The Near Infrared Camera and Multi-Object Spectrometer, NICMOS, provides HST with infrared imaging and spectroscopic capabilities between 0.8 and 2.5 microns. Above the earth’s atmosphere, NICMOS provides access to this complete spectral range without hindrance from atmospheric emission or absorption at a sensitivity and angular resolution not possible from the ground. The sky background for NICMOS is much more stable and 100 to 300 times lower in the
J and
H bands than for ground-based telescopes (refer to
Figure 4.17). It is a factor of 1.5 to 2 times lower in the
K band.
NICMOS, which operated from February 1997 until November 1998 using an onboard exhaustible cryogen, was revived with the installation of the NICMOS Cooling System (NCS) during the Servicing Mission SM3B, in February 2002. The NCS provides active cooling through a series of closed circuit loops containing cryogenic gas.
This Handbook provides the instrument specific information needed to propose HST observations (Phase I), design accepted proposals (Phase II, in conjunction with the Phase II Proposal Instructions), and understand NICMOS in detail. The Handbook has been revised from its original versions to include the performance with the NCS.
This chapter explains the layout of the Handbook and how to get additional help and information through the Help Desk and STScI World Wide Web pages. It also lists the supported capabilities of NICMOS and includes basic recommendations on how to use the instrument.
