CRIRES
High-Resolution IR Echelle Spectrometer

Click on the image for a full sized display

• Instrument Status

• Science Verification

• Science Objectives

• Instrument Concept

CRIRES first commissioning was successfully performed in June 2006.

First light images and spectra and more information is available : HERE

A second and third commissioning is scheduled in August and October 2006.

Our goal is to be able to release the instrument for the next call for proposals.

Science Verification

The science verification (SV) for CRIRES is carried out following the: VLT   Science Verification Policy and Procedures . SV runs are interleaved with commissioning and test activities, taking place between August 2006 and April 2007. SV observer shall submit their proposals using the Science Verification proposal template Proposers are asked to provide at least a short summary of the science goal, coordinates and magnitudes of GS and science target, a finding chart, the observing wavelength ID, as specified in appendix A of the UM and DIT, NDIT settings of science detectors as computed with the exposure time calculator (see below).

Useful Links and manuals

• CRIRES exposure time calculator
• CRIRES User Manual (draft July 2006)

Science Objectives

A cryogenic high-resolution IR spectrograph has been conceived for the VLT in order to exploit the enormously enhanced sensitivity provided by a dispersive instrument with a large detector array at an 8 m telescope. The gain entails a quantitative and qualitative improvement of the observational capabilities. It can boost all scientific applications aiming at fainter objects, higher spatial (extended sources), spectral and temporal resolution.

The IR spectrograph will make previously inaccessible phenomena and objects available for spectroscopic studies. Table 1 presents a list of science objectives.

Table 1: Science Objectives

The cryogenic echelle will provide for:

• high-resolution spectroscopy in the 1-5 µm range
  at the VLT. This instrument employs the largest available grating for a

• spectral resolving power of >= 100,000
  with a 0.2 arcsec slit. Simultaneous spectral coverage is maximized through one or several large (1024 x 1024 pixel) detector arrays in the focal plane. The second array dimension is exploited for

• 1-dimensional spectral imaging
  along the ~ 50 arcsec slit

• Adaptive Optics
  to maximise SNR and spatial resolution.

Functionally, the instrument can be divided into four units. The fore-optics section provides for field de-rotation, cold pupil and field stops, curvature sensing adaptive optics, and slit viewing. The prism predisperser isolates one echelle order and minimizes the total amount of light entering into the high-resolution section. The high-resolution section comprises the collimator, the echelle which is tilt-tuned for wavelength selection, the camera providing the 0.1 arcsec/pixel plate scale, and the detector(s). The calibration unit outside the cryogenic environment contains light sources for flux/wavelength calibration and detector flatfielding.

Observational capabilities and predicted performance are given in Tables 2 and 3.

Table 2: Cryogenic Echelle Main Characteristics

Table 3: Performance Limits