Commissioning Science Plan
FPRD Required Telescope Tests:
(From Instrument Acceptance Testing Plan)
- Field Size (all modes)
- Image Quality (all modes)
- Detector Pixel Scale (all modes)
- Flexure (all modes)
- Stray Light/Ghosts (all modes)
- Resolution (all spectroscopic modes)
- Efficiency (all modes)
- Instrumental Polarization (polarimetric modes)
Modes to be commissioned (from OCDD):
- Long Slit Spectroscopy
- Multi-Slit Spectroscopy
- High time resolution Long Slit Spectroscopy
- Fabry-Perot Imaging
- Long Slit Linear Spectropolarimetry
- Multi-Slit Linear Spectropolarimetry
Mode by mode description of potential science programs that would
fulfill commissioning requirements.
synopsis: narrowband imaging over 8 arcmin field; imaging in preparation
for multi-slit spectroscopic work.
- Quantify offsets and distortions between acquisition camera, guide probes,
- Test image quality over the field by observing a stellar field with known
astrometry and stellar sources.
- Calibrate filter set with standard stars.
- Test telescope pointing and tracking: produce plots of seeing and image
motion as a function of exposure time, hour angle, tracker position, and
- Test ADC by taking images of same field in different filters.
- Test non-sidereal tracking.
- Test shutter mechanism and check for timing errors.
Tests that will meet these goals:
- Measure Telescope Image Quality/Distortion:
Observe field with multitude of targets with known astrometry (see table
below). Compute image quality as a function of field.
Compute SALT/SAC/ADC distortion by undistorting PFIS astrometry via
PFIS distortion measured in ATP test 5.4. Test for various track geometries.
- Measure Guider Offset:
Observe field at set guider position. Measure astrometrically center of field
on PFIS image. Compute offset between measured center and tracker reported
position. Repeat for multiple guider positions. (on-sky)
- Measure Acquisition Camera Offset:
Observer field with PFIS and SALTICAM. Measure astrometrically center of field
on both PFIS and SALTICAM images. Compute offset between measured centers.
- Test Telescope Tracking: Measure image motion as a function of
exposure time, hour angle, tracker position, and rotator motion. This will need
to be decoupled from flexure (measured in PFIS ATP test 5.7). (on-sky)
- Linearity/Dynamic Range:
- Astrometric calibration:
|Field||RA (2000)||Dec (2000)||notes||Obs
|47 Tuc||00 24 05.2||-72 04 49||Globular cluster
|Omega Cen||03 26 45.8||-47 28 36||Globular cluster||Jul-Mar|
|LMC||05 11 00.0||-70 00 00||LMC bar/disk Smecker-Hane HST program||Aug-Mar|
|NGC 3603||11 15 09.1||-61 16 17||Young open cluster||Nov-Jul|
|M5||15 18 33.7||+02 04 58||Globular cluster (Cudworth astrometry)||Feb-Aug|
|M4||16 23 35.4||-26 31 32||Globular cluster
|NGC 6397||17 40 41.3||-53 40 25||Globular cluster (Cudworth astrometry)||Feb-Sep|
|M22||18 36 24.4||-23 54 12||Globular cluster (Cudworth astrometry)||Mar-Oct|
2. Long Slit Spectroscopy
synopsis: Conventional single long slit spectroscopy over full field at
arbitrary position angles. Used with the SALT ADC, parallactic angle
considerations do not restrict the position angle of the observation.
- Test use of standard long slits and target acquisition operations.
- Produce plots of spectrophotometric sensitivities with each grating.
- Produce plots of slit illumination function and image quality at several
different pupil illumination positions.
- Produce wavelength solution for each grating and how it varies with time,
tracker position, etc.
- Develop flatfielding techniques.
Tests that will meet these goals:
- Measure Effective Slit Width for Longslits: Using flat field measure
effective slit width and variation along the slit length for each longslit.
- Focus Acquisition Camera in Slitviewer Mode:
Insert longslit in PFIS focal plane. Observe field and determine best focus
for SALTICAM. (on-sky)
- Measure Wavelength Solution Stability: Using calibration system
and given grating position, measure wavelength solution for various tracks and
measure variations within a track. (on-sky)
- Measure Spectrophotometric Sensitivities of Gratings: For each
grating, choose finite set of camera/grating angles. Observe standard stars
and determine on-axis sensitivity. Test accuracy of interpolation for
intermediate angles. (on-sky)
- Spectroscopy of Standard Stars
- Galactic Superwinds:
- Observe edge-on galaxies with slit orthogonal to plane
- Measure velocities of emission lines
- Magellanic Cloud Supernova remnants/superbubbles (?)
2.1 Longslit Nod & Shuffle
3. Multi-Slit Spectroscopy
synopsis: Multi-object spectroscopy in fields up to 8x4 arcmin;
redshift surveys; spectral surveys of stars and galaxies.
- Test astrometric solutions and slitmask fabrication.
- Test slitmask insertion and position repeatability.
- Check for slitmask flexure with position, temperature.
- Test multi-slit acquisition strategy.
- Test multi-slit flatfields, spectral calibration.
- Plots of spectral senstivity versus field position for each grating.
- Plots of slit illumination function for "typical" slitmask (ideally a
standard mask used for calibration).
Test that will meet these goals:
- Measure Off-axis Blaze Shift:
- Multi-slit Calibration:
- Off-axis spectroscopy of standard stars (see Long-slit spectroscopy)
- Chemical abundances and kinematics of planetary nebulae in NGC 1399
3.1 Multi-slit Nod & Shuffle
4. High time resolution Long Slit Spectroscopy
synopsis: Time-resolved spectroscopy of cataclysmic variables, flares,
eclipses, AGN variability, gamma ray burst optical transients.
- Test data acquisition and storage under heavy throughput.
- Test use of CCD frame transfer mode.
- High-time resolution spectroscopy/spectropolarimetry of accretion columns
in highly magnetic CVs.
5. Fabry-Perot Imaging
synopsis: High resolution imaging spectroscopy of multiple or extended
objects; dynamical studies of HII regions, star clusters,
and galaxy clusters.
- Test etalon movement under full range of tracker motion.
- Test Fabry-Perot wavelength calibration.
- Measure FP efficiency.
- Intermediate-Redshift Galaxy Clusters
- Ca K 3933 line is redshifted into FP range between z=0.1 and z=1.187
- [O II] 3727 line is redshifted into FP range between z=0.15 and z=1.3
6. Long Slit Linear Spectropolarimetry
synopsis: spectropolarimetric studies of cataclysmic variables, young
stellar associations, stars with disks, AGNs, and interstellar absorption
- Test instrumental polarization as a function of field position.
- Test instrumental polarization as a function of pupil illumination.
- Verify waveplate mechanism performance.
|HD12021||8.86||01 57 56.11||-02 05 58.2||B7||0.112(0.025)||Jul-Jan|
|HD14069||9.00||02 16 45.16||+07 41 11.1||A0||0.111(0.036)||Jul-Jan|
|HD64299||10.15||07 52 25.55||-23 17 45.9||A2V||0.151(0.032)||Sep-Jun|
|HD94851||9.10||10 56 44.17||-20 39 51.6||B9||0.057(0.018)||Nov-Jul|
|HD98161||6.27||11 17 11.84||-38 0 52.0||A3V||0.017(0.006)||Nov-Jul|
|HD298383||9.68||09 22 29.76||-52 28 57.4||A0Ib||5.23||148.6||Oct-Jun|
|HD110984||8.95||12 46 44.91||-61 11 11.7||B0IV||5.7||91.6||Dec-Aug|
|HD111579||9.50||12 51 03.61||-61 14 37.8||B2Ib||6.46||103.1||Dec-Aug|
|HD126593||8.50||14 28 51.06||-60 32 24.8||B0.5IV||5.02||75.2||Jan-Sep|
|sigma Sco||4.57||16 20 38.20||-24 10 10.3||B5II||4.17||32.9||Feb-Sep|
|HD155197||9.20||17 10 15.62||-04 50 03.1||A0||4.38||103.2||Feb-Sep|
7. Multi-Slit Linear Spectropolarimetry
synopsis: Multi-object linear spectropolarimetry in fields up to 4x4
arcmin; polarimetric surveys.
- Circumstellar Disks in LMC/SMC clusters: Requires low-resolution, full
wavelength span - G0900 in blue and red tilts.
- NGC 1818 (LMC)
- NGC 330 (SMC)
7.1 Multi-Object Polarimetric Imaging