Many astronomical observations, including rotational curve measurements of stars and the analysis of the cosmic microwave background, suggest the existence of an invisible matter density content in the Universe, commonly called Dark Matter (DM). Possibly, DM could be of particle nature, where Weakly Interacting Massive Particles (WIMPs) could be a viable DM candidate. The cubic-kilometer sized IceCube neutrino observatory located at the Earth’s South Pole can search indirectly for the existence of DM by detecting neutrino signals from WIMP self-annihilation in the Galactic center (GC) and the Galactic halo (GH). Two main physics analyses were developed and conducted to search indirectly for WIMP self-annihilation in the Milky Way’s GC and GH. Signal hypotheses for different WIMP annihilation channels, WIMP masses and DM halo profiles were tested. The results of both analyses were compatible with the background-only hypothesis for all tested signal hypotheses. Thus, upper limits at the 90% confidence level (C.L.) on the thermally averaged DM self-annihilation cross-section, &lt;σΑv&gt;, were set. Dedicated atmospheric muon veto techniques have been developed for the GC search making such an IceCube analysis possible for the first time. The GC analysis utilized data from 319.7 days of live-time of the IceCube detector running in its 79-string configuration during 2010 and 2011, whereas the GH analysis utilized pre-existing data samples developed for point-like neutrino sources with a live-time of 1701.9 days between 2008 and 2013. The most stringent upper limits on &lt;σΑv&gt; were obtained for WIMP annihilation directly into a pair of neutrinos assuming a Navarro-Frenk-White (NFW) DM halo profile. Conducting the GC and GH analyses for this annihilation channel an upper limit on &lt;σΑv&gt; as low as 4.0 · 10-24 cm3 s-1 and 4.5 · 10-24 cm3 s-1 is set for a 65 GeV and 500 GeV massive WIMP, respectively. These galactic indirect neutrino searches for DM are complementary to the indirect gamma-ray DM searches usually performed on extra-galactic targets like spheroidal dwarf galaxies. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p>

The Canadian astrophysics program rapidly developed between 1903 and 1914, leading to the wartime construction of what was hoped to be the world’s largest research telescope. The institution opened in Victoria British Columbia in 1918 with fanfare. Throughout the 1920s, the new Dominion Astrophysical Observatory (DAO) contributed to discoveries on the frontiers of astrophysics, while educating residents of Victoria about astronomy. In a history often overshadowed by the advent of cosmology in the 1920s, the discoveries of Victoria’s astronomers produced lasting insight into the size and scale of our own galaxy. Accordingly, historians of astronomy have probed the scientific accomplishments of Canadian astronomers, devoting relatively little attention to the regional importance of these scientific facilities. The Victoria observatory itself developed into a widely visited tourism destination as staff astronomers regularly engaged in public education initiatives. This study utilizes newspaper sources, scientific papers, and contemporary publications in assessing the cultural relationship between the DAO, Victorians, and Canadians, while examining the significance of the scientific research conducted with the world’s second largest telescope. In doing so it engages themes of public interest in the achievements of the institution, and Victoria’s civic identity as an emerging tourism destination. / Graduate / 0334 / 0585 / danielgposey@gmail.com

Le principal objectif de ce travail est d'étudier les propriétés multi-longueurs d'onde d'un échantillon de galaxies pour mieux comprendre leur formation et leur évolution. J'ai utilisé les observations du Herschel en complément de données multi-longueurs d'onde dans le champ. J'ai réalisé une extraction des sources ponctuelles. Des catalogues de sources ont été générés en utilisant la méthode de l'ajustement de PSF. J'ai utilisé des catalogues SPIRE pour rechercher des candidats de galaxies SMG subissant les effets d'une lentille gravitationnelle. J'ai identifié 6 sources dans la liste principale et 55 sources dans une liste supplémentaire. En utilisant des ajustements de SEDs, j'ai ensuite estimé la distribution de redshifts de ces sources, et avons ensuite mené une analyse pour contraindre les propriétés des poussières. J'ai trouvé qu'il est très probable que ces sources soient des systèmes lensés. Mentionnons que parmi nos candidates, j'ai découvert une source rouge unique dont la SED en infrarouge lointain croît et qui semble être une galaxie sub-mm (SMG) fortement lensée à haut redshift. Ce genre de sources est rare et la plupart sont découvertes par hasard. J'ai soumis des propositions photométriques et spectroscopiques pour mesurer le redshift de cette source, en utilisant des observations continues avec IRAM-Nika2, NOEMA et SMA et des observations spectroscopiques avec le télescope de 30m de l'IRAM, NOEMA et GEMINI-nord. Les observations ont permis de mesurer le redshift de la lentille et de la galaxie lensée. Une autre observation sera exécutée avant la fin de l'année. Les résultats sont très prometteurs mais j'ai encore besoin de plus de données. / The main aim of this work is to study the multi-wavelength properties of a sample of galaxies to better understand their formation and evolution. I used the new observations from GALEX and \textit{Herschel} in combination with multi-wavelength data available in the field. I made point source catalogs extracted from the observations of GALEX, and \textit{Herschel} SPIRE and PACS bands using the method of the PSF fitting. Then I used Monte Carlo simulations to quantify the quality of the photometry process and the catalogs.Then I used SPIRE catalogs to search for candidate gravitationally lensed SMGs at high redshift. I identified 6 sources sources in a main list, and 55 sources in a supplementary list. Using SED fitting, performed with CIGALE code, I estimated the redshift distributions of these sources, and constrained their dust properties. I found that, it is very likely that we have gravitationally lensing systems. It should be mentioned that within our candidates we have discovered a unique red source with a rising Far-IR SED, which appears to be a strongly lensed submillimeter galaxies at z~5.2. This kind of sources are quite rare on the sky and are serendipitously discovered. I proposed some followup photometric and spectroscopy observation to measure the redshift of this sources, using for instance continuum observations with IRAM-Nika2, NOEMA, and SMA, and spectroscopic observation with IRAM 30m telescope, NOEMA, and GEMINI-North. The GEMINI-North observations succeeded in measuring the redshifts of the lens and of the lensed galaxy. One more will be executed at the end of this year. The results is quite promising, but more data are needed.

The complex and diverse populations of galaxies observed today form hierarchically through past galactic mergers. Interactions between galaxies of similar masses will drastically alter the morphology, chemical composition, star-formation activity, and central black-hole accretion of their constituents. Though we can see the components and byproducts of galaxy mergers, these events endure over a timescale of hundreds of millions of years. Thus to understand the merging process from observations, astronomers are reliant on large spectroscopic surveys which will contain galaxy mergers at various stages of interaction, and those which have just experienced coalescence. Until recently, such surveys were limited to the global properties of each galaxy, constraining the global changes in chemical composition and star-formation activity, but overlooking how such changes vary across a galaxy. The advent of Integral Field Unit (IFU) spectroscopy surveys provides spatially resolved spectroscopic properties for thousands of galaxies for the first time. This thesis presents analysis of galaxy mergers from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) IFU spectroscopy survey. Enhancements and deficits in star-formation rate and metallicity, as a result of the interaction, are determined for each spatial pixel containing a spectrum (spaxel) based on well established relationships with stellar mass density. These offsets are then compressed into radial profiles to quantify how the effects of an interaction vary as a function of radius. A sample of 36 post-mergers are, on average, enhanced out to ~2 effective radii, though individual galaxies can be enhanced or suppressed in the outskirts depending on the global star-formation rate of the galaxy. The metallicity is uniformly suppressed in post-merger galaxies, in concordance with the global SFR enhancement. A sample of galaxy pairs is identified with cuts in the projected separation, the line of sight velocity difference, and the mass ratio of the interaction. I develop a method to deblend close galaxy pairs that are on the same IFU observation, and remove contribution from the companion galaxy in the radial profile. Radial profiles of SFR and metallicity offsets for the pairs sample, binned by projected separation, confirm that central enhancements in SFR increase as separation decreases. Behaviour in the outskirts is more varied, and does not appear to correlate with the projected separation or the mass ratio of the interaction. Metallicity offsets display a similar issue, showing no clear correlation with separation or mass ratio. Such ambiguity implies that multiple characteristics of the interaction and its components are required to predict the spatial changes in a galaxy merger. I propose projects that could shed light on these ambiguities. The most recent release of MaNGA will double the sample size of mergers, possibly homogenizing projected separation and mass ratio bins that may be dominated by a particular population. An analysis of interacting galaxies that do not have mass ratio measurements, but very small projected separations and highly disturbed morphologies, could provide understanding of the transition between the very end of an interaction and the state of the galaxy post-coalescence. I also propose a more complex analysis of the asymmetry of IFU spectroscopy data products, which until now have been simplified with radial profiles. Lastly, I emphasize the importance of follow up studies of the resolved molecular gas properties of merging galaxies to discern whether gas reservoir, depletion time, or both are driving the change in star-formation rate. / Graduate

O-LiFE est un observatoire de l’environnement dédié à l’étude des ressources et de la biodiversité dans la zone critique à la vie, focalisé sur la méditerranée. C’est aussi une structure à l’interface entre la recherche fondamentale et les porteurs d’enjeux. Cette plateforme initiée en collaboration entre des équipes libanaises et françaises se focalise d’abord sur l’observation systémique du milieu naturel, autour des thématiques de l’eau, la biodiversité et la gestion de l’environnement. Le fondement de l’observatoire est la mise en oeuvre d’une approche transdisciplinaire du défi du changement global. Structurer, partager, pérenniser et valoriser les données environnementales constitue un objectif prioritaire pour permettre à une large communauté de converger vers une approche réellement systémique et transdisciplinaire des enjeux environnementaux en Méditerranée. La construction d’un système d’information permettant cette mise en relation complète des données est donc prioritaire. Cependant cette mise en oeuvre est rendu complexe par plusieurs défis à relever pour répondre aux utilisateurs finaux et producteurs de données qui ne partagent pas les mêmes besoins, et pour tenir compte de l’hétérogénéité naturelle des données.Dans cette thèse, nous détaillons par conséquent les réflexions et travaux menés pour la mise en place de l’architecture du SI de l’observatoire. Le travail a été initié par une enquête permettant de mieux connaître les sources de données existantes. Nous avons ensuite proposé d’utiliser les environnements de gestion de données d’observations basés sur des ontologies partagées et les recommandations des consortiums reconnus (OGC). Des extensions sont proposées pour permettre la prise en compte de points de vue distincts sur les données via des multi-mapping. Cette extension permet un découplage entre la vision initiale du producteur de données et les multiples utilisations possibles des données à l’aide de croisement avec d’autres sources de données et/ou d’autres points de vue.Nous avons enfin appliqué la méthodologie sur les données O-LiFE et avons pu extraire des croisements de données inter-bases (entre deux sources de données distinctes) et intra-bases (en juxtaposant des points de vue distincts sur une même source de données). Ce travail est une démonstration du rôle fondamental des outils du SI et des observatoires dans le rapprochement indispensable des communautés scientifiques autant que des porteurs d’enjeux pour la résolution des grands défis sociétaux environnementaux, notamment en Méditerranéen. / O-LiFE is an environmental observatory dedicated to the study of resources and biodiversity in the critical area of life, focused on the Mediterranean. It is also a structure at the interface between basic research and the holders of issues. This platform initiated in collaboration between Lebanese and French teams focuses first on systemic observation of the natural environment around the themes of water, biodiversity and environmental management. The foundation of the observatory is the implementation of a transdisciplinary approach to the challenge of global change.Organize, share, sustain and enhance environmental data is a priority objective to enable the wider community to converge towards a truly systemic and transdisciplinary approach to environmental issues in the Mediterranean. The construction of an information system allowing complete connection of data is therefore a priority. However, this implementation is complicated by a number of challenges to meet the end users and data producers expectations who do not share the same needs, and to take into account thenatural heterogeneity of data.In this PhD, we detail brainstorming and work needed for the development of the architecture of the information system of the observatory. The work was initiated by a survey to better understand theexisting sources of data. We then proposed to use observational data management environments based on shared ontologies and the recommendations of recognized consortia (OGC). Extensions are proposed to enable the inclusion of different perspectives on data through multi-mapping. This extension allows a decouplingbetween the original vision of the data producer and the many possible uses of the data with crossbreeding with other data sources and / or other views.We then applied the methodology on the O-LiFE data and were able to extract inter-data analysis (between two distinct data sources) and intra-bases analysis (by juxtaposing different points of view on the same data source). This work is a demonstration of the fundamental role of IS tools and observatories in the essential gathering of the scientific communities as much as stakeholders to resolve major environmental challenges facing society, particularly in Mediterranean.

Em uma investigação das práticas torcedoras presentes em um estádio de futebol, esta pesquisa aborda a formação de memórias como elemento produtor de sujeitos. Estes torcedores mantêm vínculos muito particulares com o futebol e com uma instituição inserida no modelo de futebol de espetáculo, considerando-se a relação torcedor-torcedor e torcedor-clube. Com especial atenção aos rituais que acontecem antes, durante e depois dos jogos, o estudo traz a tona quais os dispositivos de memória são construídos a partir desses rituais. Com o auxílio da participação observante, é identificado como os torcedores do Grêmio Esportivo Brasil se relacionam e se manifestam no estádio do clube. Diante das singularidades da memória coletiva produzidas pelos torcedores – como em um jogo no ano 1946 – foram se construindo elementos que passaram a nomear a torcida através da figura do “índio xavante”. A violência e fidelidade que estão contidas nesse símbolo são produções que rondam os torcedores xavantes e com o tempo se alteram e são acessados por meio das práticas dos torcedores. Partindo da memória como elemento norteador do processo investigativo e analítico, o investimento nesta pesquisa se faz por meio de práticas sociais que toma o estádio de futebol e as práticas educativas relacionadas ao torcer como elemento de análise, tendo como foco as interações entre o fazer ciência e a produção dos sujeitos. Além disso, visa compreender como os discursos e as práticas atuam na produção de "verdades" e dos sujeitos – no caso desta pesquisa, os torcedores xavantes –, engendrados através das práticas da memória. Enfrentada pelo único limite que é a morte dos indivíduos, a memória social dos torcedores xavantes ocupa um espaço privilegiado para se pensar suas práticas torcedoras atuais. Após a criação de vínculos com o clube, realizadas por práticas cotidianas que se defrontam os sujeitos no estádio, o pertencimento clubístico parece demarcar fortemente o que se esquece e o que não se quer esquecer. Através da ligação entre torcedores e clube, encontrada em uma rede sociabilidade que é constituída dentro do Grêmio Esportivo Brasil, os torcedores se reconhecem como sujeitos torcedores deste clube. / In an investigation of fans practices in a football stadium, this research approaches the formation of memories as a subject’s producer. These fans are closed and keep special link with football and an institution in the soccer spectacle model, considering the relationship between fan-fan and fan-club. With special attention to the rituals that occur before, during and after the games, the study brings out which mechanisms of the memory are constructed from these rituals. With the help of observatory participation, is identified how the fans of Grêmio Esportivo Brasil are related and manifests themselves in the football stadium. The collective memory peculiarities produced by the fans - as in a game in 1946 - were built elements that configure the Xavante Indians simbols. Violence and loyalty that are contained in this symbol Xavante are fans productions which changes by time and are accessed through the practices of the fans. Starting from the memory as a guiding element of investigative and analytical process, the investment in this research is done through social practices that take the football stadium and educational practices related to support as analysis element, focusing on the interaction between doing science and production of subjects. Moreover, it aims to understand how discourses and practices operate in the production of “truths” and subjects – in the case of this research, xavante’s fan – engendered through memory’s practices. Faced by the only limit that is the death of individuals, the social memory of Xavante’s fans occupies a privileged space to think about their current fans practices. After the establishment of links with the club, made by everyday practices faced by subjects in the stadium, belonging to a club seems to strongly demarcate what is forgotten and what you do not want to forget. Through the connection between fans and club, found in a sociability’s network that is formed within Grêmio Esportivo Brasil, the fans recognizes themselves as subjects fans of this club.

abstract: The development of new Ultra-Violet/Visible/IR range (UV/Vis/IR) astronomical instrumentation that use novel approaches for imaging and increase the accessibility of observing time for more research groups is essential for rapid innovation within the community. Unique focal planes that are rapid-prototyped, low cost, and provide high resolution are key. In this dissertation the emergent designs of three unique focal planes are discussed. These focal planes were each designed for a different astronomical platform: suborbital balloon, suborbital rocket, and ground-based observatory. The balloon-based payload is a hexapod-actuated focal plane that uses tip-tilt motion to increase angular resolution through the removal of jitter – known as the HExapod Resolution-Enhancement SYstem (HERESY), the suborbital rocket imaging payload is a Jet Propulsion Laboratory (JPL) delta-doped charge-coupled device (CCD) packaged to survive the rigors of launch and image far-ultra-violet (FUV) spectra, and the ground-based observatory payload is a star centroid tracking modification to the balloon version of HERESY for the tip-tilt correction of atmospheric turbulence. The design, construction, verification, and validation of each focal plane payload is discussed in detail. For HERESY’s balloon implementation, pointing error data from the Stratospheric Terahertz Observatory (STO) Antarctic balloon mission was used to form an experimental lab test setup to demonstrate the hexapod can eliminate jitter in flight-like conditions. For the suborbital rocket focal plane, a harsh set of unit-level tests to ensure the payload could survive launch and space conditions, as well as the characterization and optimization of the JPL detector, are detailed. Finally, a modification of co-mounting a fast-read detector to the HERESY focal plane, for use on ground-based observatories, intended to reduce atmospherically induced tip-tilt error through the centroid tracking of bright natural guidestars, is described. / Dissertation/Thesis / Doctoral Dissertation Exploration Systems Design 2019

This document presents a study of astronomical observing conditions of Hard Labor Creek Observatory. Analysis of factors such as sky brightness, astonomical seeing, and patterns in the level of cloudiness at the site are presented. Characteristics of the observatory's Apogee Alta U230 camera are also measured and calculated. These characteristics include loss of linearity in the CCD's response to light, read noise, gain, dark current, and stability in the camera's bias levels. The camera is also used in conjunction with the 20-inch RC Optics telescope to determine the system's pixel scale and a set of limiting magnitudes for the Johnson-Cousins photometric filters that are used with the camera. Observations of a transit of known transiting exoplanet Qatar-2 b as well as observations of the open cluster Messier 29 are also performed to demonstrate the ability of the equipment to perform precise photometric observations.

A one-kilometer-diameter carbonate/hydrate mound in Mississippi Canyon Block 118 has been chosen to be the site of a multi-sensor, multi-discipline sea-floor observatory. Several surveys have been carried out in preparation for installing the observatory. The resulting data set permits discussing the mound’s structure in some detail. Samples from the water column and intact hydrate outcrops show gas associated with the mound to be thermogenic. Lithologic and bio-geochemical studies have been done on sediment samples from gravity and box cores. Pore-fluid analyses carried out on these cores reveal that microbial sulfate reduction, anaerobic methane oxidation, and methanogenesis are important processes in the upper sediment. These microbial processes control the diffusive flux of methane into the overlying water column. The activity of microbes is also focused within patches near active vents. This is primarily dependent upon an active flux of hydrocarbon-rich fluids. The geochemical evidence suggests that the fluid flux waxes and wanes over time and that the microbial activity is sensitive to such change. Swath bathymetry by AUV combined with sea-floor video provides sub-meter resolution of features on the surface of the mound. Seismic reflection profiling with source-signature processing resolves layer thicknesses within the upper 200-300m of sediment to about a meter. Exploration-scale 3-D seismic imaging shows that a network of faults connects the mound to a salt diapir a few hundred meters below. Analyses of gases from fluid vents and hydrate outcrops imply that the faults act as migration conduits for hydrocarbons from a deep, hot reservoir. Source-signature-processed seismic traces provide normal-incidence reflection coefficients at 30,000 locations over the mound. Picking reflection horizons at each location allows a 3-D model of the mound’s interior to be constructed. This model provides a basis for understanding the movement of fluids within the mound.

Pulsar wind nebulae (PWNe), nebulae harbouring a rotation-powered neutron star that was born in a supernova, provide opportunities to study highly relativistic pulsar winds and their interaction with the surrounding medium. Particularly interesting are PWNe that do not show any sign of the expected surrounding SNR shell and were thought to be born in subenergetic explosions or with unusual progenitors. The detection of a shell around one such PWN suggested that shells are indeed produced but may be faint due to unseen shocked ejecta, a low density environment, and/or a young age that has not yet allowed the shell to brighten and become visible. Here, by using observational X-ray data from modern telescopes with excellent spatial and energy resolution (Chandra and XMM-Newton), we target PWNe that do not have prominent SNR shells, and are known to be in varied environments, to further explore the characteristics of this growing, but poorly explored, class of PWNe. By combining imaging and spectroscopic results, we study the morphology of the PWNe, search for thermal emission from shock-heated material, investigate the energetics of the nebulae, and search for candidates for the neutron stars powering the nebulae. We find that while the faint shell surrounding G21.5–0.9 can be explained as a young PWN evolving in a low density medium, CTB 87 (G74.9+1.2) appears to be in an advanced stage of evolution, and G63.7+1.1 appears to be both in an advanced stage of evolution and in a dense environment. By performing spatially resolved spectroscopy, we have shown how the spectral characteristics vary across the PWNe, and note that more data will place better constraints on possible thermal emission in these remnants. The imaging portion of these studies has revealed intriguing large-scale morphologies for CTB 87 and G63.7+1.1, as well as a torus-jet structure in CTB 87 and neutron star candidates in both CTB 87 and G63.7+1.1. We conclude that both CTB 87 and G63.7+1.1 are likely interacting with the supernova remnant reverse shock, and CTB 87 may be additionally influenced by the motion of its neutron star.