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CFHT Observatory Manual - Observatory (Sec.5) http://www.cfht.hawaii.edu/Instruments/ObservatoryManual/CFH...
technical run in September 1997 and the final acceptance as well as the first
astronomical observations were carried out in December 1997 and January 1998.
GriF
GriF is an upgrade to KIR that allows integral field spectroscopy in the K band, with
a spatial resolution at the diffraction limit of the telescope (~0.12") using PUEO, the
CFHT adaptive optics bonnette . It consists of a (warm) Fabry Perot interferometer,
coupled with a grism in the KIR filter wheel, that disperses the Fabry Perot orders. A
rectangular field selector in the focal plane (~6" x 36" on the sky) prevents the orders
from overlapping spatially on the detector.
The Fabry Perot Perot mode will be available for 2004A, although narrow band filters
will need to be used for order sorting . The focal plane wheel, which normally allows
for coronography, long slit spectroscopy and the cross dispersed mode is undergoing
major redesign and will not be available for 2004A.
CFHTIR
CFHT-IR is a general purpose 1024 x 1024 near-infrared camera for direct imaging at
the F/8 Cassegrain focus (0.2" pixels, 3.5’ FOV). It has also been in the past the
infrared detector for multi-object spectroscopy with OSIS. CFHT-IR has been
developed as a collaborative effort between Université de Montréal and CFHT.
Commissioning took place in November 2000 and CFHT-IR has been regularly used
for science since then.
MOS/OSIS
At a meeting in 1986, the CFHT users’ community identified a low spectral
resolution multi-object spectrograph as one of the highest priorities for new
instrumentation at CFHT. Although the original intermediate dispersion
spectrographs constructed for the CFHT had high throughput and were of excellent
optical and mechanical quality, they were designed for single slit observations with
image intensifiers or electronographic cameras as detectors. The desire to observe
many faint objects simultaneously and also the realization that the image quality at
CFHT is routinely better than one arcsecond led to the design of the MOS/SIS
spectrograph, a dual Multi-Object and Subarcsecond Imaging Spectrograph. It is
composed, in fact, of two distinct spectrographs sharing a common interface with the
telescope after the Cassegrain bonnette: one is optimized for multi-object
observations over a large field (MOS), the other (SIS) for high spatial resolution
observations incorporating rapid tip/tilt image stabilization similar to that very
successfully used in the CFHT/DAO high resolution camera HRCam (McClure et al.
1989). Two movable 45 degree mirrors permit a feed to either MOS or SIS. The
MOS/SIS spectrograph was jointly designed and built by teams from the Dominion
Astrophysical Observatory (DAO) in Victoria, theObservatoire de Paris-Meudon
(OPM), the Observatoire de Marseille andCFHT. Work began on the designs in May
1988 and resulted in an instrument which saw its first light in July 1992. For several
years from that time, MOS/SIS was the most popular instrument at CFHT. With the
advent of wide-field imaging and regular AOB observations, it has taken a smaller,
but still quite significant role in the observering schedule. MOS/OSIS have accounted
for 25 - 30 night per semester over the past few semesters (Sept 2001).
MOS is primarily designed for multi-aperture spectroscopy over a 10´ x 10´ field,
just covered with a 2048 x 2048 15 µm pixel CCD. This gives images with a correct
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