"MOSFIRE, the Multi-Object Spectrometer for Infrared Exploration at Keck Observatory"
MOSFIRE is a powerful and unique near-infrared (0.9-2.4 microns) instrument for the Keck 1 telescope on Mauna Kea. MOSFIRE is both a camera and a spectrograph. The camera can image a field of view of 6.1 x 6.1 arcminutes with 0.18 arcseconds per pixel sampling. Up to 46 objects in the central 6 x 4 arcminute field can then be isolated using a cryogenic configurable slitmask unit (CSU) located inside the vacuum chamber. When a mirror is switched to a diffraction grating, the spectra of all 46 objects are recorded simultaneously. For a slit width of 0.7 arcseconds (2.9 pixels), MOSFIRE achieves a resolving power of R~3,500. Observations are possible in the Y, J, H or K bands using only two grating settings, and a single HgCdTe 2K x 2K detector. Because of the cryogenic CSU, slit masks can be reconfigured under computer control in about six minutes. This unique mechanism completely eliminates the time and risk associated with a thermal cycle of the instrument to room temperature in order to exchange batches of previously-milled metal masks. Built by a consortium of UCLA, Caltech, UCSC and WMKO, together with industrial partners, MOSFIRE was a challenging instrument for many reasons. The project took almost 8 years to complete. I will describe how the most important problems were solved, and I will illustrate MOSFIRE's excellent on-sky performance. MOSFIRE has been in regular use by the community since February 2013.
University of California, Los Angeles
host: Gregory Mace