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Keck Instruments

Keck Instruments. The WMKO Support Astronomer Group. Introduction. Eight facility instruments Each instrument has an assigned “Master” and a “Secondary Master.” Summit instrument group provides “hands-on” assistance. (Dwight Chan and Mike Wagner)

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Keck Instruments

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  1. Keck Instruments The WMKO Support Astronomer Group

  2. Introduction • Eight facility instruments • Each instrument has an assigned “Master” and a “Secondary Master.” • Summit instrument group provides “hands-on” assistance. (Dwight Chan and Mike Wagner) • Summit crew does reconfigs, basic troubleshooting, etc. • Mainland observing update

  3. Organizational Changes • Summit instrument group reorganized and refocused. • Grant Hill acting as summit liaison • Significantly improved system!

  4. Instrument Masters

  5. LRIS Status Marc Kassis

  6. Recent LRIS Problems Addressed • Replaced the blue side shutter with spares (x2) • New parts machined • Spares refurbished by Caltech • Replaced damaged Blue side Dewar window • Replaced broken slitmask rollers after repeated mechanism jambs • Repaired offset guider encoder • Repaired slit viewing guider glycol leak • Replaced grating Compumotor and encoder

  7. Recent LRIS Improvements • Software • Released slitmask imaging tool • Released automated focus routines • Implemented long slit and polarimeter focusing routines • Hardware • upgraded limit switches for slitmask grabber and trapdoor to improve reliability • Documentation • Revamped LRIS web pages • Observers very pleased with updated content • Page style may change to further improve navigation and appearance

  8. Current LRIS Concerns • Blue and Red side shutters. • Blue shutter failure rate is 1.5 years • Red shutter does not have a good spare • Identifying possible solutions for replacement (Caltech involved) • Blue side CCD power drops (ongoing investigation) • Slitmask door mechanical problem; new latches planned • Grating port three homing problem; limit switches need adjustment • Blue side carousel flags prone to misalignment – more robust switches identified (Caltech involved)

  9. LRIS Optical Issues • Instrument focus dependent on rotation and elevation. • LRIS rotational center is offset from the telescope’s mechanical and optical axis by 1.5 in • This affects image quality detrimentally K1+ f/15 LRIS The K1+f/15 center of rotation is marked by black theodolite cross hairs while yellow fishing line marks the center of the LRIS optical axis.Photo taken during ADC alignment by Drew Phillips.

  10. Fe/Ar lamp 1200/3400 grism Tint=30s counts 2900 3400 3900 Angstroms Future LRIS Upgrades • Hardware • Install Fe/Ar and deuterium lamps for calibrating blue side • Improve slitmask frames • Improve slitmask guides for better reliability • Software • Develop calibration GUIS similar to DEIMOS or HIRES • Expand FITS headers to include slitmask design and target information to aid slitmask alignment & data reduction • Replace FIGDISP with DS9 reliability

  11. LRIS Performance Monitoring • Released scripts that reconfigure the instrument and acquire throughput data • Completing LRIS mechanical checkouts prior to each observing run • Implemented software to check common detector parameters (gain, read noise, linearity).

  12. NIRC(a.k.a. NIRC classic) Marc Kassis

  13. Status of NIRC Classic • NIRC is rarely used • Six nights in 2006B • Four nights in 2007A • Following the earthquake • Guider was used as an emergency spare for the LRIS slit-viewing guider • Dewar was thermally cycled to address an image artifact (“flash light effect”)

  14. HIRES Grant Hill

  15. HIRES Recent Work • Semi-regular monitoring of detector characteristics begun, Feb. 06. • Replaced ion pump and oxygen-soaked mosaic, May 06. • Considerable progress on web pages. (Number of updated and activated pages more than doubled.) • Earthquake. • Installation of new comparison lamp begun (ongoing). • Review of spare inventory and purchases begun.

  16. HIRES Earthquake-induced focus change

  17. HIRES Current Issues • Further documentation and web pages improvements. • Likely to be a background effort over next year. • Goal is have manual rewritten by end of 2007. • Occasional reports of wavelength instability. • Investigations so far inconclusive. • Further experiments planned in April–June. • PM program. • PM program for all instruments proposed as an FY08 project. • Project will include predictive and preventative maintenance and performance monitoring. • Project proposal includes planning tool improvement/construction (e.g. exposure time calculator, echelle simulator, etc.)

  18. NIRSPEC Jim Lyke

  19. NIRSPEC • Anonymous user comments: “NIRSPEC works.” “SCAM is invaluable.” “I don’t trust the rotator.”

  20. NIRSPEC Recent Work • NIRSPAO is back! • Six nights in Dec. 2006, including first LGS-AO night. • Two nights in June 2007. • Cold heads replaced March 16, 2005 • 65,000 operating hours (7+ years) • Server improvements have eliminated most server crashes. • EFS now allows user-defined nods

  21. NIRSPEC Current Issues • Rotator slews move the echelle • Dispersion direction–not seen in low-res • Arc lines shift by 1 pixel • Re-emergence of an old problem; solved by replacing motor last time. • Slit primary init switch faulty • Server crashes • Rotator-caused crashes are gone • Dirty optical fibers for some • Mystery cause for others • SCAM intermittent quadrant • Ice on dewar window

  22. NIRSPEC Window Ice • Recurring problem (every 6–12 months) • Previously, replaced window • March experiment to just warm and pump dewar was successful

  23. NIRSPEC Ice absorption at 3.1 mm is gone Most recent: middle plot, green line Before After

  24. NIRSPEC • Upcoming Events • NIRSPEC’s 8th Birthday April 25, 2007 • 800+ science nights allocated • Possible service for rotator and slit • MAGIQ upgrade Fall 2007

  25. OSIRIS Jim Lyke

  26. OSIRIS Earthquake Damage Fully functional after repair 4 nights lost (switched to NIRC2)

  27. OSIRIS Current Issues • Small FOV • 0.32 x 1.28 arc sec • Relative astrometry vital! • Less sensitive • Calculation error • Grating efficiency • Not many papers • Data reduction difficult, but help is coming!

  28. OSIRIS Papers The rate of papers per night for OSIRIS, a year after commissioning, is similar to the rate for NIRSPEC, a year after it commissioned. * Engineering nights not included

  29. OSIRIS • DRP Issues • Distributed. • No mechanism to notify users of updates • New and different data products • No dedicated support • No Telluric Correction • Long integrations • Changing sky background

  30. OSIRIS Future • What’s Next? • Papers! • Breakthrough with telluric correction • Use background region to calculate sky • Many are working on techniques and tools • Larkin, Wright, McElwain (UCLA) • Team Keck (using Director’s nights—thanks, Taft!) • Perrin, Laver, Adamkovics (UCB) • Law (CIT)

  31. NIRC2 Al Conrad

  32. Galaxy 4C29.28 ER2 from “Identification and Morphologies of Galaxies with Old Stellar Populations at z 2.5” Alan Stockton and Elizabeth McGrath NIRC2 Recent Work • Cold since August 2003 • Use has broadened since LGSAO commissioned • LGS/NGS ratio approx. 3-to-1 • e.g., Faint Galaxies • Calibration lamps available • Use of pupil masks increasing

  33. NIRC2 one-second dark showing fixed pattern noise in lower left quadrant • Motor homing • Detector Noise NIRC2 Current Issues

  34. 2 data source types: Images of clusters and pin-holes NIRC2 Project: Astrometry Plate Scale Distortion Position Angle CLUSTER PINHOLE Goal: Better characterize PA, plate scale, & distortion Summary of Results: • Plate Scale: Fit residuals 0.06–0.09 pixels; 6–8 times more precise than preship values. • PA: Known to within 0.1 degrees; may improve with further analysis. • Pin-hole distortion: subpixel in the interior; 2–3 pixels at the edge.

  35. Report: by Brian Cameron (posted on the NIRC2 web page) NIRC2 Astrometry (cont.) Narrow camera Web Page for Astrometry Calibration: • Recommended fields and observing scripts. • Voluntary repository. • dewarp tool (written in IDL). Related work: Konopacky, Britton, Lu, others.

  36. DEIMOS Greg Wirth

  37. DEIMOS Recent Work • DEIMOS has been working very reliably with only minor problems • Slitmask system jammed due to re-use of old and warped masks (e.g. long slits); resolved by discarding certain old masks • Spurious rotator moves during mask alignments traced to missing DCS keywords; fixed by software patch • Grating moves sometimes failed due to misalignments; fixed by revising target position

  38. DEIMOS Current Issues • Pattern noise is present on 2 of 8 science CCDs since earthquake; troubleshooting a possible grounding problem • Slitmasks continue to generate dust that contaminates optics, but fix is costly

  39. DEIMOS Performance Monitoring • Basic mechanical and optical checkouts performed before each run • Coatings on collimator and tent mirror being inspected and measured bimonthly for condition and reflectance • Standard star throughput data being gathered monthly; analysis pending

  40. DEIMOS Future • Urgent • Resolve CCD noise problems • Performance Monitoring • Analyze throughput data • Clean optics and gratings • Automate monthly checkout procedures • If time permits • Commission ultrasonic slitmask cleaner • Purchase replacement clear, V filters to replace damaged ones • Install science-grade imaging mirror

  41. ESI Greg Wirth

  42. ESI Recent Problems • Bearing failed in middle wheel of triple-wheel assembly; UCO/Lick replaced all 6 bearings in system • Belt drive system for triple wheel has broken several times; UCO/Lick has redesigned system to improve reliability • Optical encoders on triple wheels prone to signal loss; serviced and aligned units

  43. ESI Current Issues • Optical coupling fluid leaked onto shutter and camera optics, but has not seriously impacted observing • ESI host computer is obsolete and unreliable; UCO/Lick is helping us convert to new host computer • Collimator coating is in poor condition; needs recoating • Collimator actuator #1 fails some moves, troubleshooting in progress • Coupling to slitmask wheel is marginal, requires replacing • Flexure characteristics were rechecked and are consistent with results at commissioning

  44. ESI Future • Urgent • Mitigate optical coupling fluid contamination • Improve triple-wheel encoder alignment • Troubleshoot failed collimator moves • Replace slitmask wheel coupling • Investigate coating options for collimator • If time allows • Upgrade host computer for maintainability • Replace FIGDISP with ds9 image display tool • Begin program of regular throughput monitoring

  45. Mainland Observing Greg WirthBob Kibrick

  46. Mainland Observing Background • Goal: to provide observers at mainland sites the same capabilities as in Waimea • Strategy: employ VNC software to permit sharing of desktops between observers at mainland sites and Waimea • Benefit: provides observers flexibility, e.g. to take advantage of give-back science nights, deal with personal crises, possible time-domain astronomy

  47. Mainland Observing Status • System stable and reliable with near-zero downtime • Sites: Caltech, LBNL, UCSC, UCLA, UCSD • Instruments: all supported except IF • Usage: 142 nights since 2006A • Modes of operation: • Shared mainland and Waimea operation (84%) • Mainland-only operation (14%) • Video-only (2%)

  48. Mainland Observing Usage by Instrument* * usage since 2006A

  49. Mainland Observing Usage by Site* * usage since 2006A

  50. Mainland Observing Issues • Backup lines: currently providing ISDN backup to only one site per night (limits us to only one telescope per night) • Conflicts: limited to one observing team per site • Performance: slightly slower under VNC compared to normal Waimea operation • Operation: LBNL site not yet compliant • Lacks router for ISDN backup lines • Provided computers not yet compliant

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