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Keck Instruments

Keck Instruments. The WMKO Support Astronomer Group. General. New SA: Scott Dahm from Caltech FY08 upgrades slowed by unfilled 8 th SA position. Instrument teams continue to provide excellent support. Web-based documentation: Observer manuals; throughputs or S/N calculators

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Keck Instruments

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  1. Keck Instruments The WMKO Support Astronomer Group

  2. General • New SA: Scott Dahm from Caltech • FY08 upgrades slowed by unfilled 8th SA position. • Instrument teams continue to provide excellent support. • Web-based documentation:Observer manuals; throughputs or S/N calculators • Electronic Observers’ NewsletterPositive feedback

  3. The Observing Experience • New “desktop”: FVWM • OpenLook no longer supported by Sun • ssh on all computers • VNC integration • RemOps I noise reduction • Simultaneous DVD writing • Better chairs • Scanners available.

  4. Instrument Masters

  5. NIRSPEC Jim Lyke

  6. NIRSPEC • From last year’s presentation: • Rotator-echelle interaction (no action) • Faulty SLIT init switch (now working) • Server crashes (fiber issues) • Bad SCAM quadrant • Warm & pump instead of window replacement • MAGIQ • New this year: • Noise investigation (Tom Greene visit) • Documentation update team identified • News is up-to-date

  7. Camera head Fold mirror Focus stage Dewar window Filter wheels NIRSPEC MAGIQ • MAGIQ camera installed and running every night • IQM not implemented (eng time on May 17) • Performance good, numbers after eng time • Some software & procedural issues

  8. NIRSPEC Bad SCAM • Bad SCAM quadrant • Reads all 0s • Affects all slits • User-defined nods • Do we try to fix? • Warm & pump fall 2008 • Similar problem prior to delivery • Nothing changed • “Fixed” by thermal cycle

  9. NIRSPEC Noise Plot of single rows • Noise Investigation • Tom Greene visit Apr 2008 • Digital (white plot) • Replaced bad A/D • Analog (red plot) • Left-side, 1 in 8 rows • Cooling? Grounding? • No read noise change • CDS: 50-55 e- • MCDS (16): 12-15 e-

  10. Window replacement + 3 months Warm & pump + 12 months (current) 3.45 mm 3.10 mm 2.65 mm NIRSPEC Ice Next warm & pump requested for fall 2008

  11. OSIRIS Jim Lyke

  12. OSIRIS • From last year’s presentation: • Efficiency (FOV & Acq.) – cookbook available • New this year: • March 2008 Service • Observers really like NIRC2/OSIRIS switching • Manual & web pages update

  13. Stage limit August 2007 OSIRIS Service • March 2008 Service • Add’l K-band filters w/ pupils for 100 mas • Removed redundant z-band filters • Fixed handling cart issue • Eng time for pupil performance (June 5) • Software updates • GUIs, scripts, DRP (mostly for new filters) • Strong relationship w/ UCLA team

  14. OSIRIS • DRP • Observers note slowness (45-60s per cube) • Users at Keck, UCLA, CIT, UCB • NIRC2/OSIRIS switching • Allows hi-res imaging/spectra in one night • Quick switch (no tertiary move) • Manual & web pages • New pupil performance data not available yet

  15. NIRC2 Al Conrad

  16. Outline • Differential Tracking with LGSAO. • More NIRC2 characterization on the web. • Proposed Service Mission.

  17. Differential Tracking with LGSAO • LGS-AO now allows differential motion between the tip-tilt reference and the laser guide star. • This mode allows use of an off-axis tip-tilt star for a nonsidereal science object. • First demonstrated with NIRC2 in mid-February (~30 mas rms jitter) • Successfully used for science in late March • Will be offered as a shared risk mode on future LGSAO nights (NIRC2 and OSIRIS). • “Vertical angle” mode coming soon.

  18. NIRC2 Characterization on the Web Astrometry page: • Recommended fields • PA accuracy • Dewarp tool. • Limiting rates and magnitudes for the 6 differential tracking modes. • A preliminary page for collecting JHK image quality comparisons from pre- and post-NGWFC.

  19. Proposed Service Mission • Status • Submitted as an FY09 project. • Not funded. Earliest date therefore Oct 2009. • AOWG comments will be solicited. • Summary of Proposed Changes • Filters • L-wide (to be acquired) • 8 others, including Y (in hand) • Polarimetry • Wollaston prism for NIRC2 filter wheel • Wave plate for the AO bench

  20. Service Mission Science Drivers • L filter will improve efficiency for both imaging and spectroscopy • Y-band filter will improve multi-color photometry studies of • low mass binaries • solar system objects. • Polarimetry • galactic center flares • structure and composition of circumstellar disks.

  21. LRIS Marc Kassis

  22. Performance and Upgrades • Overall, LRIS is performing well • Less than 4% of time lost to faults • Observer documentation updated end of last year • Software upgrades • Compass rose deployed for the Blue side • Focus procedures updated • Script configures LRIS, turns on appropriate lamps, and acquires images • Long slit focusing acquisition and analysis procedures available and documented

  23. Atmospheric Dispersion Corrector (ADC) • Released for routine observing in 2007B • Highly reliable operation; no nighttime faults encountered • Observer documentation was developed and published on web • Investigating a problem that puts ADC prisms into secondary limit during installation • ADC does not limit the precision of polarization measurements taken with LRISp • Using normal observing techniques • Analysis available on the web

  24. LRIS Broken I-Band Filter • Cancelled three LRIS nights • Metal to filter contact may result in chipping. • Filter chipped during 2006 earthquakes. • Crack propagated as filter rattled. • Shards jammed in grism mechanism

  25. Filter Repair • Filter particles found • In grism carousel • On three grisms and cells • Main LRIS compartment • Vacuumed filter and grism carousels and main LRIS compartment • Repaired chipped filters • 50% of red and blue filters had small chips at edges. • Ground out chipped areas • Taped filter edges • Used “First Contact” to clean optical surfaces

  26. Replacement filter • September 2007–queried LRIS observers about I-band filter replacement • Most observers preferred an I filter similar to Pan-STARRS i-band. • Z-band desired by community • I-band ordered from Barr Associates and will be delivered September 2008

  27. Hg, Zn, Cd lamps 1200/3400 grism Tint=10s ADUs Angstroms Fe/Ar lamp 1200/3400 grism Tint=30s ADUs Angstroms Calibration Lamps • Improve calibrations at 3000–4000 Angstroms • Install Fe/Ar and deuterium lamps for calibrating blue side • New lamp controller purchased • New lamp holder designed and being fabricated • Next step: test controller and new software in the lab

  28. Upgrade Slitmask Frames and Pickoff Mirrors • Goals • Improve mechanical reliability • Increase slitmask alignment efficiency • Slitmask frames redesigned • New bars to hold pickoff mirror designed • ME group will machine and assemble the frames and bars using Keck’s new CNC milling machine • Engineering with the prototype scheduled for May-June 2008

  29. SlitmaskPrototype • No screws • Pins in feet for reliable positioning • Slitmask curvature maintained by frame

  30. DEIMOS Greg Wirth

  31. DEIMOS Performance Notes • DEIMOS continues to perform well overall • Reflective coatings are in good condition • Faults averaged 3.9% over last year, relatively low • Grating system showing signs of wear • Clamp-up problems on slider 4 • Possible connection to FCS tracking failures • Low-level bias variations affect 2 of 8 science CCDs since earthquake; impact low

  32. Total lost time in last year was 21 hours Most grating loss was due to 1 major failure (6.5 hours) DEIMOS Time Loss May 2007 – April 2008 by source

  33. DEIMOS Improvements • Installed science-grade imaging flat • Milled new reflective variable longslit mask (5 slits w/ widths 0.7–1.5 arcsec) • Released custom arc-line plotting software tool for distribution • Published procedure for generating slitmask finder charts

  34. DEIMOS Future Priorities • Restore normal operation of grating system • Create combined longslit+focusing mask (free up 1 slitmask slot) • Troubleshoot CCD noise problem • Purchase replacement V filter (maybe)

  35. ESI Status Report Greg Wirth

  36. ESI Servicing Mission 2 • Prompted by May 2007 breakdown in imaging flat stage • Scope: • Repair broken coupling on imaging flat stage • Remove coating of titanium dust from optics • Machine shutter blades to reduce friction, dust • Troubleshoot collimator mirror actuators • Remove reflective optics for recoating • Job completed in Jul/Aug 2007 • Total ESI expenditures in FY07: • $67k from WMKO (incl. labor, materials, Lick contract) • $30k from UCO/Lick (donated labor and materials) • Instrument now working well again!

  37. ESI Optics • Key optics stripped and recoated with “Holy Grail” Ag-on-Al process at UCO/Lick • New coating has excellent reflectance • Decent longevity expected • Collimator substrate in poor condition; explains poor appearance of coating

  38. Scattered Light from ESI Collimator Scattering due to poor condition of mirror surface (not a coating problem)

  39. ESI Status • Recent usage shows small uptick: • 2007A: 14 nights scheduled • 2007B: 11 nights scheduled • 2008A: 16 nights scheduled • Recent developments: • Fixed broken air cylinder on shutter (other unit already replaced in servicing mission) • Recoated optics working well

  40. ESI Possible Future Actions • Complete commissioning of ESI Integral Field Unit (IFU) • Low demand for this mode • Requires 1-2 engineering nights • Request SSC guidance on the priority

  41. HIRES Grant Hill

  42. The past year has been a busy one for HIRES: • New Th/Ar lamp (original #1 died). • Better Argon/Neon balance. • Does not illuminate slit quite as fully. • HIRES electronics vault removed and much larger laser • enclosure put in place. • Repairs on aging mechanisms: • Optics covers Echelle stage motor control • Guider cooling Shutter • Oxygen sensor Shutter controller • Pneumatic actuators • Corrected software bug in corrector cover status • For several months, air purge desiccant was saturating • ~ weekly. HIRES Recent Work

  43. HIRES Current Issues • Gradients (<1%) in CCD biases. • Wavelength drifts at 1-2 pixel level (sporadic). • Runaway software process. • Humidity levels still being monitored. • Focus slowly relaxing towards pre-earthquake values • Optical coatings need monitoring. • Documentation. Remaining big items in order of priority: • Exposure time calculator. • Observers’ manual. • Echelle format simulator. • Th/Ar atlas/map. • Calibration advice. • Observing/post-observing checklists.

  44. Instrument PM Program Grant Hill

  45. FY08 includes resources to establish an instrument PM program. • We are not where we had hoped to be at this point though: • Mainly due to observatory resource shortages beyond • control of IPM team. • Somewhat under-resourced for FY08 to begin with. • But still some good news: • Work resuming on IPM project. • First draft of software requirements document written. • Compilation of PM task database begun. • Some PM’s are being done. • We are better resourced in FY09 than in FY08. Instrument PM Project

  46. Mainland Observing Gregory D. Wirth

  47. Supported sites: Caltech* LBNL* UCLA* UCSC* UCSD* UCB* (new) UCSB (new) UCR (new) Future sites: UCI (summer 2008) UCD (fall 2008) Caltech 2nd room UH-Manoa (maybe) *Specified sites support mainland-only observing mode Mainland Observing: Recent Developments

  48. Mainland Observing: Usage & Performance • Capabilities enhanced • Second set of ISDN backup lines installed • Enables mainland-only mode on both telescopes • Response improved • Summit→Mainland link now 1GB/s (>6x faster) • HQ→Summit link now 1GB/s (>20x faster) • Reliability outstanding • Internet outages rare last year • No observing time loss • Popularity increasing • Now used on ~1/3 of nights

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