CIRPASS Introduction

CIRPASS is a near-infrared, medium resolution (R~3000) integral field unit spectrograph operating over the wavelength range 1.0-1.67um with good sensitivity. We have negotiated its use for semester 2003A as a visitor instrument on Gemini South. 

CIRPASS features an integral field unit (IFU) and a fiber-fed NIR spectrograph. The instrument provides 2D IR (J and H) spectroscopy in two different formats (~10 x 5 arcsec; see IFU configurations). The telescope beam goes through a changeable fore-optics which feed 490 hexagonal doublet lenses attached to fibers. The hexagonal lenses provide an area filling factor of 100% and project onto the sky in an elliptical arrangement.

A 400 l/mm grating provides 200nm wavelength coverage at about 0.44nm resolution (2 pixel per resolution element; resolving power R=3200) with the 1024x1024 array. 

As a visitor instrument, CIRPASS does not contain an on-instrument wavefront sensor and therefore guide stars, which are mandatory for all observations with Gemini, will need to be acquired using the facility peripheral wavefront sensor(s).


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Last update 26 August 2002; Phil Puxley