<p dir="ltr">In this dissertation, we develop novel methods of performing shear measurements in individual exposures and apply them to images obtained from WIYN-ODI. We generalize forced photometry and call this new method forced measurement. This involves performing a single iteration of a traditional moment-matching algorithm with reasonable initial guess values and correcting for negative pixel values after background subtraction. We find that this allows us to make flux, shape, size, and ellipticity measurements at extremely low S/N < 1. We compare the performance of this method to existing approaches and find our method to be superior. A novel Monte Carlo PSF correction scheme is also introduced that allows us to dramatically increase the source density and hence perform more accurate weak lensing. These methods are then applied to measure shear across 411 ×30 individual exposures of the galaxy cluster Abell 2390. We find that we are successfully able to recover the main mass structures. We also find that we are able to recover the smaller galaxy groups over a very large field. Examining data from a variety of wavelengths and sources such as X-ray, Radio, and spectroscopic methods, we find Abell 2390 is likely to be a case of late-stage merger. The hot gas during the infall phase experienced friction causing loss of angular momentum and hence is almost merged with the main core. The Dark Matter (DM) cores, however, did not experience such friction and continue to be in the merger phase.In this dissertation, we develop novel methods of performing shear measurements in individual exposures and apply them to images obtained from WIYN-ODI. We generalize forced photometry and call this new method forced measurement. This involves performing a single iteration of a traditional moment-matching algorithm with reasonable initial guess values and correcting for negative pixel values after background subtraction. We find that this allows us to make flux, shape, size, and ellipticity measurements at extremely low S/N < 1. We compare the performance of this method to existing approaches and find our method to be superior. A novel Monte Carlo PSF correction scheme is also introduced that allows us to dramatically increase the source density and hence perform more accurate weak lensing. These methods are then applied to measure shear across 411 ×30 individual exposures of the galaxy cluster Abell 2390. We find that we are successfully able to recover the main mass structures. We also find that we are able to recover the smaller galaxy groups over a very large field. Examining data from a variety of wavelengths and sources such as X-ray, Radio, and spectroscopic methods, we find Abell 2390 is likely to be a case of late-stage merger. The hot gas during the infall phase experienced friction causing loss of angular momentum and hence is almost merged with the main core. The Dark Matter (DM) cores, however, did not experience such friction and continue to be in the merger phase.In this dissertation, we develop novel methods of performing shear measurements in individual exposures and apply them to images obtained from WIYN-ODI. We generalize forced photometry and call this new method forced measurement. This involves performing a single iteration of a traditional moment-matching algorithm with reasonable initial guess values and correcting for negative pixel values after background subtraction. We find that this allows us to make flux, shape, size, and ellipticity measurements at extremely low S/N < 1. We compare the performance of this method to existing approaches and find our method to be superior. A novel Monte Carlo PSF correction scheme is also introduced that allows us to dramatically increase the source density and hence perform more accurate weak lensing. These methods are then applied to measure shear across 411 ×30 individual exposures of the galaxy cluster Abell 2390. We find that we are successfully able to recover the main mass structures. We also find that we are able to recover the smaller galaxy groups over a very large field. Examining data from a variety of wavelengths and sources such as X-ray, Radio, and spectroscopic methods, we find Abell 2390 is likely to be a case of late-stage merger. The hot gas during the infall phase experienced friction causing loss of angular momentum and hence is almost merged with the main core. The Dark Matter (DM) cores, however, did not experience such friction and continue to be in the merger phase.</p>

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.<p><p>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.<p><p>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. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Subject of this master´s thesis is a station testing of Mobile automated astronomical system No. 1 (MAAS – 1). This system is used for measurement of astronomical coordinates by measurments of the stars. This thesis is focused on impact of some systematic effects, especially effects of inaccurate input geographic coordinates to resulting coordinates.

No description available.

Over recent years there has been an increase of the number of secure supermassive black hole (SMBH) detections. These SMBH measurements have lead astronomers to establish well defined empirical relationships between the SMBH mass and some of the properties of the host galaxy. The number of galaxies with SMBH mass measurements is currently limited to about 100. One approach of expanding the study of the SMBH is to use the empirical relations for estimating M[subscript(bh)] for larger samples of galaxies. The investigation of the SMBH population (or SMBH mass function) for large sample of galaxies in the nearby universe has helped to constrain the SMBH and the galaxy evolution. Previous estimates of the SMBH mass function at low redshift were produced mainly by combining the measurements of the galaxy luminosity or velocity function with one of the SMBH scaling relations. In the first part of the thesis I will present an independent construction of the nearby supermassive black hole mass function by applying the optical M[subscript(bh)]–L relation onto the Millennium Galaxy Catalogue (MGC). Additionally, in the second part I will provide photometric analysis of all UKIDSS galaxies for which SMBH masses have been measured. I will derive composite profiles of brightness, ellipticity and position angles of each galaxy. I will show that the Sérsic function fits the brightness profile of the majority of the elliptical galaxies and the bulge of disk galaxies and I will provide alternative multi-component fits when necessary. Then these photometric parameters will be used for constructing the M[subscript(bh)]–L relation in the near-IR and to investigate the M[subscript(bh)]–n relation. In the third part I will construct the near-IR SMBH mass function for the Galaxy and Mass Assembly (GAMA) survey. For this purpose I will apply the newly derived M[subscript(bh)]–L relation onto an elliptical subsample of K-band images. The advantage of this SMBH mass function is that during the M[subscript(bh)]–L construction I used the same quality images and techniques used on the GAMA survey. Apart from the M[subscript(bh)]–L relation, the M[subscript(bh)]–sigma relation was used as an alternative approach for a subsample of galaxies for which the velocity dispersions were available. Furthermore, I employed both local SMBH mass functions (MGC & GAMA) for estimating the SMBH mass density at redshift zero and accounted for the dependence of the total SMBH density on the look-back time by comparing with semi-analytic SMBH mass functions. Finally, from the SMBH mass density I estimated the baryon fraction that is locked into SMBHs.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / After briefly presenting the TRANSMED mission, the configuration of the Telemetry and Telecommand links is illustrated and the their dimensioning is analyzed. Both links operate at S-band with satellite grade standards. The system composition, the main equipment and the system growth potential are thereafter presented.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-02-16T20:59:48Z No. of bitstreams: 1 Dissertacao_stanley.pdf: 4369040 bytes, checksum: ed63301078418b326241edb9682820e8 (MD5) / Made available in DSpace on 2017-02-16T20:59:48Z (GMT). No. of bitstreams: 1 Dissertacao_stanley.pdf: 4369040 bytes, checksum: ed63301078418b326241edb9682820e8 (MD5) Previous issue date: 2016-08-26 / Interacting peculiar galaxies are objects that still require further studies because they play an important role in the processes of the evolution of galaxies. The knowledge of its location and properties constitutes a great benefit to the astronomical community. In this dissertation, we present an automatic method for identifying and classifying images of interacting galaxies at low redshifts for the Southern Hemisphere, based on the properties of stellar and interstellar extinction distribution as well as using a pattern recognition software called ?Wndchrm? on images from the 2MASS survey, in the near infrared for the filters: J, H and KS. The training phase was made with images of known interacting galaxies from the Arp &Madore Catalogue, Categories 1 and 2. After training, a validation was performed using images of a region of the sky with 573 square degrees, obtaining a hit of, approximately, 73% in the identification of galaxies identified by visual inspection as interacting. This rate can reach up 88% considering the comparison with previous know galaxy pairs of Category 2 of Arp &Madore Catalogue. The procedure was performed for an area of about 17.836 square degrees of the Southern Hemisphere, finding at least several hundred galaxy pairs as yet uncatalogued. / As gal?xias peculiares interagentes s?o objetos que ainda carecem de maiores estudos. Elas desempenham um papel importante nos processos de forma??o e de evolu??o das gal?xias. O conhecimento de sua localiza??o e propriedades, constitui um grande benef?cio para a comunidade astron?mica. Nesta disserta??o, apresentamos um m?todo autom?tico para identificar e classificar imagens de gal?xias interagentes a baixos redshifts para o Hemisf?rio Sul. Para tal, estabelecemos crit?rios baseados na distribui??o de estrelas e extin??o interestelar, assim como de objetos identificados no Cat?logo de fontes extensas do 2MASS. Usamos um software de reconhecimento de padr?es chamado Wndchrm em imagens do grande levantamento 2MASS no infravermelho pr?ximo para os filtros: J, H e Ks. A fase de treinamento foi feita com imagens de gal?xias interagentes conhecidas, do Cat?logo de Arp&Madore, das categorias 1 e 2. Ap?s o treinamento foi realizada uma valida??o com imagens de uma regi?o do c?u de 573 graus quadrados, obtendo uma taxa de acerto de, aproximadamente 73% na identifica??o de gal?xias previamente identificadas de forma visual como interagentes. Essa taxa aumenta para, aproximadamente 88% levando em conta pares da Categoria 2 previamente identificados no Cat?logo de Arp&Madore como pertencentes ? essa categoria. Executamos, o procedimento para uma ?rea de, aproximadamente 17.836 graus quadrados do Hemisf?rio Sul, encontrando, ao menos, v?rias centenas de pares de gal?xias ainda n?o catalogados.

Submitted by Denilton Machado da Silva null (deniltonfisico@hotmail.com) on 2017-03-28T23:04:28Z No. of bitstreams: 1 DISSERTACÃO DENILTON UNESP2017 01.pdf: 3984743 bytes, checksum: 8a0ce09b952876299038e5c1c7ea7bcc (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-29T18:10:54Z (GMT) No. of bitstreams: 1 silva_dm_me_prud.pdf: 3984743 bytes, checksum: 8a0ce09b952876299038e5c1c7ea7bcc (MD5) / Made available in DSpace on 2017-03-29T18:10:54Z (GMT). No. of bitstreams: 1 silva_dm_me_prud.pdf: 3984743 bytes, checksum: 8a0ce09b952876299038e5c1c7ea7bcc (MD5) Previous issue date: 2016-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / De acordo com pesquisas em ensino de ciências, nos últimos tempos, os alunos de forma geral, não compreendem e não desenvolvem as tarefas sobre os conceitos básicos de ciências, como por exemplo, relacionar um tema de Física com os acontecimentos rotineiros do dia a dia, assim como relacioná-lo com a Química ou Geografia. Uma possível hipótese está no fato de que o ambiente escolar frequentado pelos alunos, atualmente, está desconexo com os interesses e curiosidades que eles possuem em aprender. Estes interesses estão ligados apenas a conceitos imediatistas. Esta geração de alunos que está se moldando é conhecida como “geração tecnológica”. As simples experimentações em si realizadas em salas de aulas não refletem no real aprendizado para que os alunos desenvolvam competências e habilidades na elaboração de saberes científico. Os conteúdos são apenas direcionados para cumprir currículos em espaços de tempo cada vez mais reduzidos. Pela fundamentação teórica de David Ausubel, que relaciona a questão de materiais representativos e significativos no processo de ensino aprendizagem, foi proposta, nesta pesquisa, a discussão dos conceitos de Astronomia, em formatos de oficinas, na qual os alunos foram incentivados a criar o próprio conhecimento de forma construtivista por meio da metodologia mediadora na relação com os outros saberes como a Matemática, Geografia, História, Física incentivando a interdisciplinaridade. Os resultados obtidos nas oficinas foram gravados e transformados em material de mídia que foram hospedados em um canal para serem compartilhados via web. Este material está sendo utilizado para consulta e estudos atendendo o livre acesso de conteúdo agregando conhecimento na tentativa de atender a “sociedade do conhecimento” que está se moldando via Ead. / In agreement of recent science education research, recently, in general, students cannot understand and also can not develop their stuff about basic science concepts, such as make the relationship between Physics and something that happen day-by-day either relation with chemistry or geography. A possible hypothesis can be the fact of the scholar ambient could be disconnected from the interest and curiosities that they should be to learn. These interests are connected just only with immediatist concepts. The students generation that is coming is called “Technological generation”. The experiments did in classroom have not been enough to improve their scientific skills. The subjects are just specifically used to fulfill curricula in a short period of time (and this time have been reduced constantly or periodically or frequently). By the theoretical basis of David Ausubel, that related representative and significative materials in the teaching/ learnt process was proposed, in this Project, the discussion of about Astronomy concepts using workshop format, In which students were encouraged to create their own knowledge in a constructivist way through the mediator methodology in relation to other knowledge such as Mathematics, Geography, History, Physics encouraging interdisciplinarity. The results obtained in the workshops were recorded and transformed in media material that it can be shared in web. This material is being used for reference source and studies, providing free access to content, aggregating knowledge in an attempt to meet the "knowledge society" that is shaping through EAD.

Les études Galactiques nécessitent de grands échantillons d'étoiles dont la masse, l'âge, les abondances, la vitesse et la distance sont connues. Les observations spectroscopiques permettent de mesurer certains de ces paramètres et les autres sont soit déterminés par d'autres moyens, ou dérivés par le calcul. Le besoin d'échantillons statistiquement représentatifs a motivé la construction d'instruments, et la réalisation de grands relevés comme le SDSS, LAMOST et GAIA... Ces projets génèrent une énorme quantité de données que les méthodes d'analyse interactives traditionnelles ne peuvent pas gérer. Cela a motivé des efforts pour concevoir des méthodes automatiques. Mon travail a commencé dans ce contexte, et les objectifs étaient de développer et tester une méthode automatique, puis de l'appliquer à des spectres stellaires à moyenne résolution. La thèse comporte quatre sections : 1. Je présente le package informatique ULySS, et en particulier son application à la détermination des paramètres atmosphériques des étoiles. 2. Nous avons utilisé ULySS pour déterminer les paramètres atmosphériques des 1273 étoiles de la bibliothèque CFLIB. 3. Nous avons appliqué la même méthode sur des observations obtenus pendant la mise en service de LAMOST et nous avons préparé une base de données de spectres de références pour les relevés futurs avec cet instrument. 4. Nous avons cherché des étoiles présumées pauvres en métaux (MP) en se servant des données de vérification scientifique de LAMOST. Cette étude contribue à l'étude des étoiles MP dans la Voie Lactée et montre la faisabilité de ces recherches avec LAMOST et ULySS / Galactic studies require large samples of stars with known mass, age, abundance, spatial velocity and distance etc. Spectroscopic observations allow ones to measure some of these parameters and to derive the others. The need for statistically representative samples motivated the construction of instruments and the realization of large surveys like SDSS, LAMOST and GAIA... These projects bring an enormous quantity of data that the traditional interactive spectral analysis methods cannot handle. This triggered efforts to design automatic methods. My work started in this context, and the goals were to develop and test an automatic method and to apply it to medium resolution stellar spectra. The thesis contains four sections: 1. The ULySS package, and in particular its application to the determination of the atmospheric parameters of stars is presented. 2. We used ULySS to determine the atmospheric parameters of the 1273 stars of the CFLIB library. 3. We applied the same method on LAMOST commissioning observations and we prepared stellar spectral templates for the future surveys. 4. We searched new metal-poor (hearafter MP) stellar candidates from LAMOST commissioning observations. The result of these MP star candidates is a prelude to the feasibility of LAMOST's capability on searching and enlarging the sample of MP stars in the Milky Way

In the last decade, adaptive optics systems have been implemented on all the major ground based telescopes and have proven reliable tools for correcting the image to near the diffraction limit. However, the correction from these systems is limited to a narrow field of view. This dissertation address the challenges of widening the corrected field of single conjugate adaptive optics by properly using statistical information on the optical turbulence profile of the atmosphere above the telescope, and by optimizing the trade-off between image quality and field of view. Altair is the facility adaptive optics system for the 8-meter Gemini North telescope and marks the historical beginning of wide field adaptive optics. Its performance evaluation in Part One is the first on-sky comparison of sparse field images from an altitude-conjugated and a ground-conjugated deformable mirror. All of the other basic aspects of Altair's performance are characterized for use by the Gemini community to plan observations. We also study and report. on techniques for extrapolating the edge of the deformable mirror, a critical step in altitude-conjugated mode. In Part Two we develop a point spread function model for Ground Layer Adaptive Optics (GLAO) that is based on analytic forms of the phase power spectral density. This model has been used for feasibility studies of GLAO on Gemini, and the Thirty Meter Telescope (TMT), currently the most advanced extremely large telescope project. The TMT will be an adaptive telescope that has science goals for the huge 81 square arcminute field of the Wide Field Optical Spectrograph (WFOS). We will show that WFOS-GLAO provides useful gains and will operate in the very wide GLAO (VWGLAO) regime, which has no additional overhead for seeing improved operation. To identify the VWGLAO regime we use statistical turbulence profile models and examine anisoplanatism in terms of image quality metrics relevant to the science that GLAO will likely assist. The VWGLAO regime is where there are useful gains over the theoretical seeing limit for wide field science that measure data collection efficiency as proportional to the product of image quality and the field of view (solid angle). We also show that for many cases VWGLAO will not be impacted by lag anisoplanatism nor by wavefront sensor noise.