SINFONI - Integral field spectroscopy at 50 milli-arcsecond resolution with the ESO VLT

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. 1. SINFONI: ADAPTIVE OPTICS AND INTEGRAL FIELD SPECTROSCOPY SINFONI (SINgle Faint Object Near-IR Investigation) is an adaptive optics assisted near infrared integral field spectrometer mounted to the European Southern Observatory (ESO) VLT (Very Large Telescope). The instrument is a combination ofthe Adaptive Optics module [1], a clone ofMACAO (Multiple Application Curvature Adaptive Optics), developed and built by ESO, and of the near infrared integral field spectrograph SPIFFI (SPectrograph for Infrared Faint Field Imaging) [2], developed and built by the Max-Planck-Institute for extraterrestrial Physics (MPE).Currently, ESO offers two state-of-the-art near infrared instruments at the VLT: ISAAC [3] for seeing limited infrared imaging and spectroscopy, and NAOS/CONICA [4,5] for high order adaptive optics imaging and low-resolution spectroscopy. However, spectroscopy of faint objects with diffraction limited angular resolution at an eight-meter telescope will strongly benefit from a dedicated instrument, which combines the following characteristics: first, diffraction limited observations at near infrared wavelengths, optimized for faint wave-front reference stars and laser guide star operations; second, instantaneous spectroscopy of a two dimensional field with sufficiently high spectral resolution for deep observations between the night sky emission lines.Both partner institutes collected extensive experience with diffraction-limited spectroscopy with their instruments ADONIS/SHARP [6] at the La Silla 3.6 m telescope, and ALFA/3D [7] at the Calar Alto Observatory 3.5 m telescope. Our conclusion is that when observing with adaptive optics, integral field spectroscopy gains significantly over long-slit spectroscopy and Fabry-Perot imaging. The latter suffers significantly from the variation of the sky emission and the point-spread-function (PSF) between consecutive images, and consumes exorbitant observing time for large wavelength coverage. Long-slit spectroscopy, on the other hand, lacks the essential two-dimensional information for decomposing the spatial flux distribution, and loses most ofthe source flux for a diffraction limited slit width and moderate correction of the atmospheric aberrations. In addition, flexure within the instruments complicates the acquisition of...

THE SINS SURVEY: MODELING THE DYNAMICS OFz∼ 2 GALAXIES AND THE HIGH-zTULLY-FISHER RELATION

“…In the framework of the SINS survey (see Förster Schreiber et al 2006;Förster Schreiber et al 2009;Genzel et al 2006Genzel et al , 2008Bouché et al 2007;Shapiro et al 2008), we used the SINFONI NIR integral field spectrograph on the ESO VLT (Eisenhauer et al 2003;Bonnet et al 2004) to measure the dynamics of the warm gas in a substantial sample of over 60 redshift 1.5-3.5 massive star-forming galaxies, as traced by their Hα emission redshifted into the H band (z ∼ 1.5) and K band (z ∼ 2.2), or by [O iii] at z > 2.8.…”

Kinematic signatures of AGN feedback in moderately powerful radio galaxies atz~ 2 observed with SINFONI

“…We observed all MRCR-SUMSS galaxies with the NIR imaging spectrograph SINFONI (Eisenhauer et al 2003) SINFONI is an image slicer that operates between 1.1 μm and 2.4 μm. We used the seeing-limited mode with the largest available field of view of 8 × 8 and a pixel scale of 250 mas.…”

NGC 6240: merger-induced star formation and gas dynamics

“…SINFONI is a near-infrared integral field spectrometer (Eisenhauer et al 2003) which includes a curvature-based adaptive optics system (Bonnet et al 2004). For these observations the wavefront reference was provided by the Laser Guide Star Facility (Bonacini Calia et al 2006;Rabien et al 2004).…”