Rapport M/L de disques de galaxies issus de modèles CSPE et contrôle des contraintes mécaniques dans la conception de revêtements optiques
The following thesis includes two parts: the first concentrates on mass models of galaxies while the second concerns the design of broadband optical coatings and the control of their mechanical properties.  Mass models presented here were performed on a subsample of ten galaxies from the SINGS survey.  It includes nine late-type regular galaxies as well as a dwarf galaxy. The work consisted in the determination at all radii of M/L ratio of galactic discs by choosing, amongst a grid of chemospectrophotometric galactic evolution models, the one that fits better the galaxy's multi-band photometric profile. Results from this work show that stellar discs weighted by the model's mass-to-luminosity ratio display consistent masses in all studied bands from the ultraviolet to the near-infrared (FUV to IRAC2 bands). The resulting discs are physically motivated and maximal, due to their mass-to-luminosity ratio being higher in the center of the galaxies than at their outskirts. In this maximal-disc situation, bars and bulges of galaxies can no longer be ignored and the appropriate corrections need to be made on the luminosity or circular velocity profiles of the galaxy.  In the second part, an additional module of the open source software Open Filters was written in order to take into account the mechanical properties of thin films in the design of optical coatings.  The mechanical stresses arising in optical coatings can have a deleterious effect on the optical performances of coatings, and this tool was meant to provide design capacities to minimize this effect. Broadband reflective coatings for Fabry-Perot plates were designed and fabricated as a proof of concept of the method. This specific case was interesting because the curvature induced by mechanical stresses induces decrease of the finesse of Fabry-Perot etalons.  Actual curvature of the deposited samples are coherent with the numerical calculations and undergo a substantial reduction for the two strategies devised here with this new design too. We therefore conclude that it is possible with this new software module to optimize coatings for their mechanical behaviour as well as for their optical properties.
Galaxies kinematics Mass/luminosity ratio Chemo-spectrophotometric evolution models Astronomical instrumentation Optical coatings Mechanical properties of thin films Numerical coating design