Observational cosmology with the large synoptic survey telescope: development of the camera calibration optical bench and baryon acoustic oscillations simulation
Description
More than ten years ago, the accelerated expansion of the Universe was discovered, by type Ia supernovae, and then confirmed by other probes. This discovery has changed our understanding of the energetic content of the Universe. Indeed, in order to explain such an acceleration, a new component has to be introduced and it must contribute to 70% of the total energy density. This component, so called Dark Energy, affects both cosmological distances and growth of structures from which galaxies originates. The main cosmological probes of dark energy are the type Ia supernovae, the galaxy cluster count, the weak gravitational lensing and the baryon acoustic oscillations. In order to precisely constrain theoretical models joint observations of all four probes are very efficient. The required level of precision on cosmological measurements is so high that a new generation of instruments is growing, among which the Large Synoptic Survey Telescope (LSST). With a primary mirror of 8.4 m diameter, it will cover half of the optical sky in six photometric bandpasses. Its camera will be the world biggest camera ever constructed. This thesis treats both an experimental and phenomenological aspects. Firstly, the work presented here consists in the development of the LSST camera calibration optical bench. We have have designed a system allowing both an efficient commissioning of the camera before its installation on the telescope, and a precise calibration of the focal plane. Preliminary measurements validating the design of the bench will be presented. Secondly, a detailed BAO simulation dedicated to LSST will be introduced. Its main goal is to predict the level of precision on the dark energy equation of state parameter reconstruction that will be reached with LSST. We will stress on the production of a mock photometric galaxy catalog and on the photometric redshifts computation. (author)
Abstract (French)
Il y a plus de dix ans que l'acceleration de l'expansion de l'Univers a ete mise en evidence grace aux observations des supernovae de type Ia, puis confirmee par d'autres sondes. Cette decouverte a change notre comprehension du contenu energetique de l'Univers puisque pour expliquer une telle acceleration, une composante supplementaire de matiere est necessaire et contribue a hauteur de 70% environ. Cette derniere est appele 'energie noire'. Elle affecte aussi bien les mesures de distance, que la croissance des sur-densites de matiere qui donnent naissance aux structures. Les principales sondes sensibles a la nature de l'energie noire sont les supernovae de type Ia, les amas de galaxies, les lentilles gravitationnelles, et les oscillations acoustiques des baryons (BAO). Afin de contraindre precisement les modeles theoriques donnant un sens physique clair a l'energie noire, l'observation conjointe de ces quatre sondes est tres efficace. Le niveau de precision sur la mesure des observables cosmologiques requis pour contraindre les parametres des modeles d'energie noire est tel qu'une nouvelle generation de projets a recemment vu le jour avec, notamment, le telescope LSST (Large Synoptic Survey Telescope). Avec miroir primaire de 8.4 metres de diametre, il produira un catalogue couvrant la moitie du ciel observable dans 6 bandes photometriques. Sa camera sera la plus perfectionnee jamais construite dans le monde. Cette these presente a la fois un aspect experimental et une etude phenomenologique. Le travail expose porte tout d'abord sur l'elaboration du banc d'etalonnage de la camera de LSST et sur des premieres mesures optiques validant le schema de principe du banc. Nous avons concu un systeme permettant a la fois une validation efficace de la camera avant sa mise en place sur le telescope et un etalonnage precis du plan focal. Nous presenterons ensuite une simulation detaillee des BAO dediee a LSST et tentant de predire a quelle precision les parametres d'energie noire pourront etre contraints. L'accent est mis sur la production d'un catalogue photometrique de galaxies simule ainsi que sur une methode de calcul des redshifts photometriques. (auteur)Files
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Additional details
Additional titles
- Original title (French)
- Cosmologie observationnelle avec le Large Synoptic Survey Telescope. Elaboration du banc d'etalonnage de la camera et simulation d'oscillations acoustiques de baryons
Publishing Information
- Imprint Pagination
- 191 p.
- Report number
- FRNC-TH--14125
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 54044043
- Subject category
- S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; S46: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- BARYONS; CALIBRATION; CAMERAS; COMPUTERIZED SIMULATION; ENERGY SPECTRA; INFLATIONARY UNIVERSE; INTERGALACTIC SPACE; INTERSTELLAR SPACE; LUMINOSITY; MAXIMUM-LIKELIHOOD FIT; MILKY WAY; OSCILLATIONS; PHOTOMETRY; RED SHIFT; TELESCOPES
- Descriptors DEC
- COSMOLOGICAL MODELS; ELEMENTARY PARTICLES; FERMIONS; GALAXIES; HADRONS; MATHEMATICAL MODELS; MATHEMATICAL SOLUTIONS; NUMERICAL SOLUTION; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; SIMULATION; SPACE; SPECTRA
Optional Information
- Notes
- 104 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses