The Prime Focus Imaging Spectrograph for the The Prime Focus Imaging Spectrograph for the Southern African Large Telescope: Southern African Large Telescope:

Operational ModesOperational Modes

Chip Kobulnicky – Instrument Scientist, University of Wisconsin

PFIS Team

Kenneth Nordsieck PI – University of WisconsinEric Burgh Instrument Scientist – University of WisconsinDarragh O’Donoghue Detector PI - South African Astrophysical ObservatoryMichael Smith Instrument Engineer – University of WisconsinJeffrey Percival Project Manager – University of WisconsinTed Williams Fabry-Perot PI – Rutgers University

PFIS OverviewPFIS Overview

First-generation, all-purpose First-generation, all-purpose spectrograph on the Southern African spectrograph on the Southern African Large Telescope (SALT). Large Telescope (SALT). Commissioning in fall 2004. Commissioning in fall 2004.

Optical imaging spectrograph Optical imaging spectrograph

3200Å - 9000Å3200Å - 9000Å 8’ Field of view8’ Field of view All-refractive collimator & cameraAll-refractive collimator & camera

(see 4841-164, Burgh et al., for (see 4841-164, Burgh et al., for

optical design of PFIS)optical design of PFIS)

PFIS SchematicSubsystems: 1. Focal Plane

openlongslit custom slitmask

2. Polarization Opticsopen (quartz block)½ wave plate¼ wave plate½ & ¼ wave plates

+ polarizing beamsplitter 3. Dispersive Elements

none (unarticulated)5 VPH gratingsFabry-Perot etalon(s)

4. CCD Detectornormal readoutframe transfercharge shuffle

Planned Future Upgrade

PFIS Operational ModesPFIS Operational Modes

ImagingImaging Grating SpectroscopyGrating Spectroscopy

CCD Readout CCD Readout ModeMode

Observing ModeObserving ModeFocalFocalPlane Plane UnitUnit

Field

Field

Waveplat

Waveplat

Observing ModeObserving ModeFocalFocalPlane Plane UnitUnit

Field

Field

Waveplat

Waveplat

Normal Normal ReadoutReadout

(<0.25 Hz)(<0.25 Hz)

Filter ImagingFilter Imaging nonenone 8’8’ NN Longslit SpectroscopyLongslit Spectroscopy slits 1-6slits 1-6 8’8’ NN

Fabry-Perot ImagingFabry-Perot Imaging nonenone 8’8’ NN Multi-slit SpectroscopyMulti-slit Spectroscopy maskmask 8’8’ NN

Imaging PolarimetryImaging Polarimetry Mask 2Mask 2 4’4’ YY Longslit SpectropolarimetryLongslit Spectropolarimetry slit 7slit 7 4’4’ YY

Fabry-Perot PolarimetryFabry-Perot Polarimetry Mask 2Mask 2 4’4’ YY Multi-slit SpectropolarimetryMulti-slit Spectropolarimetry maskmask 4’4’ YY

Frame TransferFrame Transfer(fast; ~1 Hz)(fast; ~1 Hz)

Fast Filter ImagingFast Filter Imaging Mask 1Mask 1 4’4’ NN Fast longslit SpectroscopyFast longslit Spectroscopy slit 8slit 8 4’4’ NN

Fast Fabry-Perot ImagingFast Fabry-Perot Imaging Mask 1Mask 1 4’4’ NN Fast multi-slit SpectroscopyFast multi-slit Spectroscopy maskmask 4’4’ NN

Fast Imaging PolarimetryFast Imaging Polarimetry -- -- -- Fast Longslit Polarimetry Fast Longslit Polarimetry -- -- --

Fast Fabry-Perot PolarimetryFast Fabry-Perot Polarimetry -- -- -- Fast Longslit SpectropolarimetryFast Longslit Spectropolarimetry -- -- --

Charge ShuffleCharge Shuffle(very fast;(very fast;

up to 20 Hz)up to 20 Hz)

V. Fast Filter ImagingV. Fast Filter Imaging maskmask ”” NN V. Fast Longslit Spectroscopy V. Fast Longslit Spectroscopy slits 1-8slits 1-8 ”” NN

V. Fast Fabry-Perot ImagingV. Fast Fabry-Perot Imaging maskmask ”” NN V. Fast Multi-slit SpectroscopyV. Fast Multi-slit Spectroscopy maskmask ”” NN

V. Fast Imaging PolarimetryV. Fast Imaging Polarimetry maskmask ”” YY V. Fast Longslit Spectropolar.V. Fast Longslit Spectropolar. slit 7slit 7 ”” YY

V. Fast Fabry-Perot PolarimetryV. Fast Fabry-Perot Polarimetry maskmask ”” YY V. Fast Multi-slit Spectropolar.V. Fast Multi-slit Spectropolar. maskmask ””

Y Y

Forbidden modes

λλ Coverage & Spectral Resolution Coverage & Spectral Resolution

Contours at 90%, 70%, 50% efficiency. Assumes 1.25” slit, αmax=45 deg

4500

1500

3000R

Redshift surveysNebular abundances

Planetary nebulakinematics & abundances

Ca H&K, [O II] kinematicsz = 1.6 Ly αz = 1-2 restframe UVBowen florescence

Ca II stellar kinematics

1.2” seeing

0.7” seeing

Spectral Resolution vs. ThroughputSpectral Resolution vs. Throughput

780 l/mm VPH grating: efficiency and 780 l/mm VPH grating: efficiency and wavelength coveragewavelength coverage

Field center

-2’ field angle

+2’ field angle

Readout Modes and TimesReadout Modes and Times

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

Image Height(arcmin)

Image Height(pixels)

Readout Time(s)

4.0 2048 1.595

2.0 1024 0.797

0.5 256 0.199

0.125 64 0.050

2048 2048 2048

Image field4’

Charge transfer buffer

See 4841-052, O’Donoghue et al. for detector details

High Time Resolution

Fabry-Perot SpectroscopyFabry-Perot Spectroscopy

3 F-P Etalons3 F-P Etalons R=500 tunable filterR=500 tunable filter R=2500 (dual etalon)R=2500 (dual etalon) R=12000 (dual etalon)R=12000 (dual etalon)

4300 4300 ÅÅ – 8600 – 8600 ÅÅ

Star cluster kinematics Star cluster kinematics Galaxy cluster kinematics (z>0.4)Galaxy cluster kinematics (z>0.4)Flows in SF regions & galaxiesFlows in SF regions & galaxiesF-P imaging polarimetry of reflection nebulaeF-P imaging polarimetry of reflection nebulae

(PI - Ted Williams, Rutgers)

PolarimetryPolarimetry(See 4843-24 - Nordsieck et al.)

Linear polarimetry – ½ wave plate, 8 positions Imaging polarimetry, 4’ FOV – polarimetric surveysLongslit 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)

2048 2048 2048

40964’

mask

mask

Focal Plane Detector

PFIS Science & SummaryPFIS Science & Summary

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Rap

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Pola

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Fab

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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

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Signal-to-noise vs. Signal-to-noise vs. MagnitudeMagnitude

EfficiencyEfficiency

Spectral Resolution vs. ThroughputSpectral Resolution vs. Throughput