FALCON: a new-generation spectrograph with adaptive optics for the ESO VLT

We present FALCON, a concept of new generation multi-objects integral field spectrograph with adaptive optics for the ESO VLT. The goal of FALCON is to combine high angular resolution (0.15 - 0.25 arcsec) and high spectral resolution (R≥5000) in the 0.8-1.8 μm wavelength range across the Nasmyth field (25 arcmin). Instead of compensating the whole field, the correction will be performed locally on each scientific object. This implies to use small miniaturized devices for adaptive optics correction and wavefront sensing. The main scientific objective of FALCON will be extragalactic astronomy. It will therefore have to use atmospheric tomography because the stars required for wavefront sensing will be in most of the cases far outside the isoplanatic patch. We show in this paper that applying adaptive optics correction will provide an important increase in signal to noise ratio, especially for distant galaxies at high redshift.

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