This thesis aimed to create a messaging protocol for OpenSpace to interoperate with other astronomy software. The goal was to create a messaging standard that was not language-dependent and could be implemented by any astronomy software. To establish an asynchronous communication between OpenSpace and connected software, the Transmission Control Protocol (TCP), threading, and Peer-To-Peer (P2P) were the techniques mainly used. TCP was used to achieve reliable communication between software connected to the network. The enabling of two-way communication was solved by threading. P2P was used as a network communication architecture to share resources between the connected software. By using Unicode characters expressed through UTF-8, the Unicode Standard was used to encode messages sent. The messages are structured by combinations of different sizes of bytes and are sent and received as binary strings. All messages contain a header and the data being sent. Different message types were created to specify which type of data is sent. The protocol works primarily between OpenSpace and Glue but is not limited to these software. The implementation serves as the basis of the messaging protocol for OpenSpace, where Glue represents future software integrations.

<p>The field of radio astronomy continues to provide fundamental contributions to the understanding of the evolution, and inner workings of, our universe. It has done so from its humble beginnings, where single antennas and receivers were used for observation, to today's focal plane arrays and interferometers. The number of receiving elements (pixels) in these instruments is quickly growing, currently approaching one hundred. For the instruments of tomorrow, the number of receiving elements will be in the thousands. Such instruments will enable researchers to peer deeper into the fabric of our universe and do so at faster survey speeds. They will provide enormous capability, both for unraveling today's mysteries as well as for the discovery of new phenomena.</p> <p>Among other challenges, producing the large numbers of low-noise amplifiers required for these instruments will be no easy task. The work described in this thesis advances the state of the art in three critical areas, technological advancements necessary for the future design and manufacturing of thousands of low-noise amplifiers. These areas being: the automated, cryogenic, probing of $\diameter100$ mm indium phosphide wafers; a system for measuring the noise parameters of devices at cryogenic temperatures; and the development of low-noise, silicon germanium amplifiers for terahertz mixer receivers. The four chapters that comprise the body of this work detail the background, design, assembly, and testing involved in these contributions. Also included is a brief survey of noise parameters, the knowledge of which is fundamental to the design of low-noise amplifiers and the optimization of the system noise temperature for large, dense, interferometers.</p>

The search to find answers to the deepest questions we have about the Universe has fueled the collection of data for ever larger volumes of our cosmos. The field of supernova cosmology, for example, is seeing continuous development with upcoming surveys set to produce a vast amount of data that will require new statistical inference and machine learning techniques for processing and analysis. Distinguishing between real objects and artefacts is one of the first steps in any transient science pipeline and, currently, is still carried out by humans - often leading to hand scanners having to sort hundreds or thousands of images per night. This is a time-consuming activity introducing human biases that are extremely hard to characterise. To succeed in the objectives of future transient surveys, the successful substitution of human hand scanners with machine learning techniques for the purpose of this artefact-transient classification therefore represents a vital frontier. In this thesis we test various machine learning algorithms and show that many of them can match the human hand scanner performance in classifying transient difference g, r and i-band imaging data from the SDSS-II SN Survey into real objects and artefacts. Using principal component analysis and linear discriminant analysis, we construct a grand total of 56 feature sets with which to train, optimise and test a Minimum Error Classifier (MEC), a naive Bayes classifier, a k-Nearest Neighbours (kNN) algorithm, a Support Vector Machine (SVM) and the SkyNet artificial neural network.

Syftet med denna konsumtionsuppsats var att genom en systematisk litteraturstudie, undersöka vad forskningen har att säga om problematik och lösningar med avseende på undervisning inom astronomi i skolan, med inriktning på årskurs 4–6. Vi använde oss av såväl databassökningar som manuella sökningar. Vi utgick från två frågeställningar:  1) Vilka problem kan uppstå när man undervisar inom astronomi?  2) Hur löser man dessa problem? Resultaten visade att ett stort hinder vid undervisningen inom astronomi beror på missuppfattningar och bristande kunskaper, både hos elever och lärare. Därför är det viktigt att kunna synliggöra och hantera missuppfattningar, genom olika metoder och strategier till exempel genom att gå från mindre delar till helhet. Detta är enligt forskningen något vi som lärare bör ha i åtanke när vi planerar vår undervisning i astronomi.

A presente pesquisa analisou materiais e propostas didáticas sobre o tema da astronomia cultural, tendo em vista sua inserção no ensino de tópicos de Física e Ciências na educação básica. A astronomia cultural pode ser tomada como o estudo das relações entre os saberes produzidos sobre o céu e as dinâmicas socioculturais de um dado grupo. A existência de uma grande multiplicidade de culturas indica a possibilidade de inúmeras formas de se relacionar com os elementos celestes. Tal diversidade pouco ou raramente é explorada, sendo um dos objetos desta pesquisa evidenciar que as discussões desta temática podem ser potencialmente interessantes para trabalhar em sala de aula a questão do respeito à diversidade cultural, apresentando aos estudantes outras lógicas de pensamento, distintas das referências da cultura ocidental. Foram realizadas revisões bibliográficas a fim de construir um panorama da produção dos pesquisadores da área de ensino de ciências junto aos temas do multiculturalismo e da astronomia cultural. Este procedimento favoreceu o contato com materiais e propostas didáticas que foram selecionadas para comporem o conjunto de dados a ser trabalhado. Com base na metodologia da análise de conteúdo, doze documentos que abordaram a astronomia cultural de maneira articulada ao contexto da sala de aula foram analisados, investigando-se três dimensões de análise. Os questionamentos realizados se relacionam aos seguintes aspectos: principais temas abordados pelos materiais; tipos de perspectivas voltadas ao multiculturalismo e à noção de cultura; o papel de medidas legislativas, a exemplo da Lei Federal nº 11.645/08, no aumento da produção de materiais abordando a astronomia cultural. Dentre os resultados da análise, verificou-se que os temas com maior frequência estão relacionados a narrativas sobre o funcionamento do universo e aos asterismos (ou constelações) de algumas etnias indígenas, sendo pouco recorrente o trabalho aprofundado com variadas estruturas de pensamento ou outras visões de mundo distintas da cultura ocidental. Sobre a abordagem ao multiculturalismo, houve uma polarização entre um viés diferencialista, que valoriza as diferenças particulares dos grupos, e uma postura intercultural, com ênfase no diálogo. Almeja-se que o trabalho possa contribuir para evidenciar algumas das potencialidades do ensino de astronomia cultural na educação básica, ao inserir discussões voltadas a diversidade cultural a fim de formar indivíduos que estejam menos centrados nas práticas de seu próprio grupo e mais abertos ao intercâmbio entre culturas e saberes distintos. / The present research examined materials and didactic proposals on the topic of cultural astronomy, with a view to their inclusion in the teaching of physics and science topics in basic education. Cultural astronomy can be taken as the study of the relationship between knowledge produced about sky and socio-cultural dynamics of a given group. The existence of a great variety of cultures indicates the possibility of numerous ways to relate to the elements of the sky. Such little diversity or is rarely explored, being one of the objects of this research show that discussions of this theme can be potentially interesting to work in the classroom the issue of respect for cultural diversity, showing other students thought logic, other than the reference of Western culture. Bibliographical reviews were carried out in order to build a panorama of the production of the researchers of science teaching with the themes of multiculturalism and cultural astronomy. This procedure favored contact with didactic materials and proposals that have been selected to compose the set of data to be worked. Based on content analysis methodology, twelve documents that addressed cultural Astronomy of articulated way to the context of the classroom were analyzed investigating three dimensions of analysis. The questions made relate to the following aspects: main themes addressed by the materials; types of prospects aimed at multiculturalism and the concept of culture; the role of legislative measures, such as the Federal Law no. 11,645, increasing production of materials addressing the cultural astronomy. One of the results of the analysis, it was found that the subjects most often are related to narratives about the workings of the universe and the asterisms (or constellations) of some indigenous ethnic groups, being little in-depth work with recurrent varied structures of thoughts or other worldviews. On the approach to multiculturalism, there\'s been a polarization between a differentialist bias, that values the differences of private groups, and an intercultural attitude. Aims that the work will help to highlight some of the potential of cultural astronomy education in basic education, to enter discussions to cultural diversity in order to train individuals who are less focused on the practices of their own group and more open to the exchange between cultures and knowledge.

A presente pesquisa analisou materiais e propostas didáticas sobre o tema da astronomia cultural, tendo em vista sua inserção no ensino de tópicos de Física e Ciências na educação básica. A astronomia cultural pode ser tomada como o estudo das relações entre os saberes produzidos sobre o céu e as dinâmicas socioculturais de um dado grupo. A existência de uma grande multiplicidade de culturas indica a possibilidade de inúmeras formas de se relacionar com os elementos celestes. Tal diversidade pouco ou raramente é explorada, sendo um dos objetos desta pesquisa evidenciar que as discussões desta temática podem ser potencialmente interessantes para trabalhar em sala de aula a questão do respeito à diversidade cultural, apresentando aos estudantes outras lógicas de pensamento, distintas das referências da cultura ocidental. Foram realizadas revisões bibliográficas a fim de construir um panorama da produção dos pesquisadores da área de ensino de ciências junto aos temas do multiculturalismo e da astronomia cultural. Este procedimento favoreceu o contato com materiais e propostas didáticas que foram selecionadas para comporem o conjunto de dados a ser trabalhado. Com base na metodologia da análise de conteúdo, doze documentos que abordaram a astronomia cultural de maneira articulada ao contexto da sala de aula foram analisados, investigando-se três dimensões de análise. Os questionamentos realizados se relacionam aos seguintes aspectos: principais temas abordados pelos materiais; tipos de perspectivas voltadas ao multiculturalismo e à noção de cultura; o papel de medidas legislativas, a exemplo da Lei Federal nº 11.645/08, no aumento da produção de materiais abordando a astronomia cultural. Dentre os resultados da análise, verificou-se que os temas com maior frequência estão relacionados a narrativas sobre o funcionamento do universo e aos asterismos (ou constelações) de algumas etnias indígenas, sendo pouco recorrente o trabalho aprofundado com variadas estruturas de pensamento ou outras visões de mundo distintas da cultura ocidental. Sobre a abordagem ao multiculturalismo, houve uma polarização entre um viés diferencialista, que valoriza as diferenças particulares dos grupos, e uma postura intercultural, com ênfase no diálogo. Almeja-se que o trabalho possa contribuir para evidenciar algumas das potencialidades do ensino de astronomia cultural na educação básica, ao inserir discussões voltadas a diversidade cultural a fim de formar indivíduos que estejam menos centrados nas práticas de seu próprio grupo e mais abertos ao intercâmbio entre culturas e saberes distintos. / The present research examined materials and didactic proposals on the topic of cultural astronomy, with a view to their inclusion in the teaching of physics and science topics in basic education. Cultural astronomy can be taken as the study of the relationship between knowledge produced about sky and socio-cultural dynamics of a given group. The existence of a great variety of cultures indicates the possibility of numerous ways to relate to the elements of the sky. Such little diversity or is rarely explored, being one of the objects of this research show that discussions of this theme can be potentially interesting to work in the classroom the issue of respect for cultural diversity, showing other students thought logic, other than the reference of Western culture. Bibliographical reviews were carried out in order to build a panorama of the production of the researchers of science teaching with the themes of multiculturalism and cultural astronomy. This procedure favored contact with didactic materials and proposals that have been selected to compose the set of data to be worked. Based on content analysis methodology, twelve documents that addressed cultural Astronomy of articulated way to the context of the classroom were analyzed investigating three dimensions of analysis. The questions made relate to the following aspects: main themes addressed by the materials; types of prospects aimed at multiculturalism and the concept of culture; the role of legislative measures, such as the Federal Law no. 11,645, increasing production of materials addressing the cultural astronomy. One of the results of the analysis, it was found that the subjects most often are related to narratives about the workings of the universe and the asterisms (or constellations) of some indigenous ethnic groups, being little in-depth work with recurrent varied structures of thoughts or other worldviews. On the approach to multiculturalism, there\'s been a polarization between a differentialist bias, that values the differences of private groups, and an intercultural attitude. Aims that the work will help to highlight some of the potential of cultural astronomy education in basic education, to enter discussions to cultural diversity in order to train individuals who are less focused on the practices of their own group and more open to the exchange between cultures and knowledge.

Using new wide-area galaxy redshift surveys, we explore the evolutionof the most massive galaxies and the most luminous quasars in the universe over much of cosmic history. Quasars and massive red galaxies both areextremes; the most luminous high redshift quasars likely play a key role in shaping their nearby environment and the universe as a whole. The mostmassive galaxies represent the end points of galaxy evolution and containa fossil record of the galaxy evolution process.Using the AGES redshift survey completed with the MMT and the Hectospecmulti-object spectrograph as well as new $z$-band observations of the NOAO Deep Wide-Field Survey Bootes field, we report the discovery of threenew quasars at z>5. We explore new mid-infrared selection in light of thesethree new quasars and place constraints on the slope of the high-redshiftquasar luminosity function.At lower redshift (0.1<z<0.4) we measure the scatter in red galaxy colorsaround the optical red-sequence using imaging and spectroscopy from theSloan Digital Sky Survey. With our sample of nearly 20,000 massiveearly-type galaxies (L>2.2L*), we find that the scatter around the color-magnitude relation is quite small in colors studied.Each of three model star formation histories can reproduce the scatter we measure, none of the models producecolor distributions matching those observed.We measure the evolution of the LRG luminosity function in the redshift range 0.1<z<0.9. We find that theLRG population has evolved little beyond the passive fading of its stellar populations since z~0.9. The most massive (L>3L*)red galaxies have grown by less than 50% (at 99% confidence) since z=0.9 in stark contrast to the factor of 2 to 4 growth observed in the L* red galaxy population over the same epoch.Finally, we introduce the PRIsm MUlti-object Survey (PRIMUS), a new redshiftsurvey aimed at collecting ~300,000 galaxy spectra over 10 sq. deg toz~1. We summarize the current status of PRIMUS observations and datareductions and present several survey statistics. PRIMUS is the largestexisting redshift survey at intermediate redshift and holds the largestsample of redshifts for Spitzer and X-ray detected objects.

In this thesis I present an in-depth study of the distribution of various neutral species in Titan’s upper atmosphere, at altitudes between 950 and 1,500 km for abundant species (N₂, CH₄ as well as their isotopes) and between 950 and 1,200 km for most minor species. However, the study of the H2 distribution on Titan is extended to an altitude as high as 6,000 km in the exosphere. The analysis is based on a large sample of Cassini/INMS (Ion Neutral Mass Spectrometer) measurements in the CSN (Closed Source Neutral) mode, obtained during 15 close flybys of Titan. The densities of abundant species including N₂, CH₄ and H₂ are determined directly from their main channels. However, to untangle the overlapping cracking patterns of minor species, the technique of Singular Value Decomposition (SVD) is used to determine simultaneously the densities of various hydrocarbons, nitriles and oxygen compounds. All minor species except for ⁴⁰Ar present density enhancements measured during the outbound legs. This can be interpreted as a result of wall effects, which could be either adsorption/desorption or heterogeneous surface chemistry on the chamber walls. In the thesis, I use a simple model to describe the observed time behavior of minor species. Results on their atmospheric abundances are provided both in terms of direct inbound measurements assuming ram pressure enhancement and values corrected for wall adsorption/desorption. Among all minor species of photochemical interest, the INMS data provide direct observational evidences for C₂H₂, C₂H₄, C₂H₆, CH₃C₂H, C₄H₂, C₆H₆, HC₃N and C₂N₂ in Titan’s upper atmosphere. Upper limits are put for other minor species. The globally averaged distribution of N₂, CH₄ and H₂ are each modeled with the diffusion approximation. The N₂ profile suggests an average thermospheric temperature of 154 K. The CH₄ and H₂ distribution constrains their fluxes to be 3.0×10⁹ cm⁻² s⁻¹ and 1.3×10¹⁰ cm⁻² s⁻¹, referred to Titan’s surface. The H₂ escape flux is about a factor of ∼3 higher than the Jeans value, which is interpreted as enhanced thermal escape driven primarily by an upward conductive heat flux. Such a conclusion is based on kinetic model calculations in the 13-moment approximation that require energy continuity at the upper boundary. On the other hand, a proper interpretation of the observed CH4 escape has to rely on the detailed nonthermal processes, which are still unknown at the present time. The INMS observations of the nitrogen isotope ratio implies ¹⁴N/¹⁵N= 131.6 near Titan’s surface. The profile of carbon isotope ratio combining INMS and GCMS results implies that both CH₄ and its isotope escape from Titan’s exobase with roughly the same drift velocity, in contrast to the Jeans case which requires that CH₄ escapes with a much larger velocity due to its smaller mass. The INMS data also suggest horizontal/diurnal variations of temperature and neutral gas distribution in Titan’s thermosphere. The equatorial regions, the ramside, as well as the nightside hemisphere of Titan appear to be warmer and present some evidences for the depletion of light species such as CH₄. Meridional variations of most heavy species are also observed, with a trend of depletion toward the north pole. Though some of the above variations might be interpreted by either the solardriven models or plasma-driven models, a physical scenario that reconciles all the observed horizontal/diurnal variations in a consistent way is still missing, With a careful evaluation of the effect of restricted sampling, some of the features shown in the INMS data are more likely to be observational biases.

Using large multiwavelength datasets, we study obscured AGN in the distant universe that have been missed via traditional selection techniques (e.g. UV/ optical/X-ray). To do so, we take particular advantage of the mid-IR, which is minimally affected by obscuration. We first select as AGN candidates those objects whose radio emission is significantly brighter, relative to the mid-IR, than would be predicted by the well known radio/infrared correlation, indicating that the radio emission originates in the central engine. We find that of the 27 such sources identified in the CDF-N, 60% lack solid X-ray detections and 25% lack even 2σ X-ray emission. The absorbing columns of the faint X-ray–detected objects indicate that they are obscured but unlikely to be Compton thick, whereas the radio-excess AGN which are X-ray non-detected are Compton-thick candidates. We similarly use the infrared emission to select IRAC (3.6-8.0 μm) power-law AGN. In these luminous AGN, the hot dust emission from the AGN fills in the gap in a galaxy’s SED between the 1.6 μm stellar bump and the long-wavelength dust emission feature. While sources selected in this way are more luminous than the radio-excess AGN, we find a similar X-ray detection fraction. Of the 62 power-law galaxies in the CDF-N, only 55% are detected in the X-ray, and 15% lack evidence for even weak 2σ X-ray emission. A study of their X-ray properties indicates that ∼ 75% are obscured. Finally, we test IRAC color-color and infrared-excess selection criteria. We find that while these selection techniques identify a number of obscured AGN, they may also select a significant number of star-forming galaxies. By combining only the secure AGN candidates selected via all methods discussed above, we estimate that the addition of Spitzer-selected AGN candidates to the deepest Xray selected AGN samples directly increases the number of known AGN by 54- 77%, and implies a total increase to the number of AGN of 71-94%.

Despite years of study, the origins of red galaxies are not fully understood in a cosmological context. We develop new models for quenching star-formation and producing red galaxies in cosmological hydrodynamic simulations. We start with phenomenological models applied in post-processing to previously-run simulations. We focus separately on mergers and hot haloes – akin to “quasar mode” and “radio mode” feedback – as the drivers shutting down star-formation. With appropriate parameter choices, each model can produce a reasonably good match observed color-magnitude diagrams and red galaxy luminosity functions at redshift zero. We uncover some difficulties with these models in general, including red galaxy stellar populations that appear too blue by 0.1 magnitudes in g − r due to a metallicity deficit. Building on the post-processing models, we develop quenching models for simulations that run on-the-fly. Again, we test merger quenching and hot halo quenching separately. We model merger feedback as > 1000 km s⁻¹ winds motivated by observations of post-starburst galaxies, and wemodel hot halo feedback by continuously adding thermal energy to circum-galactic gas in haloes dominated by gas above 250, 000 K. Merger quenching temporarily shuts down starformation, butmerger-remnant galaxies typically resume star-formation with 1− 2 Gyrs thanks to accretion of newfuel fromthe IGM.Hot halo quenching successfully produces a realistic red sequence, providing a good match to the observed red galaxy luminosity function. Despite some minor difficulties with hot halo quenching, we examine its effects in more detail. Specifically, we study the evolution of the simulated red sequence over time. We find that galaxies with stellar mass ∼ 10¹¹M⊙ are the first to populate the red sequence at z ≳ 2, with significantly fewer red galaxies around 10¹⁰M⊙ until z ≈ 0. We show that massive galaxies grow substantially after moving onto the red sequence, primarily through minor mergers. We also examine the relationship between quenching and environment.