Trou noir supermassif

vignette|En haut : vue d'artiste d’un trou noir supermassif absorbant la matière environnante. En bas : images supposées d'un trou noir dévorant une étoile dans la galaxie . Photo en avec le télescope Chandra à gauche ; photo optique prise par le VLT de l'ESO à droite. Un trou noir supermassif (TNSM) est un trou noir dont la masse est de l'ordre d'un million de masses solaires ou plus. Il constitue l’un des quatre types de trous noirs avec les trous noirs primordiaux, les trous noirs stellaires, les trous noirs intermédiaires. Étant les plus massifs, leur masse peut atteindre jusqu'à de masses solaires (ainsi celui de la galaxie ). Les trous noirs supermassifs se trouvent au centre des galaxies massives et c'est un quasi consensus dans la communauté scientifique que chaque grosse galaxie abrite un tel objet. C'est le cas au centre de notre galaxie, la Voie lactée, qui abrite un tel trou noir supermassif, à savoir la source . Trous noirs supermassifs au centre des galaxies

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Trou noir

alt=|vignette|Le disque d'accrétion du trou noir M87* imagé par l'en. Le trou noir lui-même est invisible, au centre de la zone noire centrale. En astrophysique, un trou noir est un objet céleste si

Galaxie

vignette|redresse=1.5|M51, la Galaxie du Tourbillon, un exemple typique de galaxie spirale. Une galaxie est une structure cosmique formée par le rassemblement d'étoiles et de leurs planètes éventuel

Voie lactée

La Voie lactée, aussi nommée la Galaxie (avec une majuscule), est une galaxie spirale barrée qui comprend entre 200 et d'étoiles, et sans doute plus de de planètes. Elle abrite le Système solaire e

Multi-object spectroscopic operations with the Sloan Digital Sky Survey V

Ricardo Jorge Araùjo Pereira, Loïc Grossen, Luzius Gregor Kronig

The Sloan Digital Sky Survey V (SDSS-V) is an all-sky spectroscopic survey of more than 6 million objects, designed to decode the history of the Milky Way, reveal the inner workings of stars, investigate the origin of solar systems, and track the growth of supermassive black holes across the Universe. SDSS-V presents significant innovations in both hardware and software, chiefly due to the introduction of a robotic Focal Plane System (FPS) that replaces plug-plate operations. This new mode of operations introduces new challenges with respect to target scheduling, fibre robot positioner reconfiguration optimisation, telescope guiding, observer interfaces, and observatory operations. During normal operations SDSS-V will observe a new field every 15 minutes. For each field requiring a new telescope pointing the FPS will reconfigure 500 robotic fibre positioners with feedback from an external Field Viewing Camera (FVC) in less than two minutes. Six CCD cameras mounted on the FPS will be used to automatically acquire the field and maintain the necessary guiding accuracy. These strict requirements highlight the need for streamlined operations software and procedures to minimise the time spent during FPS reconfigurations. We describe the overall design and implementation of the SDSS-V survey operations, with special emphasis on software development, conventions, and observing procedures. While specific to SDSS-V, the solutions we describe can be readily applied to other astronomical surveys and are of special interest given the rapid increase in projects employing robotic fibre positioners.

SPIE-INT SOC OPTICAL ENGINEERING2020

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Fabrication of glass suspended microchannel resonators

The goal of this project was to study if the fabrication of glass suspended microchannel resonators was possible. Through trial and error, the process parameters were determined, starting from the ideal dose in the dry etching process. The ideal size was determined by choosing a dose that guaranteed that all holes were properly opened, while keeping the critical dimensions (CD). This allowed us to keep holes small enough to be able to fill them later on in the process. The ideal was found to be 24 mJ/cm2. The next step of the project was to determine the right cleaning methods of the microchannels. After some unfruitful attempts, a cleaning process that worked was found. Its main steps are HF 1% during 3 minutes, followed by 1 minute in a KOH 9:1 IPA bath at room temperature. Finally, sputter deposition and LPCVD were tested to close the microchannels, with both presenting some advantages and disadvantages. During this final step, the stress buildup in the SiO2 film showed, creating cracks in the membrane. For this reason, this process flow is not viable to fabricate glass suspended microchannel resonators.

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The Industrialization of Astronomical Instrumentation: An Industrial Systems and Process Engineering Perspective

Ricardo Jorge Araùjo Pereira, Mohamed Bouri, Loïc Grossen, Jean-Paul Richard Kneib, Luzius Gregor Kronig

The Sloan Digital Sky Survey V (SDSS-V) is an all-sky spectroscopic survey of > 6 million objects, designed to decode the history of the Milky Way, reveal the inner workings of stars, investigate the origin of solar systems, and track the growth of supermassive black holes across the Universe. Collaboratively, organizations across both academia and industry have partnered to overcome technical challenges and execute operational directives associated with commissioning the various mechanical, electrical, and software subsystems of SDSS-V. While this type of collaboration is not unique, the scale and complexity of next generation astronomical instruments is an emerging challenge that requires industrial systems and process engineering practices at a quasi-industrial scale. Driven by the success of multiplexed spectroscopic surveys, instrumentation is evolving to include systems with hundreds to thousands of components and sub-assemblies procured or produced from various sources. This trend requires the adoption of new and existing processes and best practices in the design, integration, and test of next generation astronomical instruments. The following discussion outlines those industrial systems and process engineering processes, methods, and practices, currently in the operational phase, for the design, integration, and test of the SDSS-V Focal Plane System (FPS). An emphasis is placed on processes, methods, and practices related to coordination of multiple contract manufacturing vendors and operational execution of small batch manufacturing.

SPIE-INT SOC OPTICAL ENGINEERING2020

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PHYS-100: Advanced physics I (mechanics)

La Physique Générale I (avancée) couvre la mécanique du point et du solide indéformable. Apprendre la mécanique, c'est apprendre à mettre sous forme mathématique un phénomène physique, en modélisant la situation et appliquant les lois de la physique.

PHYS-402: Astrophysics IV : observational cosmology

Cosmology is the study of the structure and evolution of the universe as a whole. This course describes the principal themes of cosmology, as seen from the point of view of observations.

PHYS-427: Relativity and cosmology I

Introduce the students to general relativity and its classical tests.