Astronomical instrumentation

Abstract:

SINFONI, the SINgle Faint Object Near-infrared Investigation, is an instrument for the Very Large Telescope (VLT), which will start its operation mid 2002 and allow for the first time near infrared (NIR) integral field spectroscopy at the diffraction limit of an 8-m telescope. SINFONI is the combination of two state-of-the art instruments, the integral field spectrometer SPIFFI, built by the Max-Planck-Institut fur extraterrestrische Physik (MPE), and the adaptive optics (AO) system MACAO, built by the European Southern Observatory (ESO). It will allow a unique type of observations by delivering simultaneously high spatial resolution (pixel sizes 0".025 to 0".25) and a moderate spectral resolution (R similar to 2000 to R similar to 4500), where the higher spectral resolution mode will allow for software OH suppression. This opens new prospects for astronomy.

Abstract:

One of the most important techniques for astrophysics with adaptive optics is the ability to do spectroscopy at diffraction limited scales. The extreme difficulty of positioning a faint target accurately on a very narrow slit can be avoided by using an integral field unit, which provides the added benefit of full spatial coverage. During 1998, working with ALFA and the 3D integral field spectrometer, we demonstrated the validity of this technique by extracting and distinguishing spectra from binary stars separated by only 0.26 ". The combination of ALFA&3D is also ideally suited to imaging distant galaxies or the nuclei of nearby ones, as its field of view can be changed between 1.2 " x1.2 " and 4 " x4 ", depending on the pixel scale chosen. Ln this contribution we present new results both on galactic targets, namely young stellar objects, as well as extra-galactic objects including a Seyfert and a starburst nucleus.

Abstract:

Conducting resolved spectroscopy on large samples of very faint objects is a strong requirement for the Next Generation Space Telescope (NGST). We are presenting the IFMOS concept, a 1 to 5 microns integral field spectrograph developed under contract with ESA. Image slicers are feeding compact spectrograph modules with very few moving parts. The wide field survey mode has low spatial - low spectral resolution over a field similar to 46 x 40 arcsec(2) (0.19 arcsec per resolved element). The high spatial -high spectral resolution mode covers a field 3.8 x 2.6 arcsec(2) sampled at 0.05 arcsec, a pointed object mode at the diffraction limit of the telescope. A detailed opto-mechanical design has been produced, meeting the environmental requirements for the NGST payload.