In this thesis I study and measure the spatial distribution of galaxies selected in optical and near-infrared surveys over cosmic time. By measuring the clustering of these sources, valuable insight can be gained into the role of environment in shaping galaxy evolution over the history of the Universe. I present a series of results from a clustering analysis of the first data release of the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey. VIDEO is the only survey currently capable of probing the bulk of stellar mass in galaxies at redshifts corresponding to the peak of star formation on degree scales. Galaxy clustering is measured with the two-point correlation function, which is calculated using a non para- metric kernel based density estimator. I use my measurements to investigate the connection between the galaxies and the host dark matter halo using a Halo Occupation Distribution (HOD) methodology, deriving bias, satellite fractions, and typical host halo masses for stellar masses between 10^9.35M_⊙ and 10^10.85M_⊙, at redshifts 0.5 < z < 1.7. I show that the typical halo mass increases with stellar mass (with moderate scatter) and bias also increases with stellar mass and redshift, consistent with previous studies. I find the satellite fraction increases towards low redshifts, from ∼ 5% at z ∼ 1.5, to ∼ 20% at z ∼ 0.6, also increasing for lower mass galaxies. I combine my results to derive the stellar mass to halo mass ratio for both satellites and centrals over a range of halo masses and find the peak corresponding to the halo mass with maximum star formation efficiency to be ∼ 2 × 10¹²M_⊙, finding no evidence for evolution. It has long been known that environment has a large effect on star formation in galaxies. There are several known plausible mechanisms to remove the cool gas needed for star formation, such as strangulation, harassment and ram-pressure stripping. It is unclear which process is dominant, and over what range of stellar mass. In this thesis, I find evidence for suppression of the cross-correlation function between massive galaxies and less massive star-forming galaxies, giving a measure of how less likely a galaxy is to be star-forming in the vicinity of a more massive galaxy. I develop a formalism for modelling environmental quenching mechanisms within the HOD formalism. I find that at z ∼ 2 environment is not a significant factor in determining quenching of star-forming galaxies, and that galaxies are quenched with similar probabilities in group environments as they are globally. However, by z ∼ 0.5 galaxies are much less likely to be star forming when in a group environment than when not. This increased probability of being quenched does not appear to have significant radial dependence within the halo, supportive of the quenching being caused by the halting of fresh inflows of pristine gas, as opposed to by tidal stripping. Furthermore, by separating the massive sample into passive and star-forming, I find that this effect is further enhanced when the central galaxy is passive, a manifestation of galactic conformity. Hydrodynamical cosmological simulations, with advances in computing power over the last decade, have recently made great advances in reproducing the galaxy population and understanding the underlying physical processes behind galaxy evolution. There is extensive research in the literature comparing predicted stellar mass functions from hydrodynamical simulations to observed stellar mass functions in data. In this thesis I extend these results, comparing clustering of galaxies in mock catalogues from the hydrodynamical cosmological simulation Horizon-AGN to clustering measurements from the VIDEO observations. Clustering and HOD modelling in the Horizon-AGN mock catalogue qualitatively recreates clustering measurements from the VIDEO data, but reflects the known excess stellar mass to halo mass ratio for low mass haloes in Horizon-AGN. This reinforces the need for stronger regulation of star formation in low mass haloes in the simulation. I extend my results into the high redshift regime by studying the large-scale structure of the bright high-redshift Lyman-break galaxy (LBG) population - gaining insight into the role of environment in galaxy formation physics in the early Universe. I measure the clustering of a sample of bright (−22.7 < M_UV < −21.125) LBGs at z ∼ 6 and use a HOD model to measure their typical halo masses. I find that the clustering amplitude and corresponding HOD fits sug- gests that these sources are highly biased (b ∼ 10) objects in the densest regions of the high-redshift Universe. Coupled with the observed rapid evolution of the number density of these objects, my results suggest that the shape of high lu- minosity end of the luminosity function is related to feedback processes or the onset of dust obscuration - as opposed to a scenario where these sources are pre- dominantly rare instances of the much more numerous M_UV ∼ −19 population of galaxies caught in a particularly vigorous period of star formation. Despite investigating several variations on the model, it was not possible to simultaneously fit both the number densities and clustering measurements. I interpret this as a signal that a refinement of the model halo bias relation at high redshifts or the incorporation of quasi-linear effects may be needed for future attempts at modelling the clustering and number counts. Finally, the difference in number density between the fields (UltraVISTA has a surface density ∼ 1.8 times greater than UDS) is shown to be consistent with the cosmic variance implied by the clustering measurements. Finally I discuss future data sets that will become available in the coming years, and future approaches to modelling large-scale structure. In summary I have shown that measuring the spatial distribution of galaxies on large-scales is a vital probe of galaxy evolution and an essential tool for understanding the connection between galaxies and their dark matter haloes over cosmic time.

No description available.

NASA has funded a project called the Hunt for Observable Signatures of Terrestrial Systems (HOSTS) to survey nearby solar type stars to determine the amount of warm zodiacal dust in their habitable zones. The goal is not only to determine the luminosity distribution function but also to know which individual stars have the least amount of zodiacal dust. It is important to have this information for future missions that directly image exoplanets as this dust is the main source of astrophysical noise for them. The HOSTS project utilizes the Large Binocular Telescope Interferometer (LBTI), which consists of two 8.4-m apertures separated by a 14.4-m baseline on Mt. Graham, Arizona. The LBTI operates in a nulling mode in the mid-infrared spectral window (8-13 mu m), in which light from the two telescopes is coherently combined with a 180 degree phase shift between them, producing a dark fringe at the location of the target star. In doing so the starlight is greatly reduced, increasing the contrast, analogous to a coronagraph operating at shorter wavelengths. The LBTI is a unique instrument, having only three warm reflections before the starlight reaches cold mirrors, giving it the best photometric sensitivity of any interferometer operating in the mid-infrared. It also has a superb Adaptive Optics (AO) system giving it Strehl ratios greater than 98% at 10 mu m. In 2014 into early 2015 LBTI was undergoing commissioning. The HOSTS project team passed its Operational Readiness Review (ORR) in April 2015. The team recently published papers on the target sample, modeling of the nulled disk images, and initial results such as the detection of warm dust around eta Corvi. Recently a paper was published on the data pipeline and on-sky performance. An additional paper is in preparation on beta Leo. We will discuss the scientific and programmatic context for the LBTI project, and we will report recent progress, new results, and plans for the science verification phase that started in February 2016, and for the survey.

No description available.

The performance of existing and planned millimeter and submillimeter astronomical arrays is limited by fluctuations in the amount of atmosperic water vapor along the atenna's line of sight. Correcting the resulting phase distortion of the received signals is seen as a significant technological challenge. Measurements of the variation in the line-of-sight water vapor abundance at the level of 1 micron precipitable water vapor on a time scale of 1 second and at arbitrary antenna positions are required. This thesis describes the design of, and preliminary results obtained with, a water vapor monior operating at abundance at the level 1 micron precipitable water vapor on a time scale of 1 second and at arbitrary antenna positions are required. This thesis describes the design of, and preliminary results obtained with, a water vapor monitor operating at infrared wavelengths which shows considerable promise for this application. Improvements in, and future plans for, the second generation water vapor monitor currently under development are also discussed. / xiii, 167 leaves : ill. ; 28 cm.

The European Space Agency's Herschel Space Observatory is comprised of three cryogenically cooled instruments commissioned to explore the far infrared/submillimetre universe. The Spectral and Photometric Imaging REceiver (SPIRE) is one of Herschel's instruments and consists of a three band imaging photometer and a two band imaging spectrometer. Canada is involved in the SPIRE project through provision of instrument development hardware and software, mission flight software, and support personnel. This thesis discusses Fourier transform spectroscopy (FTS) and FTS data processing. A detailed discussion is included on FTS phase correction, with results presented from the optimization of an enhanced Forman phase correction routine developed for this work. This thesis discusses the design, verification, and use of the hardware and software provided by Dr. Naylor's group as it relates to SPIRE verification testing. Results of the photometer characterization are presented. The current status of SPIRE and its future schedule is also discussed. / xvii, 239 leaves : ill. (some col.) ; 28 cm.

The IRMA III infrared radiometer is a passive atmospheric water vapor detector designed for use with interferometric submillimeter arrays as a method of phase correction. The IRMA III instrument employs a distributed, multi-tasking software control system permitting precise fine-grained control at remote locations over a low-bandwidth network connection. IRMA's software is divided among three processors tasked with performing three primary functions: command interpretation, data collection and motor control of IRMA's Alt-Az mount. IRMA's hardware control and communication functionality is based on compact, low cost, energy efficient Rabbit 2000 microcontroller modules, selected to meet IRMA's limited space and power requirements. IRMA accepts scripts defined in a custom, high level control language as its method of control, which the operator can write or dynamically generated by a separate GUI front-end program. / xi, 193 leaves : ill. ; 28 cm.

Our group has developed a 20 μm passive atmospheric water vapour monitor. The Infrared Radiometer for Millimetre Astronomy (IRMA) has been commissioned and deployed for site testing for the Thirty Meter Telescope (TMT) and the Giant Magellan Telescope (GMT). Measuring precipitable water vapour (PWV) requires both a sophisticated atmospheric model (BTRAM) and an instrument (IRMA). Atmospheric models depend on atmospheric profiles. Most profiles are generic in nature, representing only a latitude in some cases. Site-specific atmospheric profiles are required to accurately simulate the atmosphere above any location on Earth. These profiles can be created from publicly available archives of radiosonde data, that offer nearly global coverage. Having created a site-specific profile and model, it is necessary to determine the PWV sensitivity to the input parameter uncertainties used in the model. The instrument must also be properly calibrated. In this thesis, I describe the radiometric calibration of the IRMA instrument, and the creation and analysis of site-specific atmospheric models for use with the IRMA instrument in its capacity as an atmospheric water vapour monitor for site testing. / xii, 135 leaves : ill. ; 28 cm. --

The Infrared Radiometer for Millimetre Astronomy (IRMA) is a passive atmospheric water vapour monitor developed at the University of Lethbridge. It is a compact, robust, and autonomous instrument, which is capable of being operated remotely. The latest model is based on a PC/104 running an AMD 133 MHz SC520 processor, which allows for more flexible control of the unit. The modifications and upgrades to the software required for the transition to this new platform are discussed in this thesis. In addition to software optimisation, a new calibration method has been developed as the unit has become better understood. This method has been verified through test campaigns carried out in Lethbridge and Chile. The results of these tests are included in this thesis. / xii, 141 leaves : ill. (some col.) ; 28 cm. --

Les binaires X, composées d'un objet compact (naine blanche, étoile à neutrons ou trou noir stellaire) et d'une étoile donneuse, sont des objets fascinants qui ont permis faire des découvertes majeures dans le domaine de l'astrophysique des hautes énergies. Toutefois, l'environnement immédiat de ces dernières, à l'échelle de $\sim$ 100--10,000 unités astronomiques, n'est pour sa part que très peu compris et exploré. Dans ce mémoire, on s'intéresse à la présence de compagnons, autant de masse planétaire que stellaire, dans lesdits environnements des binaires X. Pour ce faire, on a fait appel à des techniques observationnelles qui sont normalement utilisées pour la recherche d'exoplanètes jeunes, chaudes et en orbite autour d'étoiles situées à quelques parsecs de la Terre : il s'agit de l'imagerie directe ou plus précisément de l'imagerie à haut contraste. Ainsi, pour la toute première fois, on a appliqué ces méthodes sur un échantillon de binaires X avec l'instrument proche infrarouge NIRC2 de l'Observatoire W. M. Keck, avec l'aide d'un système d'optique adaptative et d'un coronographe. Ici, on a présenté les premières images à haut contraste de 14 binaires X. Le but était de détecter des sources lumineuses dans les images et de calculer leur flux et leur position avec des méthodes d'optimisation. Ensuite, il s'agissait de définir via diverses analyses si celles-ci sont cohérentes avec des compagnons liés par la gravité à la binaire X, ou plutôt avec des étoiles de fond. Ces travaux se veulent donc une introduction à un nouveau sous-domaine de l'astrophysique qui tente de relier l'exoplanétologie et l'astrophysique des hautes énergies. / X-ray binaries, consisting of a compact object (white dwarf, neutron star or stellar-mass black hole) and a donor star, are fascinating objects that have allowed major breakthroughs in the field of high-energy astrophysics. However, their immediate environments, on the scale of $\sim$ 100--10,000 astronomical units, are still poorly understood. In this Master's thesis, we investigated the presence of companions, ranging from planetary to stellar masses, in the environments of X-ray binaries. In order to do so, we used observational techniques that are normally used for the search of young, hot and distant exoplanets orbiting stars located at a few parsecs from the Earth: direct imaging or more precisely high-contrast imaging. Thus, for the very first time, we applied these techniques on a sample of X-ray binaries with the near-infrared instrument NIRC2 of the W. M. Keck Observatory, with the help of an adaptive optics system and a coronagraph. Here, we present the first high-contrast images for 14 X-ray binaries. The goal was to detect point sources in the images and to calculate their flux and position with optimization methods. Afterward, we determined via a variety of analyses if these were consistent with companions gravitationally bounded to the X-ray binary, or rather with background stars. This work acts as an introduction, albeit exploratory, to a new subfield of astrophysics that attempts to link exoplanetology and high-energy astrophysics.