NICMOS (Near-Infrared Camera and Multi-Object Spectroscopy) was installed on the Hubble Space Telescope during SM2 in 1997 and has been the observatory

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NICMOS PostSM4 Unique Capabilities

• T. Wiklind1, E. Barker2, E. Bergeron2, I.
  Dachevsky2, T. Dahlén1, R. de Jong2, H.
  McLaughlin2,
• Koekemoer2, N. Pirzkal1, G. Schneider3, B. Shaw2,
  D. Thatte2, A. Viana2, T. Wheeler2

1European Space Agency/Space Telescope Science
Institute 2Space Telescope Science
Institute 3Steward Observatory

• Introduction
• NICMOS (Near-Infrared Camera and Multi-Object
  Spectroscopy) was installed on the Hubble Space
  Telescope during SM2 in 1997 and has been the
  observatorys only nearinfrared instrument. It
  was initially cooled by solid nitrogen. The
  nitrogen was consumed prematurely in early 1999
  due to a thermal short in the dewar. In January
  1999 NICMOS warmed up and remained inactive until
  the installation of a mechanical cooling system
  in March 2002. With the NICMOS Cooling System
  (NCS) the NICMOS detectors have continued to
  operate at a stable temperature of 77.15K.
• NICMOS will continue to be one of the HST
  instruments after Servicing Mission 4 (SM4). A
  full functional verification, instrument
  re-characterization, and initial re-calibration
  will be carried out in SMOV4. It is expected that
  NICMOS will maintain all of its current observing
  modes in the coming cycles. It will no longer be
  the only instrument capable of NIR observations,
  but will be joined by the IRchannel in WFC3. The
  two NIR instruments, NICMOS and WFC3, will
  complement each other and together they will
  provide observers with a powerful and versatile
  near-infrared observing tool.

• Unique NICMOS Capabilities
• The NIR capabilities of the new WFC3 and NICMOS
  will compliment each other. The WFC3 IR channel
  will provide an efficient widearea coverage,
  with imaging and grism capability, for ?1.7?m.
  The NICMOS cameras have smaller field of views
  but provide diffraction limited imaging,
  coronagraphic and polarimetric capabilities, as
  well as access to wavelengths longer than 1.7?m
  for imaging, grism and polarimetric observations.
  
• Below we list six areas where NICMOS will provide
  unique capabilities for NIR observers after SM4
• Observations at wavelengths longer than 1.7?m
• NICMOS will be the only instrument
  capable of observing at ?gt1.7?m.
• This capability is available for all
  three NICMOS cameras in imaging
• mode. In addition, observations at
  ?gt1.7?m are also available for
• polarimetry, grism spectroscopy and
  coronagraphy (see below).
• Coronagraphy
• NICMOS is the only instrument providing
  coronagraphic capability
• at NIR wavelengths. Coronagrapy is
  provided with the NIC2 camera.
• Polarimetry
• NICMOS is the only instrument with
  polarimetric capabilities at NIR
• wavelengths, providing polarimetric
  imaging with high spatial resolution

NICMOS and SMOV4 Following the installation of
the NICMOS Cooling System (NCS) in March 2002,
the NICMOS detectors and filters have been
actively maintained at a stable temperature of
77.15K. During SM4 the NCS will be turned off,
and NICMOS will warm up. This thermal cycling
makes a complete verification of NICMOS
functionality and performance as well as
photometric and astrometric recalibrations
necessary. Once the HST is released from the
space shuttle, the NCS will be started and NICMOS
is expected to cool down to its nominal operating
temperature, with the detectors at 77.15K. At
this point the NICMOS SMOV4 activities will
commence. During SMOV4, the mechanical
functionality of the filter wheel mechanisms, the
Field Offset Mirror (FOM) and the Pupil Alignment
Mirror (PAM) will be tested. The optical
alignment and geometrical stability as well as
the focus and optical aberrations will be checked
and corrected if necessary. In addition, a
measurement of the biases and detector response
will be performed. Particular attention is given
to those capabilities which will be NICMOS unique
in the postSM4 era, such as coronagraphic
observations and a characterization of the long
wavelength thermal background. Following shortly
after SMOV4, a complete photometric and grism
calibration will be performed.
Basic NICMOS Parameters
Camera FoV Pixel scale ? coverage Capabilites Capabilites
NIC1 11x11 0.043 up to 1.9?m Polarimetry Diffraction limited for ?gt1.1?m
NIC2 19x19 0.075 up to 2.4?m Polarimetry Coronagraphy Diffraction limited for ?gt1.75?m
NIC3 51x51 0.2 up to 2.4?m Polarimetry Grisms