Browsing FAS Theses and Dissertations by FAS Department "Astronomy"
Now showing items 21-40 of 71
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From Stars to Galaxies: Unveiling Their Properties, Connection, and Evolution With Next Generation Stellar Models
(2018-05-11)Many areas of astrophysics spanning orders of magnitudes in physical scales—from exoplanets to high-redshift galaxies—are deeply rooted in our interpretation of light emitted by stars. Thus the importance of a well-tested ... -
Fueling Galaxy Growth Through Gas Accretion in Cosmological Simulations
(2015-05-17)Despite significant advances in the numerical modeling of galaxy formation and evolution, it is clear that a satisfactory theoretical picture of how galaxies acquire their baryons across cosmic time remains elusive. In ... -
The Fundamental Properties of Young Stars
(2016-05-18)Accurate knowledge of the fundamental properties of stars--mass, temperature, and luminosity--is key to our understanding of stellar evolution. In particular, empirical measurements of stellar mass are difficult to make ... -
Galactic Conformity via Small-Scale Clustering in Simulations and Surveys
(2016-05-14)Data from recent galaxy surveys reveal that, even at fixed stellar mass, quiescent galaxies are preferentially found around other red galaxies, an observation referred to as galactic conformity. This detection may offer ... -
Galaxy Mergers and Some Consequences: The Cosmological Context
(2016-05-18)The last few years have seen enormous progress in the field of galaxy formation and evolution. The latest generation of hydrodynamic cosmological simulations (e.g., the "Illustris" simulation) has been able to produce ... -
How I Learned to Stop Worrying and Love Eclipsing Binaries
(2015-09-01)Relatively massive B-type stars with closely orbiting stellar companions can evolve to produce Type Ia supernovae, X-ray binaries, millisecond pulsars, mergers of neutron stars, gamma ray bursts, and sources of gravitational ... -
Hues of Habitability: Characterizing Pale Blue Dots Around Other Stars
(2015-05-16)A wide range of potentially rocky transiting planets in the habitable zone (HZ) have been detected by Kepler as well as ground-based searches. The spectral type of the host star will influence our ability to detect atmospheric ... -
In Pursuit of New Worlds: Searches for and Studies of Transiting Exoplanets from Three Space-Based Observatories
(2012-07-23)This thesis presents studies of transiting exoplanets using observations gathered in large part from space, with the NASA EPOXI Mission, the Spitzer Space Telescope, and the Kepler Mission. The first part of this thesis ... -
Infrared Light Curves of Type Ia Supernovae
(2012-09-12)This thesis presents the CfAIR2 data set, which includes over 4000 near-Infrared (NIR) \(JHK_s\)-band measurements of 104 Type Ia Supernovae (SN Ia) observed from 2005-2011 using PAIRITEL, the 1.3-m Peters Automated InfraRed ... -
Instability-Driven Limits on Ion Temperature Anisotropy in the Solar Wind: Observations and Linear Vlasov Theory
(2012-09-12)Kinetic microinstabilities in the solar wind arise when its non-thermal properties become too extreme. This thesis project focused specifically on the four instabilities associated with ion temperature anisotropy: the ... -
Interior Structure and Chemistry of Solid Exoplanets
(2015-05-08)Understanding the interior structures and chemistry of Earth-like exoplanets is crucial for us to characterize exoplanets, and to find potentially habitable planets. First, I provide a model grid of the mass-radius ... -
Long-Term Dynamics of High Mass Ratio Multiples
(2015-05-15)This thesis presents a series of studies on the dynamics of high mass ratio multiples, with applications to planetary systems orbiting stars and stellar systems orbiting supermassive black holes (SMBHs). Almost two ... -
Magnetic Fields in the Milky Way and the Magellanic Clouds
(2013-02-25)This thesis is an observational investigation into the origin of large-scale coherent magnetic fields in the Milky Way and the Magellanic Clouds. I use Faraday rotation measure of both polarized extragalactic sources and ... -
Magnetic Influences on the Solar Wind
(2016-05-12)The steady, supersonic outflow from the Sun we call the solar wind was first posited in the 1950s and initial theories rightly linked the acceleration of the wind to the existence of the million-degree solar corona. Still ... -
Mapping Milky Way Dust in 3D With Stellar Photometry
(2016-05-18)I present a three-dimensional map of interstellar dust reddening, covering three-quarters of the sky out to a distance of several kiloparsecs, based on Pan-STARRS 1 and 2MASS photometry. The map reveals a wealth of detailed ... -
Massive Black-Hole Binary Mergers: Dynamics, Environments & Expected Detections
(2018-05-13)This thesis studies the populations and dynamics of massive black-hole binaries and their mergers, and explores the implications for electromagnetic and gravitational-wave signals that will be detected in the near future. ... -
Massive Compact Galaxies: A Case Study of the Diversity of Evolutionary Pathways in Cosmological Simulations
(2017-05-11)Observations of the high-redshift Universe have revealed a population of remarkably dense massive quiescent galaxies at z~2. These objects have already formed 10^11 Msun of stars but have radii of only 1-2 kpc, approximately ... -
Millimeter Studies of Nearby Debris Disks
(2017-05-10)At least 20% of nearby main sequence stars are known to be surrounded by disks of dusty material resulting from the collisional erosion of planetesimals, similar to asteroids and comets in our own Solar System. The material ... -
Millimeter/submillimeter Observations of Chemical and Physical Complexity in Protoplanetary Disks
(2018-05-13)Dust and gas rich protoplanetary disks are the formation sites of planets, and are virtually ubiquitous around young (<1 Myr) stars. Understanding these environments is crucial to determining future exoplanet compositions, ... -
Modeling and Simulation of Circumstellar Disks with the Next Generation of Hydrodynamic Solvers
(2013-10-18)This thesis is a computational study of circumstellar gas disks, with a special focus on modeling techniques and on numerical methods not only as scientific tools but also as a target of study. In particular, in-depth ...