Interview:
At the near-infrared wavelength range, the night
sky of the Earth is very bright due to emission
lines of OH molecules. OHS has a unique capability
in that it creates a high dispersion spectrum,
removes unwanted light with wavelengths corresponding
to OH molecular lines, and then recreates a low-dispersion
spectrum. The OH suppression increases the effective
sensitivity of the spectrograph by a factor of
2.5.
UV and optical light from distant
galaxies are red-shifted into near-infrared wavelengths
because of the expansion of the Universe. Near-infrared
spectroscopy of distant galaxies has been extremely
difficult not only because distant galaxies are
faint, but also because the sky is bright in this
wavelength range. OHS makes it possible to detect
these objects.
The instrument is in constant
stand-by at the Infrared-Nasmyth focus of Subaru
Telescope, and can be ready for observation anytime.
CISCO can be used alone as a near-infrared camera,
and was one of the cameras used at First Light.
(From
a late 2002 interview with OHS/CISCO support scientist
Kentaro Aoki.)
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S106 is a star forming region approximately 2000
light years from the Earth. There is a large massive
star called IRS4 (Infrared Source 4) at the center
of S106. The star is approximately one hundred
thousand years old, and it is 20 times more massive
than the Sun. The hourglass shape of S106 is a
result of the way material is flowing outward
from the central star. A huge disk of gas and
dust surrounding IRS4 produces the construction
at the center.
This CISCO near-infrared image of an area of the
sky called the Subaru Deep Field (SDF) shows some
of the faintest galaxies ever observed, down to
a magnitude of 24.5 in K’-band. Models of
galaxy evolution predicting haw many galaxies
would be messed in deep images suggest that the
galaxies in the SDF image account for more than
90% of the total near-infrared light from all
the galaxies in the universe along this line of
sight.
