configuration was obtained. In a series of measurements on recently-synthesized R5NiPb3 (R=Ce, Nd, Gd), for Ce5NiPb3 a transition at 48 K was found, which was confirmed to be ferromagnetic character from field dependent heat capacity and Curie-Weiss susceptibility. Nd5NiPb3 exhibits two transitions, an antiferromagnetic transition at 42 K and an apparently weak ferromagnetic canting transition at 8 K. For Gd5NiPb3, a ferro- or ferrimagnetic transition was found at 68 K. For the Ce and Nd materials metamagnetism was also observed at low temperatures. In addition, very large metallic type y terms were found in the specific heat, as well as a reduced value of the magnetic entropy, for all three systems. These results imply a lack of ordering for one of the two in-equivalent chains in these materials. This is discussed in terms of possible geometrical frustration on one of the spin chains. Advisors/Committee Members: Ross, Jr., Joseph H. (advisor), Agnolet, Glenn (committee member), Naugle, Donald G. (committee member), Schaak, Raymond E. (committee member).

Subjects/Keywords: magnetism

…20 . . . . . . . . . . . . . . . . . . . . . . . . MAGNETISM… …x28;2.21) 20 CHAPTER III MAGNETISM In this chapter I introduce some magnetism basics… …fundamental quantity in magnetism is the magnetic moment defined as µ = γJ, where γ is the… …origin of magnetism, one has to consider the orbital motions and spin motions of electrons and…

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APA (6^th Edition):

Goruganti, V. (2009). Transport and magnetic properties of rtx and related. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-3227

Chicago Manual of Style (16^th Edition):

Goruganti, Venkat. “Transport and magnetic properties of rtx and related.” 2009. Doctoral Dissertation, Texas A&M University. Accessed March 07, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-3227.

MLA Handbook (7^th Edition):

Goruganti, Venkat. “Transport and magnetic properties of rtx and related.” 2009. Web. 07 Mar 2021.

Vancouver:

Goruganti V. Transport and magnetic properties of rtx and related. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3227.

Council of Science Editors:

Goruganti V. Transport and magnetic properties of rtx and related. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3227

University of British Columbia

22. Fink, Hermann Josef. Precision frequency control of a magnetic storage drum.

Degree: Master of Applied Science - MASc, Electrical and Computer Engineering, 1956, University of British Columbia

URL: http://hdl.handle.net/2429/40348

► In the development of a pulse position modulation analogue computer the requirement arose to control accurately the frequency of a magnetic drum. A control system… (more)

Subjects/Keywords: Magnetism

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APA (6^th Edition):

Fink, H. J. (1956). Precision frequency control of a magnetic storage drum. (Masters Thesis). University of British Columbia. Retrieved from http://hdl.handle.net/2429/40348

Chicago Manual of Style (16^th Edition):

Fink, Hermann Josef. “Precision frequency control of a magnetic storage drum.” 1956. Masters Thesis, University of British Columbia. Accessed March 07, 2021. http://hdl.handle.net/2429/40348.

MLA Handbook (7^th Edition):

Fink, Hermann Josef. “Precision frequency control of a magnetic storage drum.” 1956. Web. 07 Mar 2021.

Vancouver:

Fink HJ. Precision frequency control of a magnetic storage drum. [Internet] [Masters thesis]. University of British Columbia; 1956. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/2429/40348.

Council of Science Editors:

Fink HJ. Precision frequency control of a magnetic storage drum. [Masters Thesis]. University of British Columbia; 1956. Available from: http://hdl.handle.net/2429/40348

Michigan State University

23. Doser, Manfred. Magnetic interactions between Co₅Sm and iron cobalt fine particle composites.

Degree: MS, Dept. of Metallurgy, Mechanics, and Materials Science, 1971, Michigan State University

URL: http://etd.lib.msu.edu/islandora/object/etd:10588

Subjects/Keywords: Magnetism

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APA (6^th Edition):

Doser, M. (1971). Magnetic interactions between Co₅Sm and iron cobalt fine particle composites. (Masters Thesis). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:10588

Chicago Manual of Style (16^th Edition):

Doser, Manfred. “Magnetic interactions between Co₅Sm and iron cobalt fine particle composites.” 1971. Masters Thesis, Michigan State University. Accessed March 07, 2021. http://etd.lib.msu.edu/islandora/object/etd:10588.

MLA Handbook (7^th Edition):

Doser, Manfred. “Magnetic interactions between Co₅Sm and iron cobalt fine particle composites.” 1971. Web. 07 Mar 2021.

Vancouver:

Doser M. Magnetic interactions between Co₅Sm and iron cobalt fine particle composites. [Internet] [Masters thesis]. Michigan State University; 1971. [cited 2021 Mar 07]. Available from: http://etd.lib.msu.edu/islandora/object/etd:10588.

Council of Science Editors:

Doser M. Magnetic interactions between Co₅Sm and iron cobalt fine particle composites. [Masters Thesis]. Michigan State University; 1971. Available from: http://etd.lib.msu.edu/islandora/object/etd:10588

24. Lee-Brown, Donald. The Lithium Plateau in Super Metal-Rich Stars.

Degree: PhD, Physics & Astronomy, 2018, University of Kansas

URL: http://hdl.handle.net/1808/28006

► I present a study of the lithium abundances for a sample of super metal-rich (SMR, [Fe/H] > + 0.20) main sequence dwarfs in the solar… (more)

▼ I present a study of the lithium abundances for a sample of super metal-rich (SMR, [Fe/H] > + 0.20) main sequence dwarfs in the solar neighborhood. The SMR stars were selected to have surface temperatures in the region of the lithium plateau, a narrow region in temperature space where stars are predicted by models to preserve their initial surface Li abundances while on the main sequence. Despite these predictions, observations of lower-metallicity stars indicate that significant depletion occurs during the first few Gyr of stellar evolution. SMR stars, which represent the extreme end of Galactic chemical evolution, present an opportunity to constrain proposed mechanisms to explain this depletion. 100 SMR candidates were selected from existing surveys and followed up with spectroscopic observations using the Hydra spectrograph on the WIYN 3.5m telescope at Kitt Peak National Observatory, as well as photometric observations using the 0.9m WIYN and 40” telescopes at Kitt Peak and Mount Laguna Observatory, respectively. Using the results from ANNA, a new tool that uses a neural network to parameterize stellar spectra, as well as a more traditional equivalent width based analysis, 44 single stars with [Fe/H] > + 0.20 were identified and Li was measured for each star. Consistent with previous studies, the SMR stars can be divided into a sample of stars with measurable Li and a sample with upper limits only. Examining the low-Li stars’ evolutionary states reveals that they are consistent with being evolved Li dip stars and therefore depleted their surface Li while on the main sequence before evolving to the cooler temperatures of the Li plateau. Considering only the high-Li sample, the stars are all consistent with having ages in the range 3 – 4.5 Gyr, indicating that they have already significantly depleted their Li. We find no young (age + 0.20) main sequence dwarfs in the solar neighborhood. The SMR stars were selected to have surface temperatures in the region of the lithium plateau, a narrow region in temperature space where stars are predicted by models to preserve their initial surface Li abundances while on the main sequence. Despite these predictions, observations of lower-metallicity stars indicate that significant depletion occurs during the first few Gyr of stellar evolution. SMR stars, which represent the extreme end of Galactic chemical evolution, present an opportunity to constrain proposed mechanisms to explain this depletion. 100 SMR candidates were selected from existing surveys and followed up with spectroscopic observations using the Hydra spectrograph on the WIYN 3.5m telescope at Kitt Peak National Observatory, as well as photometric observations using the 0.9m WIYN and 40” telescopes at Kitt Peak and Mount Laguna Observatory, respectively. Using the results from ANNA, a new tool that uses a neural network to parameterize stellar spectra, as well as a more traditional equivalent width based analysis, 44 single stars with [Fe/H] > + 0.20 were identified and Li was measured for each star. Consistent… Advisors/Committee Members: Twarog, Bruce (advisor), Anthony-Twarog, Barbara (cmtemember), Rudnick, Gregory (cmtemember), Sanders, Stephen (cmtemember), Mechem, David (cmtemember).

Subjects/Keywords: Astronomy; Astrophysics; Field Stars; Lithium; Stellar Abundances; Stellar Spectroscopy; Stellar Structure; Super Metal-Rich Stars

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APA (6^th Edition):

Lee-Brown, D. (2018). The Lithium Plateau in Super Metal-Rich Stars. (Doctoral Dissertation). University of Kansas. Retrieved from http://hdl.handle.net/1808/28006

Chicago Manual of Style (16^th Edition):

Lee-Brown, Donald. “The Lithium Plateau in Super Metal-Rich Stars.” 2018. Doctoral Dissertation, University of Kansas. Accessed March 07, 2021. http://hdl.handle.net/1808/28006.

MLA Handbook (7^th Edition):

Lee-Brown, Donald. “The Lithium Plateau in Super Metal-Rich Stars.” 2018. Web. 07 Mar 2021.

Vancouver:

Lee-Brown D. The Lithium Plateau in Super Metal-Rich Stars. [Internet] [Doctoral dissertation]. University of Kansas; 2018. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1808/28006.

Council of Science Editors:

Lee-Brown D. The Lithium Plateau in Super Metal-Rich Stars. [Doctoral Dissertation]. University of Kansas; 2018. Available from: http://hdl.handle.net/1808/28006

25. Pande, Seetesh. Analysis of spacecraft trajectories on the polar axis over the event horizon of a stellar originated rotating kerr black hole; -.

Degree: Aerospace Engineering, 2013, University of Petroleum and Energy Studies (UPES)

URL: http://shodhganga.inflibnet.ac.in/handle/10603/41384

Abstract avalible

References p.116 - 120 and Appendix p.121 - 129

Advisors/Committee Members: Ugur, Guven.

Subjects/Keywords: Spacecraft; Stellar

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APA (6^th Edition):

Pande, S. (2013). Analysis of spacecraft trajectories on the polar axis over the event horizon of a stellar originated rotating kerr black hole; -. (Thesis). University of Petroleum and Energy Studies (UPES). Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/41384

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Pande, Seetesh. “Analysis of spacecraft trajectories on the polar axis over the event horizon of a stellar originated rotating kerr black hole; -.” 2013. Thesis, University of Petroleum and Energy Studies (UPES). Accessed March 07, 2021. http://shodhganga.inflibnet.ac.in/handle/10603/41384.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Pande, Seetesh. “Analysis of spacecraft trajectories on the polar axis over the event horizon of a stellar originated rotating kerr black hole; -.” 2013. Web. 07 Mar 2021.

Vancouver:

Pande S. Analysis of spacecraft trajectories on the polar axis over the event horizon of a stellar originated rotating kerr black hole; -. [Internet] [Thesis]. University of Petroleum and Energy Studies (UPES); 2013. [cited 2021 Mar 07]. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/41384.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Pande S. Analysis of spacecraft trajectories on the polar axis over the event horizon of a stellar originated rotating kerr black hole; -. [Thesis]. University of Petroleum and Energy Studies (UPES); 2013. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/41384

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Vanderbilt University

26. Garcia, Eugenio Victor. Astrophysical Laboratories and Advanced Imaging Techniques for Testing Stellar Models: Eclipsing Binaries, High Contrast Imaging, and Optical Interferometry.

Degree: PhD, Physics, 2016, Vanderbilt University

URL: http://hdl.handle.net/1803/12121

► In chapter 1, we determine the masses, radii and temperatures of the eclipsing binary V578 Mon, a detached system of two early B-type stars in… (more)

▼ In chapter 1, we determine the masses, radii and temperatures of the eclipsing binary V578 Mon, a detached system of two early B-type stars in the Rosette Nebula, to better than 5% accuracy. We compare these measurements to the stellar models of the Geneva, Utrecht and Granada group. We find all three sets of models marginally reproduce the absolute dimensions of both stars. However - there are some apparent discrepancies, and the Utrecht models worked best. We also compute the combined internal structure constants for V578 Mon. We find that the predicted internal structure constants of the Granada models fully agrees with our observations. In chapter 2, we present the results of a Hubble Space Telescope survey of the lowest mass brown dwarfs in the Pleiades. These objects represent the predecessors to T-dwarfs in the field. Using a new PSF-fitting technique, we are able to probe to 30 milliarcseconds, better than 2× the HST diffraction limit. We did not find any companions to our targets. Our survey is the first to attain the high angular resolution needed to resolve brown dwarf binaries in the Pleiades at separations that are most common in the field population. We constrain the binary frequency to be <26% at 2σ. This binary frequency is consistent with both younger and older brown dwarfs in this mass range and with brown dwarf formation models. Visible-light long baseline interferometry holds the promise of advancing a number of important applications in fundamental astronomy, including the direct measurement of the angular diameters and oblateness of stars, and the orbits of binary and multiple star systems. To advance, the field requires instruments capable of combining light from 6 telescopes simultaneously. In chapter 3, we present the Visible Imaging System for Interferometric Observations at NPOI (VISION) is a new visible light beam combiner for the Navy Precision Optical Interferometer (NPOI) that coherently combines light from up to six telescopes simultaneously. We detail the commissioning of VISION with laboratory and on-sky tests. We provide a new set of corrections for the power spectrum and bispectrum when using EMCCDs. Advisors/Committee Members: Professor Keivan Stassun (committee member), Dr. Gerard van Belle (committee member), Professor Andreas Berlind (committee member), Professor Kelly Holley-Bocklemann (committee member), Professor Robert Scherrer (committee member).

Subjects/Keywords: brown dwarfs; stellar evolution; interferometry

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APA (6^th Edition):

Garcia, E. V. (2016). Astrophysical Laboratories and Advanced Imaging Techniques for Testing Stellar Models: Eclipsing Binaries, High Contrast Imaging, and Optical Interferometry. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12121

Chicago Manual of Style (16^th Edition):

Garcia, Eugenio Victor. “Astrophysical Laboratories and Advanced Imaging Techniques for Testing Stellar Models: Eclipsing Binaries, High Contrast Imaging, and Optical Interferometry.” 2016. Doctoral Dissertation, Vanderbilt University. Accessed March 07, 2021. http://hdl.handle.net/1803/12121.

MLA Handbook (7^th Edition):

Garcia, Eugenio Victor. “Astrophysical Laboratories and Advanced Imaging Techniques for Testing Stellar Models: Eclipsing Binaries, High Contrast Imaging, and Optical Interferometry.” 2016. Web. 07 Mar 2021.

Vancouver:

Garcia EV. Astrophysical Laboratories and Advanced Imaging Techniques for Testing Stellar Models: Eclipsing Binaries, High Contrast Imaging, and Optical Interferometry. [Internet] [Doctoral dissertation]. Vanderbilt University; 2016. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1803/12121.

Council of Science Editors:

Garcia EV. Astrophysical Laboratories and Advanced Imaging Techniques for Testing Stellar Models: Eclipsing Binaries, High Contrast Imaging, and Optical Interferometry. [Doctoral Dissertation]. Vanderbilt University; 2016. Available from: http://hdl.handle.net/1803/12121

Queens University

27. David-Uraz, Alexandre. Investigating the potential magnetic origin of wind variability in OB stars .

Degree: Physics, Engineering Physics and Astronomy, 2016, Queens University

URL: http://hdl.handle.net/1974/14445

► In this thesis, the origin of large-scale structures in hot star winds, believed to be responsible for the presence of discrete absorption components (DACs) in… (more)

▼ In this thesis, the origin of large-scale structures in hot star winds, believed to be responsible for the presence of discrete absorption components (DACs) in the absorption troughs of ultraviolet resonance lines, is constrained using both observations and numerical simulations. These structures are understood as arising from bright regions on the stellar surface, although their physical cause remains unknown. First, we use high quality circular spectropolarimetric observations of 13 well-studied OB stars to evaluate the potential role of dipolar magnetic fields in producing DACs. We perform longitudinal field measurements and place limits on the field strength using Bayesian inference, assuming that it is dipolar. No magnetic field was detected within this sample. The derived constraints statistically refute any significant dynamical influence from a magnetic dipole on the wind for all of these stars, ruling out such fields as a cause for DACs. Second, we perform numerical simulations using bright spots constrained by broadband optical photometric observations. We calculate hydrodynamical wind models using three sets of spot sizes and strengths. Co-rotating interaction regions are yielded in each model, and radiative transfer shows that the properties of the variations in the UV resonance lines synthesized from these models are consistent with those found in observed UV spectra, establishing the first consistent link between UV spectroscopic line profile variability and photometric variations and thus supporting the bright spot paradigm (BSP). Finally, we develop and apply a phenomenological model to quantify the measurable effects co-rotating bright spots would have on broadband optical photometry and on the profiles of photopheric lines in optical spectra. This model can be used to evaluate the existence of these spots, and, in the event of their detection, characterize them. Furthermore, a tentative spot evolution model is presented. A preliminary analysis of its output, compared to the observed photometric variations of xi Persei, suggests the possible existence of “active longitudes” on the surface of this star. Future work will expand the range of observational diagnostics that can be interpreted within the BSP, and link phenomenology (bright spots) to physical processes (magnetic spots or non-radial pulsations).

Subjects/Keywords: astrophysics ; stellar winds ; massive stars

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APA (6^th Edition):

David-Uraz, A. (2016). Investigating the potential magnetic origin of wind variability in OB stars . (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/14445

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

David-Uraz, Alexandre. “Investigating the potential magnetic origin of wind variability in OB stars .” 2016. Thesis, Queens University. Accessed March 07, 2021. http://hdl.handle.net/1974/14445.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

David-Uraz, Alexandre. “Investigating the potential magnetic origin of wind variability in OB stars .” 2016. Web. 07 Mar 2021.

Vancouver:

David-Uraz A. Investigating the potential magnetic origin of wind variability in OB stars . [Internet] [Thesis]. Queens University; 2016. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/1974/14445.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

David-Uraz A. Investigating the potential magnetic origin of wind variability in OB stars . [Thesis]. Queens University; 2016. Available from: http://hdl.handle.net/1974/14445

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

28. Giridhar, Sunetra. Studies in stellar spectroscopy; -.

Degree: Astrophysics, 1982, Pt. Ravishankar Shukla University

URL: http://shodhganga.inflibnet.ac.in/handle/10603/43174

None

Bibliography p.209-221

Advisors/Committee Members: Bhattacharya, J C.

Subjects/Keywords: spectroscopy; stellar

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APA (6^th Edition):

Giridhar, S. (1982). Studies in stellar spectroscopy; -. (Thesis). Pt. Ravishankar Shukla University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/43174

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Giridhar, Sunetra. “Studies in stellar spectroscopy; -.” 1982. Thesis, Pt. Ravishankar Shukla University. Accessed March 07, 2021. http://shodhganga.inflibnet.ac.in/handle/10603/43174.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Giridhar, Sunetra. “Studies in stellar spectroscopy; -.” 1982. Web. 07 Mar 2021.

Vancouver:

Giridhar S. Studies in stellar spectroscopy; -. [Internet] [Thesis]. Pt. Ravishankar Shukla University; 1982. [cited 2021 Mar 07]. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/43174.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Giridhar S. Studies in stellar spectroscopy; -. [Thesis]. Pt. Ravishankar Shukla University; 1982. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/43174

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Harvard University

29. Gu, Meng. Stellar Populations and Assembly Histories of Galaxies in Nearby Massive Clusters.

Degree: PhD, 2019, Harvard University

URL: http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029709

► Understanding how massive galaxies form and grow is of profound importance to modern theories of galaxy evolution and cosmology. In this thesis, I investigate the… (more)

▼ Understanding how massive galaxies form and grow is of profound importance to modern theories of galaxy evolution and cosmology. In this thesis, I investigate the stellar population and assembly histories of massive galaxies and their surrounding satellite galaxies in nearby galaxy clusters, with particular focus on how they maintain the remarkable scaling relations among their stellar mass, their stellar population properties, and the mass of their host dark matter halos regardless of the stochastic mergers and the complex baryonic processes they experienced. I begin by introducing the “coordinated assembly” picture for massive galaxies using an ongoing brightest cluster (BCG) assembly case at z ∼ 0.1. With detailed stellar population analysis, we look into both the scaling relations between stellar mass and galaxy central stellar population properties, as well as the radial profiles where their stellar population bear the imprint of the assembly history. We found that the cluster center shapes the [α/Fe]–σ⋆ and [α/Fe]–M⋆ relations differently than other environments, suggesting the assembly of massive galaxies is coordinated in a way that their building blocks are not just random draws from the general low mass galaxy population, but featuring early truncated star formation histories, making them a special sample among the general population. Next, I present a deep and comprehensive optical spectroscopic survey of galaxies in the Coma cluster–the Deep Coma project. This is part of the SDSS IV/MaNGA Survey. Taking advantage of the deep integral field spectroscopy and the powerful full spectral modeling method, we investigated the stellar population in various types of targets, in addition to central and outskirts of BCGs and massive early type galaxies. In particular, our results show that the stellar populations of intracluster light (ICL) are old and metal poor, indicating the build-up of ICL in Coma is likely to be through the accretion of low mass galaxies or the tidal stripping of the outskirts of massive galaxies that have ended their star formation early on. The old and shallow radial profiles of stellar age from the BCG centers to ICL are also consistent with the “coordinated assembly” picture. Mean- while, we find that the ultra-diffuse galaxies (UDGs) in Coma have as old or older stellar age than galaxies at similar stellar mass or velocity dispersion. Despite their diffuse structures and their un- usual large size, they in general follow the well-established M⋆–stellar metallicity relation, with one exception lies below the σ⋆-metallicity relation, suggesting that stellar mass plays a more important role in setting stellar population properties for these galaxies than either size or surface brightness. In Chapter 5, I look into the stellar mass-halo mass relation, and investigate the origins of its scatter, by combining N-body simulations with observational constraints. We find that at the group and cluster scale, the scatter is mostly due to hierarchical assembly. At lower masses, in situ buildup of… Advisors/Committee Members: Conroy, Charles (advisor), Caldwell, Nelson (committee member), Eisenstein, Daniel (committee member), van Dokkum, Pieter (committee member).

Subjects/Keywords: galaxy evolution; stellar population

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gu, M. (2019). Stellar Populations and Assembly Histories of Galaxies in Nearby Massive Clusters. (Doctoral Dissertation). Harvard University. Retrieved from http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029709

Chicago Manual of Style (16^th Edition):

Gu, Meng. “Stellar Populations and Assembly Histories of Galaxies in Nearby Massive Clusters.” 2019. Doctoral Dissertation, Harvard University. Accessed March 07, 2021. http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029709.

MLA Handbook (7^th Edition):

Gu, Meng. “Stellar Populations and Assembly Histories of Galaxies in Nearby Massive Clusters.” 2019. Web. 07 Mar 2021.

Vancouver:

Gu M. Stellar Populations and Assembly Histories of Galaxies in Nearby Massive Clusters. [Internet] [Doctoral dissertation]. Harvard University; 2019. [cited 2021 Mar 07]. Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029709.

Council of Science Editors:

Gu M. Stellar Populations and Assembly Histories of Galaxies in Nearby Massive Clusters. [Doctoral Dissertation]. Harvard University; 2019. Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029709

30. Duivenvoorden, Steven. Unravelling the influence of environment, redshift and confusion on the star formation in dusty galaxies.

Degree: PhD, 2018, University of Sussex

URL: http://sro.sussex.ac.uk/id/eprint/77363/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751895

► Over the last three decades, the far-infrared emission from distant galaxies has been revealed to us. This far-infrared light is emitted by dust clouds heated… (more)

▼ Over the last three decades, the far-infrared emission from distant galaxies has been revealed to us. This far-infrared light is emitted by dust clouds heated by UV radiation from young stars. This reveals to us some of the most remarkable and highly star-forming galaxies in the Universe. The Herschel space observatory was able to capture this light. With this thesis I have attempted to get a better understanding of the underlying galaxy population. I have done this by observing the most extreme forms of star formation in the early Universe seen in maps obtained by the SPIRE instrument and using prior information from deep high resolution surveys. In particular I have examined the dependencies of dusty galaxy properties on their environment. I have confirmed that star formation is primarily dependent on both galaxy mass and whether a galaxy lies in the "blue cloud". Environment is the primary influence on the fraction of galaxies lying in the blue cloud and has a minor, but significant, affect on the average star formation rate of star forming galaxies. The highest redshift galaxies directly detected in the Herschel SPIRE maps are very rare, but due to the large area of the HerMES surveys we are able to find a statistical significant sample. With the addition of longer wavelength SCUBA-2 data I further confine the redshift of the dusty galaxies and find that the star formation rates of those sources are extremely high and exceed 1000 M_ a year. The observed number counts of these extremely bright sources have been a problem for galaxy evolution models. I am able to explain the observed number count of red SPIRE sources by adding correlated confusion noise and Gaussian instrumental noise to simulated galaxy catalogues. My results emphasise that it is crucial to correct for noise and selection effects for comparison with simulations. I exploit a novel way of fitting the full SPIRE maps using prior information from deep high resolution surveys, obtained from wavelengths ranging from optical to radio. In doing so I obtain the most accurate values of the cosmic infrared background (CIB) at the SPIRE wavelengths. With these results we have a better indication of which sources are producing the CIB, and therefore the bulk of star formation. My results indicate that future large area surveys like LSST are likely to resolve a substantial fraction of the population responsible for the CIB at 250 μm ≤ λ ≤ 500 μm.

Subjects/Keywords: 520; QB0806 Stellar evolution

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Duivenvoorden, S. (2018). Unravelling the influence of environment, redshift and confusion on the star formation in dusty galaxies. (Doctoral Dissertation). University of Sussex. Retrieved from http://sro.sussex.ac.uk/id/eprint/77363/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751895

Chicago Manual of Style (16^th Edition):

Duivenvoorden, Steven. “Unravelling the influence of environment, redshift and confusion on the star formation in dusty galaxies.” 2018. Doctoral Dissertation, University of Sussex. Accessed March 07, 2021. http://sro.sussex.ac.uk/id/eprint/77363/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751895.

MLA Handbook (7^th Edition):

Duivenvoorden, Steven. “Unravelling the influence of environment, redshift and confusion on the star formation in dusty galaxies.” 2018. Web. 07 Mar 2021.

Vancouver:

Duivenvoorden S. Unravelling the influence of environment, redshift and confusion on the star formation in dusty galaxies. [Internet] [Doctoral dissertation]. University of Sussex; 2018. [cited 2021 Mar 07]. Available from: http://sro.sussex.ac.uk/id/eprint/77363/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751895.

Council of Science Editors:

Duivenvoorden S. Unravelling the influence of environment, redshift and confusion on the star formation in dusty galaxies. [Doctoral Dissertation]. University of Sussex; 2018. Available from: http://sro.sussex.ac.uk/id/eprint/77363/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.751895

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