Neste trabalho são apresentados os resultados obtidos no desenvolvimento de um sistema eletrônico embarcado dedicado à aquisição de imagens astronômicas. Este sistema é composto principalmente por uma câmera científica astronômica, que abriga um detector de imagem do tipo EMCCD, e por um controlador eletrônico utilizado para a operação e leitura do detector de imagem. São detalhados os estágios que formam o sistema embarcado específico para um instrumento astronômico instalado no telescópico internacional SOAR, no Chile. Cada um destes estágios: sensor, câmera, controlador eletrônico, placa de aquisição de imagens e software, será descrito detalhadamente, desde uma revisão das alternativas de solução até as técnicas de operação de sensores, além da manipulação de controladores eletrônicos. São analisados detalhes referentes ao projeto da câmera, bem como a influência desses detalhes em seu funcionamento. Alguns resultados científicos já alcançados com sistemas embarcados equivalentes são expostos. Também são apresentados os resultados dos ensaios e trabalhos realizados em laboratório para este projeto, e os resultados atingidos com o instrumento já em operação no telescópio. / This work presents the results obtained in the development of an embedded electronic system dedicated to the acquisition of astronomical images. This system consists primarily of a scientific astronomical camera, which houses an imaging detector EMCCD, and an electronic controller used for operating and reading the imaging detector. The stages that constitute the embedded system specific to an astronomical instrument installed in the telescopic international SOAR, at Chile, are detailed. Each of these stages: sensor, camera, electronic controller, image acquisition board and software, is described in detail, from a review of alternative solutions to the technical operation of sensors, and manipulation of electronic controllers. Some details of the camera design are analyzed as well as its influence in the camera operation. Some scientific results already achieved with equivalent embedded systems are exposed. It also presents the results of laboratory tests and work done for this project, and the results achieved with the instrument already operating at the telescope.

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Neste trabalho são apresentados os resultados obtidos no desenvolvimento de um sistema eletrônico embarcado dedicado à aquisição de imagens astronômicas. Este sistema é composto principalmente por uma câmera científica astronômica, que abriga um detector de imagem do tipo EMCCD, e por um controlador eletrônico utilizado para a operação e leitura do detector de imagem. São detalhados os estágios que formam o sistema embarcado específico para um instrumento astronômico instalado no telescópico internacional SOAR, no Chile. Cada um destes estágios: sensor, câmera, controlador eletrônico, placa de aquisição de imagens e software, será descrito detalhadamente, desde uma revisão das alternativas de solução até as técnicas de operação de sensores, além da manipulação de controladores eletrônicos. São analisados detalhes referentes ao projeto da câmera, bem como a influência desses detalhes em seu funcionamento. Alguns resultados científicos já alcançados com sistemas embarcados equivalentes são expostos. Também são apresentados os resultados dos ensaios e trabalhos realizados em laboratório para este projeto, e os resultados atingidos com o instrumento já em operação no telescópio. / This work presents the results obtained in the development of an embedded electronic system dedicated to the acquisition of astronomical images. This system consists primarily of a scientific astronomical camera, which houses an imaging detector EMCCD, and an electronic controller used for operating and reading the imaging detector. The stages that constitute the embedded system specific to an astronomical instrument installed in the telescopic international SOAR, at Chile, are detailed. Each of these stages: sensor, camera, electronic controller, image acquisition board and software, is described in detail, from a review of alternative solutions to the technical operation of sensors, and manipulation of electronic controllers. Some details of the camera design are analyzed as well as its influence in the camera operation. Some scientific results already achieved with equivalent embedded systems are exposed. It also presents the results of laboratory tests and work done for this project, and the results achieved with the instrument already operating at the telescope.

Atualmente existem muitas evidências da presença de matéria escura no Universo. Estas motivaram a existência de vários experimentos para sua detecção. Entre os experimentos de detecção indireta de matéria escura, o PAMELA, o ATIC e o Fermi-LAT observaram recentemente excessos de elétrons e pósitrons no fluxo galáctico em relação ao esperado para estas partículas. Estes resultados podem ser explicados pela aniquilação de matéria escura com massas entorno a 1 TeV em nossa galáxia, com produção de léptons. No entanto, para tal, estas observações requerem um aumento na taxa de aniquilação relativa à esperada da produção térmica de matéria escura. Este aumento pode ser devido a existência de subestruturas de matéria escura no halo galáctico ou a mecanismos de interação, como o efeito Sommerfeld, que aumentam a seção de choque de aniquilação das partículas de matéria escura. Neste _ultimo caso, deve ocorrer também um aumento na taxa de neutrinos provenientes da aniquilação de matéria escura no núcleo da Terra. Neste trabalho, estimamos as taxas destes neutrinos e usamos os resultados finais do AMANDA-II e resultados recentes de IceCube para testar cenários genéricos que contemplam um aumento na seção de choque de aniquilação. Apresentamos os nossos resultados em função da seção de choque de interação da matéria escura com os núcleos multiplicada pela fração da aniquilação das partículas de matéria escura em neutrinos e, também em função de um fator genérico de boost que parametriza o aumento na seção de choque de aniquilação. Encontramos que modelos de matéria escura requerem fatores de boost da ordem O(100) ou mais e que se aniquilam significativamente em neutrinos são excluídos como explicação dos excessos leptônicos medidos. / Currently there are many evidences of the existence of dark matter in the Universe. These led to experimental dark matter searches and, among them, some indirect detection experiments, PAMELA, ATIC and Fermi-LAT, have recently observed excesses in the galactic flux of electrons and positrons relative to the expected flux of these particles. These results could be explained by dark matter, with masses of the order of 1 TeV, annihilating into leptons in our galaxy. However, in order for this to explain the mentioned excesses, it is required that the dark matter annihilation rate is greater than the implied rate assuming the expected dark matter thermal annihilation cross section. This greater rate could be due to the presence of dark matter substructures in the galactic halo or due to interaction mechanisms, such as the Sommerfeld effect, that enhance the dark matter annihilation cross section. In the latter case, an enhancement in the neutrino flux from annihilation of dark matter particles in the Earth nucleus should also occur. In this work, we use the final results of AMANDA-II and recent results of IceCube to probe generic enhancement scenarios. We present results as a function of the dark matternucleon interaction cross section weighted by the branching fraction into neutrinos, and as a function of a generic boost factor, which parametrizes the expected enhancement of the annihilation rate. We find that dark matter models that require boosts factors of O(100) or more and that annihilate mainly into neutrinos are excluded as a explanation for the observed leptonic excesses.

Obtaining a very high level of precision and sophistication in automated computer control is now available inexpensively from a variety of hardware and software sources. Applying this automated technology to an astronomical telescope broadens the scope of applications of the instrument, particularly in areas such as photo electrics, CCD imaging and remote control. The ultimate design goal of the UWS telescope was that of full roboticism, giving access of the facility to off campus clients both in Australia and overseas. The first phase towards full robotic control is automation of the required optical and mechanical parameters, providing precision targeting and object tracking. This thesis describes the mechanical aspects of the UWS telescope and the procedures and equipment involved in its automation, including the drive system, electro mechanical design and associated computer hardware and software. Sample performance test data shows that using a high percentage of inexpensive proprietary robotics components, a very sophisticated and accurate measuring device can be produced. / Master of Science (Hons.)

All future Extremely Large Telescopes (ELTs) will be segmented. However, as their size grows, they become increasingly sensitive to external disturbances, such as gravity, wind and temperature gradients and to internal vibration sources. Maintaining their optical quality will rely more and more on active control means. This thesis studies active optics of segmented primary mirrors, which aims at stabilizing the shape and ensuring the continuity of the surface formed by the segments in the face of external disturbances. The modelling and the control strategy for active optics of segmented mirrors are examined. The model has a moderate size due to the separation of the quasi-static behavior of the mirror (primary response) from the dynamic response (secondary, or residual response). The control strategy considers explicitly the primary response of the telescope through a singular value controller. The control-structure interaction is addressed with the general robustness theory of multivariable feedback systems, where the secondary response is considered as uncertainty. Scaling laws allowing the extrapolation of the results obtained with existing 10m telescopes to future ELTs and even future larger telescopes are addressed and the most relevant parameters are highlighted. The study is illustrated with a set of examples of increasing sizes, up to 200 segments. This numerical study confirms that scaling laws, originally developed with simple analytical models, can be used in confidence in the preliminary design of large segmented telescopes.

La historia de la astronomía de los rayos gammas en los últimos veinte años está marcada por el éxito que los telescopios Cherenkov han tenido en la exploración de la banda de muy altas energías. La ultima generación de telescopios Cherenkov, que incluye los telescopios HESS, VERITAS y MAGIC, ha logrado, en sólo siete años, aumentar el número total de fuentes conocidas de muy altas energías, desde unas pocas hasta más de un centenar. Esta populación de fuentes incluye objetos galácticos y extragalácticos. Los telescopios Cherenkov se han demostrado muy eficientes en el descubrimiento de nuevas emisoras de rayos gammas y también en el estudio detallado de la propiedades físicas de las fuentes bien conocidas, como por ejemplo, la Nebulosa del Cangrejo, el prototipo de los pleriones o Nebulosas de Viento de Púlsar ("pulsar wind nebulae"). Gracias a su brillo a todas las longitudes de onda, el Cangrejo es una fuente astrofísica de referencia. Su espectro ha sido medido en veinte ordenes de magnitud en energía, desde las frecuencias radio hasta las muy altas energías, pero nuevas medidas resultan aún esenciales para entender las contradicciones que surgen cuando se combinan los resultados de diferentes longitudes de onda. Finalizado del commissioning del segundo telescopio en el Otoño del 2009, y tras el comienzo de la toma de datos en modalidad estereoscopica, MAGIC ha mejorado significantivamente su rendimiento y alcanza el umbral en energía más bajo de todos los telescopios Cherenkov. Por lo tanto MAGIC es un instrumento ideal para medir el espectro de la Nebulosa del Cangrejo con una precisión sin precedentes a partir de 50 GeV. Este logro tiene una importancia extraordinaria para el astrofísica de muy altas energías y tiene el potencial de solucionar unos de los misterios aun no resueltos de esta fuente. Este es uno de los asuntos centrales de este trabajo de tesis. Por otro lado, MAGIC ha tenido también un impacto fundamental en el descubrimiento de nuevos objetos astrofísicos, y, con la mejora en sensibilidad del nuevo sistema de dos telescopios , este impacto será aún mas significativo. Entre las fuentes galacticas, los microcuásares constituyen unos de los mejores candidatos a emisores de rayos gammas. Su caracterización a muy alta energía aportaría información muy útil para entender la formación de chorros de partículas en objetos astronomicos. Aunque muchos modelos teóricos predicen esta emisión, aún no ha sido detectada. De hecho hay evidencias de que los tres sistemas binarios que se han detectado hasta la fecha por encima de 300 GeV son binarias de púlsares más que microcuásares. Sin embargo, el hecho que el microcuásar Cygnus X-3 haya sido detectado por encima de 100 MeV por los satélites AGILE y Fermi/LAT confirma que esta clase de objetos sigue siendo un objetivo interesente por la astrofísica de muy alta energía. En los últimos años, MAGIC ha dedicado un esfuerzo muy importante búsqueda de señales desde los microcuásares. Esta tesis presenta los resultados de las observaciones de dos de ellos: Cygnus X-3 y Scorpius X-1. Se han logrado extraer los limites superiores al flujo integral de estas dos fuentes más restrictivos hasta la fecha por encima de unos centenares de GeV. Para Cygnus X-3 en particular, se presentan además las primeras observaciones a estas energías totalmente simultáneas con la emisión detectada por los satélites. / of the Imaging Atmospheric Cherenkov Telescopes (IACTs) in the exploration of the Very- High-Energy (VHE) band. The last generation of IACTs have been capable to increase the total number of known VHE emitting sources from a few to almost one hundred in just seven years of operation. This population comprises galactic and extragalactic objects. IACTs have proved to be very effective in both the discovery of new emitters, as well as in the fine analysis of the physics properties of well established sources. Among them, the Crab Pulsar Wind Nebula is probably the best studied astrophysical object and the archetypal PWN. Due to its brightness at almost all wavelenghts, it is considered as an astrophysical candle. Despite the Crab Nebula broad-band spectrum has been thoroughly studied across twenty orders of magnitudes, from radio frequencies to VHE, further effort is needed to resolve the contradictions in the combination of all the multiwavelenght results. With the commissioning of the second MAGIC telescope in 2009 and the beginning of the operations in stereoscopic mode, the performance of the instrument improved dramatically, allowing MAGIC to reach the lowest ever energy threshold among all the existing IACTs, and describe the Crab Nebula spectrum with unprecedented precision down to 50 GeV. This achievement is of crucial importance for the VHE !-ray astrophysics in the pre-CTA era, since it can cast new light on some of the unsolved mysteries of one of its most established sources. On the other hand, MAGIC made a strong impact in the discovery of new VHE sources and, with the improved sensitivity of the stereoscopic mode, this will be even more so in the future. Among the galactic objects, Microquasars (MQs) constitute some of the best candidates for VHE emission, but despite several well accepted models predict such signal, it has not been detected. There are, in fact, evidences that the three binary systems which have been unambiguously detected at energies above few hundreds of GeV are binary pulsars rather than accreting microquasars. Nevertheless, the recent detection of the microquasar Cygnus X-3 above 100 MeV by both Agile and Fermi satellites, and the claim of short oneday flares from Cygnus X-1 reported by Agile confirmed that microquasars remain interesting targets for VHE telescopes. MAGIC made a strong effort in searching for VHE signals from microquasars, but found only a non-significant evidence of signal from Cygnus X-1 in 80 minutes of observation on September 24, 2006. MAGIC tried to detect similar flares in the following four years but the subsequent hundred more hours of observations were unsuccessful. Besides Cygnus X-1, MAGIC pointed at two other microquasar candidates, whose results are presented in this thesis: Cygnus X-3 and Scorpius X-1. The most constraining UL to the integral flux of these sources at the energy above few hundred GeV are provided. Further investigations are being planned to discover these sources at VHE in the next years.

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 Imaging TELescope at the Fred Lawrence Whipple Observatory (FLWO) on Mount Hopkins, Arizona. While the discovery of dark energy and most subsequent supernova cosmology has been performed using optical and Ultraviolet wavelength observations of SN Ia, a growing body of evidence suggests that NIR SN Ia observations will be crucial for future cosmological studies. Whereas SN Ia observed at optical wavelengths have been shown to be excellent standardizeable candles, using empirical correlations between luminosity, light curve shape, and color, the CfAIR2 data set strengthens the evidence that SN Ia at NIR wavelengths are essentially standard candles, even without correction for light-curve shape or for reddening. CfAIR2 was obtained as part of the CfA Supernova Program, an ongoing multi-wavelength follow-up effort at FLWO designed to observe high-quality, densely sampled light curves and spectra of hundreds of low-redshift SN Ia. CfAIR2 is the largest homogeneously observed and processed NIR data set of its kind to date, nearly tripling the number of individual \(JHK_s\) band observations and nearly doubling the set of SN Ia with published NIR light curves in the literature. Matched only by the recently published Carnegie Supernova Project sample, CfAIR2 complements the large and growing set of low-redshift optical and NIR SN Ia observations obtained by the CfA and other programs, making this data set a unique and particularly valuable local universe anchor for future supernova cosmology. / Astronomy

Extremely large telescopes (ELTs) are the next generation of ground-based reflecting telescopes of optical wavelengths. ELTs possess an aperture of more than 20 meters and share a number of common features, particularly the use of a segmented primary mirror and the use of adaptive optics systems. In 2005, the European Southern Observatory introduced a new giant telescope concept, named the European Extremely Large Telescope (E-ELT), which is scheduled for operation in 2018. The E-ELT will address key scientific challenges and will aim for a number of notable firsts, including discovering Earth-like planets around other stars in the ``habitable zones'' where life could exist, attempting to uncover the relationship between black holes and galaxies, measuring the properties of the first stars and galaxies, and probing the nature of dark matter and dark energy. In 2009, a feasibility study, conducted by National Instruments, proved the feasibility of the real-time (RT) control system architecture for the E-ELT's nearly 1,000 mirror segments with 3,000 actuators and 6,000 sensors. The goal of the RT control system was to maintain a perfectly aligned field of mirrors at all times with a loop-time of 1 ms. The study assumed a prescribed controller algorithm. This research report prescribes the optimal controller algorithms for large segmented telescopes. In this respect, optimal controller designs for the primary mirror of the E-ELT, where optimality is formulated in the [H-2] and [H-infinity] frameworks are derived. Moreover, the designed controllers are simulated to show that the desired performance metrics are met. / text

This thesis addresses high performance computing in Adaptive Optics (AO) simulation and the development and demonstration of a prototype AO instrument for future Extremely Large Telescopes (ELTs). Adaptive Optics systems are used on astronomical telescopes for correcting the blurring effects of atmospheric turbulence on incoming starlight, improving image quality to that of the diffraction limit of the telescope. Extremely Large Telescopes will have primary mirror diameters in the 20 - 40 m range, driving the need for technology development in two key areas, among others: 1) adaptive optics simulation, and 2) wide field adaptive optics (WFAO). The Linear Adaptive Optics Simulator (LAOS) is at the forefront of adaptive optics simulation, opening up the capability to simulate ELTs with integrated AO systems on a single computer. This is computationally expensive and time consuming, and thus simulator performance is very important and can determine the feasibility of simulating such systems at all. Efforts were made to improve the existing LAOS performance and bring a larger range of problem sizes and AO instrument concepts including WFAO into the realm of possibility. WFAO will take advantage of the larger light collection and spatial resolution capabilities of ELTs. One WFAO instrument approach that addresses this is Multi-Object Adaptive Optics (MOAO), which will provide localized correction around a number (5 - 40) of selected science objects spread around the field of view, enabling extragalactic studies otherwise very costly to implement with other WFAO techniques. However, there are several risks that need to be retired. Many elements of an MOAO system, such as the use of atmospheric tomography, MEMS mirrors, and woofer-tweeter control have all been demonstrated to work in different lab settings and are included in advanced instrument concepts. Open loop control, however, is perhaps the greatest risk to MOAO, introducing unique requirements on the AO system. The Victoria Open Loop Testbed (VOLT) serves as a demonstration of open loop control – both on-sky at the Dominion Astrophysical Observatory's 1.2 m telescope and in the lab – to facilitate the future development of MOAO. Our goal was to demonstrate open loop control with a simple on-axis natural guide star testbed.