Change page style: 

Spectral Range and Resolution

You are here

The full GRACES spectral is 400-1,050 nm. The useful range is 420-1,010nm, and the GRACES sensitivity is at its best between 490nm and 950 nm (see the Sensitivity page for more details).

This figure shows the raw 2D spectrum of the A3 star HIP 57258. It also is the GRACES phase I first light! 


The spectral resolution was calculated based on ~100 lines of an observed ThAr lamp spectrum. The average pixel size for the one-fiber mode is 1.74 pixels, giving an average resolution power of R~67,500. For the two-fiber mode, we get 2.88 pixels per resolution element, giving a resolution power of ~40,000. The figure below shows the resolution as a function of the wavelength, from 4500 to 8500 angstroms. The solid lines are the averages for each mode, and the shaded areas represent ±1 sigma from the mean values.


Resolution of the two GRACES modes