Galaxy formation and evolution

Abstract:

GalICS (for GALaxies In Cosmological Simulations) is a model of hierarchical galaxy formation which combines high resolution numerical simulations for the dark matter component with semi-analytic prescriptions for the baryonic matter. It provides us with an explicit cosmological framework to analyse observations of distant galaxies, and to understand how they evolve to become local galaxies. We use GalICS to build multi-wavelength mock galaxy catalogues which include clustering properties. We can compare them to the sample of Lyman Break Galaxies at z=3 ( Steidel et al., 1996), and to deep sub-mm surveys. The predictions of the model will be detailed, and show a good agreement with the available data.

Abstract:

We present results from a new and unique integral-field spectrograph, SAURON. It has a large field of view and high throughput and is primarily built for the study of stellar & gaseous kinematics and stellar populations in galaxies. Its aim is to carry out a systematic survey of the velocity fields, velocity dispersions, and line-strength distributions of nearby ellipticals, lenticular galaxies and spiral bulges.

Abstract:

SINFONI is an adaptive optics assisted near-infrared integral field spectrometer for the ESO VLT. The Adaptive Optics Module (built by the ESO Adaptive Optics Group) is a 60-elements curvature-sensor based system, designed for operations with natural or sodium laser guide stars. The near-infrared integral field spectrometer SPIFFI (built by the Infrared Group of MPE) provides simultaneous spectroscopy of 32 x 32 spatial pixels, and a spectral resolving power of up to 3300. The adaptive optics module is in the phase of integration; the spectrometer is presently tested in the laboratory. We provide an overview of the project, with particular emphasis on the problems encountered in designing and building an adaptive optics assisted spectrometer.

Abstract:

SPIFFI is the near-infrared integral field spectrograph of the SINFONI VLT instrument. SPIFFI uses an image slicer with plane mirrors as its integral field unit. The integral field unit consists of two stacks of mirrors, each with 32 mirrors, rearranging a two-dimensional field-of-view of 32 x 32 pixels into a one-dimensional pseudo slit, which is fed into a long-slit spectrograph. The image slicer is constructed solely, from Zerodur and is operated at a cryogenic temperature of 77 Kelvin. Only optical contacting is used for the assembly of the individual slicer mirrors and the image slicer on its base-plate. The special slicer mount holds the image slicer stress-free and compensates for the different thermal coefficients of expansion of the Zerodur image slicer and the Aluminium mount. Tests at room and cryogenic temperatures show the performance of the image slicer, the durability of the optical contacting technique, and the accuracy of the slicer mount.