Updated on May 28, 2021, 11:15 am
ARCoIRIS is a cross-dispersed spectrograph featuring six spectral orders, spanning 0.8 - 2.4 microns, which are represented by distinct X-Y loci projected onto the science detector. In photometric terms, one can think of each spectral order as being approximately equal to the 2MASS-like JHK filters, the Y-filter and the Sloan z' filter, viz, K=3, H=4, J=5, Y=6 and z'=7/8 (see the figure below). The start and end-point wavelengths are shown for each spectral order.
A raw, first light ARCoIRIS spectrum of the V=8-mag. A0V star HD 138295, showing the X-Y traces on the science array of the six cross-dispersed spectral orders. Start and end-point wavelengths are shown on a per-spectral order basis.