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Chip Kobulnicky – Instrument Scientist, University of Wisconsin PFIS Team Kenneth Nordsieck PI – University of Wisconsin Eric Burgh Instrument Scientist – University of Wisconsin Darragh O’Donoghue Detector PI - South African Astrophysical Observatory
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Chip Kobulnicky – Instrument Scientist, University of Wisconsin PFIS Team Kenneth Nordsieck PI – University of Wisconsin Eric Burgh Instrument Scientist – University of Wisconsin Darragh O’Donoghue Detector PI - South African Astrophysical Observatory Michael Smith Instrument Engineer – University of Wisconsin Jeffrey Percival Project Manager – University of Wisconsin Ted Williams Fabry-Perot PI – Rutgers University The Prime Focus Imaging Spectrograph for the Southern African Large Telescope: Operational Modes
PFIS Overview • First-generation, all-purpose spectrograph on the Southern African Large Telescope (SALT). Commissioning in fall 2004. Optical imaging spectrograph 3200Å - 9000Å • 8’ Field of view • All-refractive collimator & camera (see 4841-164, Burgh et al., for optical design of PFIS)
PFIS Schematic Subsystems: 1. Focal Plane open longslit custom slitmask 2. Polarization Optics open (quartz block) ½ wave plate ¼ wave plate ½ & ¼ wave plates + polarizing beamsplitter 3. Dispersive Elements none (unarticulated) 5 VPH gratings Fabry-Perot etalon(s) 4. CCD Detector normal readout frame transfer charge shuffle Planned Future Upgrade
PFIS Operational Modes Forbidden modes
λ Coverage & Spectral Resolution 4500 R 3000 1500 Contours at 90%, 70%, 50% efficiency. Assumes 1.25” slit, αmax=45 deg Ca H&K, [O II] kinematics z = 1.6 Ly α z = 1-2 restframe UV Bowen florescence Planetary nebula kinematics & abundances Ca II stellar kinematics Redshift surveys Nebular abundances
Spectral Resolution vs. Throughput 0.7” seeing 1.2” seeing
780 l/mm VPH grating: efficiency and wavelength coverage -2’ field angle Field center +2’ field angle
Readout Modes and Times 2048 2048 2048 Image field 4’ Normal readouts: 4096 x 6044 pixels – 3.6 s with 5e- read noise Frame Transfer: 2048 x 6044 pixels – 1.8 s with 5 e- readnoise Charge transfer buffer High Time Resolution See 4841-052, O’Donoghue et al. for detector details
Fabry-Perot Spectroscopy (PI - Ted Williams, Rutgers) • 3 F-P Etalons • R=500 tunable filter • R=2500 (dual etalon) • R=12000 (dual etalon) 4300 Å – 8600 Å Star cluster kinematics Galaxy cluster kinematics (z>0.4) Flows in SF regions & galaxies F-P imaging polarimetry of reflection nebulae
Polarimetry (See 4843-24 - Nordsieck et al.) Linear polarimetry – ½ wave plate, 8 positions Imaging polarimetry, 4’ FOV – polarimetric surveys Longslit spectropolarimetry – novae, magnetic stars, AGN Time-resolved polarimetry or spectropolarimetry – accreting binaries, AGN, GRB Circular polarimetry – ½ wave plate (8 positions), ¼ wave plates (2 positions) Focal Plane Detector 2048 2048 2048 mask 4’ 4096 mask
PFIS Science & Summary Polarimetry Fabry-Perot Multi-object Rapid Readout Multi-slit spectral surveys (e.g., redshift surveys, stellar surveys) X Wide-field polarimetric imaging (e.g., Magellanic Cloud surveys) X Extreme blue λ galaxy kinematics & populations (z=1-2) X High time resolution spectroscopy (CVs, GRB, AGN) X High time resolution spectropolarimetry (CVs, GRB, AGN) X X Imaging spectropolarimetry (novae, PNe, active galaxies) X X ?????