AURA New Initiatives Office S.C. Barden, M. Liang, K.H. Hinkle, C.F.W. Harmer, R.R. Joyce (NOAO/NIO) September 17, 2001 Instrumentation Concepts for the 30-meter GSMT

AURA New Initiatives Office GSMT Point Design Instrument Study Develop telescope, AO and instruments as an integrated system Design concepts driven by science objectives – Multi-Object, Multi-Fiber, Optical Spectrograph MOMFOS (science: tomography of the universe) – Near IR Deployable Integral Field Spectrograph NIRDIF (science: tomography of pre-galaxy fragments) – Mid-IR, High Dispersion, AO Spectrograph MIHDAS (science: origins of planetary systems) – MCAO-fed near-IR imager (science: stellar populations) Build on extant concepts where possible Define major design challenges Identify needed technologies

AURA New Initiatives Office Multi-Object Multi-Fiber Optical Spectrograph (MOMFOS) 20 arc-minute field at f/1 Prime Focus 60-meter fiber cable ” fibers 3 spectrographs, ~230 fibers each VPH gratings Articulated collimator for different resolution regimes Resolution Example ranges with single grating R= 1, nm – 650nm R= 5, nm – 530nm R= 18, nm – 508nm Detects 13% - 23% of photons hitting the 30m

AURA New Initiatives Office Prime Focus MOMFOS

AURA New Initiatives Office MOMFOS with Prime Focus Corrector Conceptual design fits in a 3m dia by 5m long cylinder

AURA New Initiatives Office MOMFOS Spectrograph Micro-Lens Relay 500  m diameter fiber fed by two micro-lenses with spherical surfaces. 100% of light couples into fiber. Field stop limits light to 0.72” aperture. Comparable lens required at fiber output.

AURA New Initiatives Office MOMFOS Spectrograph Fiber Positioner Positioner based on Echidna positioner built by AAO for FMOS on Suburu Echidna prototype image from

AURA New Initiatives Office MOMFOS Spectrograph R=18000 mode R=5000 mode R=1000 mode 500mm pupil; all spherical optics 4K by 4K CCD 15  m pixels 2 pixel binning 3 Spectrographs 230 fibers each 10 VPH gratings to cover full optical range and 3 resolution modes. f/4.5 Collimator f/0.86 Camera Articulated collimator

AURA New Initiatives Office MOMFOS Spectrograph Predicted Efficiency

AURA New Initiatives Office Spot Diagrams for MOMFOS Spectrograph R = l/mm nm 28.6° On-Axis Half-Field Full-Field Fiber Diameter

AURA New Initiatives Office Tomography of Individual Galaxies out to z ~3 GSMT 3 hour, 3  limit at R=5, ”x0.1” IFU pixel (sub-kpc scale structures) J H K

AURA New Initiatives Office Near Infra-Red Deployable Integral Field Spectrograph (NIRDIF) MCAO fed 1.5 to 2.0 arc-minute FOV 1 – 2.5  m wavelength coverage Deployable IFU units 1.5 arc-second FOV per IFU probe 31 slices per IFU probe (0.048” per slice) ~26 deployable units

AURA New Initiatives Office Near Infra-Red Deployable Integral Field Spectrograph (NIRDIF) Relay optics contained in deployable arm. 1.5 by 1.5 arc-second field of view. f/38 to f/128 converter from MCAO field to image slicer. Telecentric input and output. Cold stop located within relay.

AURA New Initiatives Office Near Infra-Red Deployable Integral Field Spectrograph (NIRDIF) f/128 image slicer with 31 slices converted to f/11.5 for the spectrograph. Spectrographs 2 IFU’s per spectrograph ~13 spectrographs R = 1000 to 10,000 Z, J, H, and K spectral coverage 2 K detector format assumed

AURA New Initiatives Office Near Infra-Red Deployable Integral Field Spectrograph (NIRDIF) Image Relay Image Slicer Spectrograph Two Image Slicers per Spectrograph

AURA New Initiatives Office Near Infra-Red Deployable Integral Field Spectrograph (NIRDIF) Spot diagrams for NIRDIF spectrograph. Slice 1Slice 16 Slice 31

AURA New Initiatives Office Origins of Planetary Systems Goals: – Understand where and when planets form – Infer planetary architectures via observation of ‘gaps’ Measurements: Spectra of accreting PMS stars (R~10 5 ;  m) Key requirements: On axis, high Strehl AO; low emissivity

AURA New Initiatives Office Mid-Infrared High Dispersion AO Spectrograph (MIHDAS) Adaptive Secondary AO feed On-Axis, Narrow Field/Point Source R=120,000 3 spectrographs 2-5  m (small beamed, x-dispersed), 0.2 arc-second slit length  m (x-dispersed), 1 arc-second slit  m (x-dispersed), 1 arc-second slit  m spectrograph likely to utilize same collimator as  m instrument. Different Gratings and Camera. 2-5  m spectrograph may require additional AO mirrors.

AURA New Initiatives Office Mid-Infrared High Dispersion AO Spectrograph (MIHDAS) mm spectrograph will be large. Diffraction limit at 20 microns is about ¼ arc-second, comparable to native seeing limit. Overall Echelle grating is 1.5 meters in length! Overall instrument is expected to take up a volume of about 4 by 2 by 3 meters! All of which needs to be cryogenically cooled. Instrument to be located at Cass location and move with the telescope.

AURA New Initiatives Office Mid-Infrared High Dispersion AO Spectrograph (MIHDAS) 1K by 1K Si:As detector 27  m pixels 150 mm by 1500 mm R10 (84°) Echelle 7 mm/line (0.143 l/mm) f/18.75 Collimator f/2 Camera 4-mirror camera Off-axis parabolic collimator 360 mm diameter cross-disperser 45 l/mm, 26.5° blaze

AURA New Initiatives Office MCAO Near-IR Imager f/38 input with 1:1 reimaging optics 1.5 to 2 arc-minute field of view Monolithic imager -  5.5 mm/arc-second plate scale!  arc-second per pixel sampling  685 mm sized detector array for 2 arc-min field!  28K by 28K detector!  7 by 7 mosaic of 4K arrays Alternative approach is to have deployable capability for imaging over a subset of the total field.

AURA New Initiatives Office Instrument Locations on Telescope MCAO-fed NIRDIF or MCAO Imager Cass-fed MIHDAS Fiber-fed MOMFOS

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