The Instrument

SAURON (Spectrographic Areal Unit for Research on Optical Nebulae) is a panoramic integral-field spectrograph using a lenslet array based on the TIGER principle (Bacon et al. 1995; see also the OASIS webpage). It is a dedicated instrument, mounted on the William Herschel Telescope (WHT) on La Palma. SAURON has a large field-of-view, high throughput, and allows simultaneous sky subtraction. Its design is optimized for studies of the stellar kinematics, gas kinematics, and line-strength distributions of nearby spheroids (de Zeeuw et al. 2002). Associated with it is an extensive data reduction and analysis software, XSauron, which was developed at CRAL to obtain fully calibrated spectra and the associated kinematic and line-strength measurements (Bacon et al. 2001).


Spatial sampling0.94"0.27";
Field-of view 41"x33"11"x9"
Spectral resolution (FWHM)4.2 Å3.6 Å
Spectral window4810-5350 Å

Wavelength coverage4500-7000 Å
Number of object lenslets1431
Number of sky lenslets146
Grism514 lines mm-1
Spectral sampling1.1 Å pix-10.9 Å pix-1
Instrumental dispersion105 km s-190 km s-1
Spectral separations/PSF ratio1.42.3
Main spectral featuresHβ, [OIII], Mgb, FeI, [NI]
TelescopeNe, Ar, W
DetectorEEV12 2148x4200
Pixel Size13.5 µm
Efficiency (instrumental/total)35/15%

The TIGER principle