Binospec Next Generation Optical Spectrograph for the MMT

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Binospec - Next Generation Optical Spectrograph
for the MMT

• Daniel Fabricant, Robert Fata, Mark Mueller, Jack
  Barberis, Tom Gauron, and John Roll

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Binospec at a Glance

• Dual beams address adjacent 8' by 15' fields of
  view (30' total slit length)
• 3900 to 10000 Å spectral coverage
• Spectral resolution 1300 5000 with 1? wide
  slit
• Sampling is 0.22?/pixel on 4K by 4K array

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Binospec vs. the World
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Scientific Drivers for Binospec

• Large scale structure and galaxy evolution
  from z0-1.4 with OII3727 and z2.2-7 with Ly a

Ly a at z5.8 5.5 hrs with DEIMOS 9 i dropouts
in 200 sq arcmin GOODS-N field
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New Scientific Possibilities with Binospec

• Perform slitless spectroscopy to identify PN in
  nearby galaxies and conduct dynamical studies
• Characterize faint Chandra/Spitzer AGN samples
  beyond reach of Hectospec
• Efficiently observe crowded fields that do not
  use 1º Hectospec format
• Carry out programs that require both imaging and
  spectroscopy. We could explore additional
  options opened by queue observing.

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Binospec Initial Grating Choices
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Binospec Imaging
FOV 15' by 16', use pair of 7 by 10 inch filters
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Binospec Optics
MMT f/5 focus
2.9 meters
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Binospec Layout
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Binospec Layout
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Binospec Image Quality
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Athermalized Optics
Coupling fluid lenses
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Binospec Lens Mounts
Flexure mounts instead of elastomeric mounts
materials compatible with coupling fluid and
greater control of axial stiffness
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Binospec Collimator Lens Cell
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Binospec CCDs
Current deep depletion E2V CCDs
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Active Flexure Control
512 x 2028 Flexure control CCD
Flexure control CCDs will monitor position of
fiducial fibers mounted on slit mask assembly.
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Active Flexure Control in Operation

• Grating tilt for wavelength setting will be
  controlled by the flexure control system
• Flexure and focus shifts will be removed by
  3-axis piezo stage in the dewar
• Flexure control system will have selectable lamps
  and a filter wheel to pass only the desired light
  for flexure control

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Binospec on its handling cart
Entrance window
Electronics boxes
CCD electronics
Cover/thermal shroud
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Changing Slit Masks, Filters and Gratings
Filter access
Slit mask access
Grating access
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Changing Filters and Gratings
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Binospec Bottom View
Grating exchange
Grating
Camera optics
Collimator optics
LN2 dewar
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Binospec Inverted
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Binospec Top View cover removed
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Binospec Focal Plane Area
Slit mask cassette
Center field acquisition and slit guider
Off-axis WFS
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Binospec Status

• Mechanical design nearing completion CDR fall
  2006. Electronics design is mature.
• 10/12 CaF2 lenses coated and delivered
• 6/6 aspheric lenses nearly complete
• Major assembly task of mounting lenses in bezels
  will be prototyped this summer.
• Delivery late 2008/early 2009