What is NIIS?

As ever-larger telescopes are constructed, the research role of smaller telescopes (less than 4 meters) is increasingly directed towards wide-field surveys. At the same time, techonological developments in detector technology have made large-format, near-infrared arrays a reality. Together, these trends have opened up new research opportunities and so a proposal to build a wide-field, near-infrared camera at the University of Wyoming was undertaken in 2005/2006 and approved by the National Science Foundations Major Research Instrumentation program.

The 2.3 meter telescope of the Wyoming Infrared Observatory ( WIRO ) was originally designed for mid-infrared wavelengths using single element bolometer detectors. As a result it has a very high f-ratio at the Cassegrain focus (f/27), making the image scale too high for a medium-field Cassegrain instrument with modern array detectors. A new secndary was beyond the budget of the orignal project leaving a prime focus design as the only option for a medium/wide field instrument. However, this placed severe restrictions on the instrument design due to WIRO's small dome clearance. After several attempts the prime focus option was abandoned as well and so the camera was designed as a Cassegrain instrument with the hope that additional funds could be acquired for a new secondary for WIRO. In the meantime, the camera would be  a traveling instrument, with initial deployment at Apache-Point Observatory near Sunspot, New Mexico. At about this time the project manager (M. Pierce) was involved in an unsuccessful proposal to build an infrared spectrogragh to provide a ground-based platform for promoting the programable microshutter arrays developed for JWST. As a result, the infrared camera design was modified to allow for a spectroscopic option and NIIS was born.

The instrument is designed primarly for wide-field, near-infrared imaging surveys and will be based on a 2048x2048 Hawaii-II array. It contains a complement of broad-band filters for imaging and will include grisms for medium-resolution spectroscopy. The image scale will be 0.39 arcsec/pixel with a field-of-view of 13.4 arcmin on a side on the APO 3.5-meter telescope. The 3.5 meter telescope of the Astrophysical Research Consortium at Apache Point Observatory (ARC) will be the first home of NIIS. The telescope is Alt-Azimuth mounted with a f/10 Ritchey-Chretien design. The telescope is designed to be remotely operated via the internet using in-house software. NIIS will sit at Nasmyth focus, meaning the instrument will rotate with the motion of the telescope.