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Summary of Instrument Feasibility Study Phase SAC, Apr 14, 2006

Summary of Instrument Feasibility Study Phase SAC, Apr 14, 2006. Crampton, with input from Simard, Ellerbroek, Sanders, Silva. . Outline. Recap of instrumentation process How we got here Top level outcomes from reviews Details on instruments and their reviews SRD requirements

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Summary of Instrument Feasibility Study Phase SAC, Apr 14, 2006

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  1. Summary of Instrument Feasibility Study PhaseSAC, Apr 14, 2006 Crampton, with input from Simard, Ellerbroek, Sanders, Silva TMT.INS.PRE.06.034.DRF01

  2. Outline • Recap of instrumentation process • How we got here • Top level outcomes from reviews • Details on instruments and their reviews • SRD requirements • Instrument teams, review panels • Results from studies and reviews • Updated costs • Proposals for SAC participation • Schedule • Options Many of these slides are meant to be info for SAC; they will not be discussed - only slides with a  will be. If you’d like additional info, use the discussion tool here:http://project.tmt.org:8080/docushare/dsweb/View/Collection-136 TMT.INS.PRE.06.034.DRF01

  3. Top-level: How we got here • Original plan (2004 Nov) • Competitive studies for all instruments during feasibility study phase • Studies intended to influence science cases and bring new instrument ideas • True conceptual design studies for top priority “first light” instruments • ideally still all competitive during conceptual phase • Apr 2005: results from RFP competition • Three collaborative studies emerged, and only two truly competitive studies • NFIRAOS (HIA) plus Project staff • IRIS (UCLA and Caltech) • MIRES (NOAO and U Hawaii) • WFOS (HIA) and GLAO plus a “MILES costing study” at Caltech • PFI (LLNL, JPL, U de Montreal) • HROS: 2 studies - UCSC and U Colorado • IRMOS: 2 studies - U Florida and Caltech plus MOAO at UCSC • Feasibility Study Reports • Feb 15 2006 • Face to face reviews in early March • Still waiting for reports from some review committees TMT.INS.PRE.06.034.DRF01

  4. Feasibility Study Reviews • Reviewed predominantly by “instrumentalists” • Who were external to TMT • External perspectives, different experiences • Who are recognized as experts in 8-10m and ELT instrumentation. • Quickly identified problem areas, offered alternative solutions or advice • The expectation is that SAC will review the science cases • The project will evaluate review reports and new SAC input • The project will take a stronger role in revising the proposed instrument goals, combining input above with cost, technology readiness and team strength issues TMT.INS.PRE.06.034.DRF01

  5. SAC Reading Material(http://project.tmt.org:8080/docushare/dsweb/View/Collection-1506) • Feasibility Study Reports (very detailed) • Observing Scenarios (“OCDDs”) : • sensitivity and time estimates for science programs, etc. • Reports from external Review Panels • SAC members should read ALL of them (very, very informative and not a big reading load). IMPORTANT: Both the feasibility reports and the OCDDs contain greatly expanded science cases (with respect to the original TMT Detailed Science Case) that SAC should read and discuss.

  6. Feasibility Study Reviews:Two Overarching Comments • Review panels frequently advocated reexamining SRD requirements • Panels did not understand why Project took them so literally. • Technical implications of current SRD requirements on size and complexity (examples: cooled NFIRAOS, very large WFOS, ) have now been demonstrated • Better justification of crucial SRD requirements (e.g., image quality, emissivity, FOVs) strongly encouraged. • Review panels frequently concerned about “systems” issues: • Aggressive requirements (e.g.,high contrast imaging, FOV) must be supported by TMT systems (optics, structure, AO) in the presence of perturbations (wind, vibrations, flexure, etc. etc.) - integrated modelling is strongly encouraged

  7. SAC Input needed Based on feasibility studies reports and external review panel recommendations, SAC should: • Reexamine SRD and desired scientific capabilities, instrument specs and priorities • To be done with putting appropriate weight on technical implications and operational impact • Reexamine instrument concepts • Do current instruments still make sense or are modified/new ones needed? • Provide revised and detailed requirements for the next phase of AO/instrument development The project instrumentation team is independently reassessing results, and the project will use this and SAC input to define a revised program

  8. Definitions • First light instrument = day 1 instrument, used for commissioning • First generation = first 3-5 years • Highest priority instruments that fit within budgetary envelope, have a high likelihood of being ready, and are consistent with overall observatory plans. • Funded from TMT construction budget (+ instrument associates and donors) • First decade = first 10 years = total suite of instruments • Some development and long-lead items could come from construction funds; majority of funding from ops budget, associates, etc TMT.INS.PRE.06.034.DRF01

  9. Individual Instruments • In the following slides, for each SRD instrument: • SRD requirements • Study and review teams • Study highlights • Highlights from review • Questions for SAC highlighted in red • Project perspectives interjected in blue TMT.INS.PRE.06.034.DRF01

  10. PFI SRD Planet Formation Imager • 1-2.5µm, goal 1-5µm • Field of view 0.03-1 arcsec radius • Image quality/contrast • Detect planet at 106 contrast or 107 goal for 1st generation system • Suitable coronagraph • Optical system should not preclude 108 contrast in H band for R<8 mag • Critically sampled at 1µm (0.0035 arcsec pixels) • Spectral resolution ≤ 100 TMT.INS.PRE.06.034.DRF01

  11. PFI Study and Review • PFI Study: • Joint study by LLNL, JPL, U de Montreal, led by Bruce Macintosh, Mitch Troy and Rene Doyon • Review Chair: Doug Simons, Gemini • Reviewers (substantial overlap with Gemini ExAOC review panel) • Niranjan Thatte, Oxford (VLT SINFONI, JWST) • Olivier Guyon, Subaru (AO, high contrast imaging) • Wes Traub, JPL (TPF) • Peter Hastings, UKATC (Mechanical design) • Bernard Delabre, ESO (Optical design) • Hilton Lewis, Keck (Instrumentation, SW) • Eli Atad, UKATC (Optical design) TMT.INS.PRE.06.034.DRF01

  12. PFI Feasibility Study Results • Science: • Much more compelling science case than previously envisioned • Less competition from space • Technical • Builds on Gemini Planet Imager (“GPI”) study • Tremendous support from JPL and LLNL • Extremely important interaction with telescope optics (led by Mitch Troy) • Cost and schedule • $38.2M including 30%contingency • Probably better estimate than average due to GPI study • $15M is “AO” budget • Could be completed late in 2014 if started 2009 Jan 1 • Only 2 year build phase: seems optimistic to me • Phasing would allow input from GPI • March 2008 Final design Review for GPI • October 2010 GPI complete TMT.INS.PRE.06.034.DRF01

  13. PFI Feasibility Study Results • Science: • Much more compelling science case than previously • Less competition from space • Technical • Builds on Gemini Planet Imager (“GPI”) study • Tremendous support from JPL • Extremely important interaction with telescope optics (led by Mitch Troy) • Cost and schedule • $38.2M including 30%contingency • Probably better estimate than average due to GPI study • Could be completed late in 2014 if started 2009 Jan 1 • Only 2 year build phase: seems optimistic to me • Phasing would allow input from GPI • March 2008 Final design Review • October 2010 GPI complete TMT.INS.PRE.06.034.DRF01

  14. PFI Review Committee Comments • Science • Compelling science in “untapped parameter space” • Advocate that focus be on complementary science to GPI and VLT/PF • being mindful that 10-8 contrast may not be reached • Technical • Several unproven (even in lab!) subsystems => schedule risk • Alignment will be challenging => cost and schedule risk • Uncertainties in telescope performance => large uncertainty in PFI performance => performance risk • Very concerned about telescope performance • Ghosts, scattering, dust may also affect performance • Optimization for smaller IWA most important? TMT unique • Once again, may not achieve better contrast than 8m but should achieve smaller separations. • Suggest dropping 3-5mu goal (emissivity too high) TMT.INS.PRE.06.034.DRF01

  15. IRIS SRDInfrared Imaging Spectrograph Integral Field Spectrograph and Imager working at the diffraction limit • Fed by NFIRAOS (Narrow field facility AO System) • Wavelength range: 0.8-2.5µm; goal 0.6-5µm • Field of view: < 2 arcsec for IFU, up to 10” for imaging mode • Spatial sampling: 4 mas per pixel (Nyquist sampled (/2D)) over 4096 pixels for IFU); over 10x10 arcsec for imaging • Plate scale adjustable 0.004, 0.009, 0.022, 0.050 arcsec/pixel • 128x128 spatial pixels with small ( ≤ 0.05) wavelength coverage • Spectral resolution • R=4000 over entire J, H, K, L bands, one band at a time • R=2-50 for imaging mode • Parallel imaging: goal TMT.INS.PRE.06.034.DRF01

  16. IRIS Study & Review • IRIS Study: • Joint study by UCLA(lenslet-based) and Caltech(slicer-based IFU) • Review Chair: Niranjan Thatte, Oxford (VLT SINFONI PI, AGN) • Reviewers • Jay Elias, NOAO (NFIRAOS interface) • Doug Simons, Gemini • Bernard Delabre, ESO (Optical design) • Keith Matthews, Caltech (IR instrumentation) • Peter Hastings, UKATC (Mechanical design) • Peter McGregor, ANU (Gemini NIFS, GSAOI) • Eli Atad, UKATC (Optical design) • Remote reviewers • Markus-Kissler Patig, ESO (SINFONI, KMOS, VIMOS, star clusters). • Eric James, Gemini (Mechanical design) TMT.INS.PRE.06.034.DRF01

  17. IRIS Feasibility StudyResults • Science (IRIS science team) • Field more important than wavelength bandpass • 5% bandpass adequate for most science (cf 20% SRD) • “simultaneous larger field more important than simultaneous broadband coverage” • No strong preference between slicer or lenslet IFU concept • Technical • Incomplete: • unable to downselect between slicer and IFU • slicer concept not developed • No concept for complete instrument presented TMT.INS.PRE.06.034.DRF01

  18. IRIS Feasibility StudyResults • Cost • $24M including 40% contingency • But no NGS wfs (add $3.2M) or ADCs • Presumably only for lenslet design, based on OSIRIS • Not entirely clear what functionality this provides • presumably four 2K*2K spectro detectors with up to 2” field and one 15”*15” imaging field • Schedule • Estimated 6 years to build, from conceptual design to integration/installation, I.e., could be ready by 2015 NFIRAOS first light if started January 2009 • But we need a better design with better cost and schedule estimates TMT.INS.PRE.06.034.DRF01

  19. IRIS Review Committee Comments • Science • Unconvinced about reduced wavelength bandpass • Unconvinced that very fine (4mas) sampling is required, or optimal, especially since NFIRAOS performance at 1mu won’t initially meet SRD • Science trade: • whether maintaining image quality within instrument is paramount (lenslet option better), • or whether more effective use of pixels (to improve field or bandpass) and better signal-to-noise are more important (advantage: slicer option) • my sense is that the panel leaned towards the latter • => More in-depth analysis of trades required, especially of optimal pixel scales, field sizes, wavelength coverage • Perhaps SAC would like to participate in this? TMT.INS.PRE.06.034.DRF01

  20. IRIS Review Committee Comments • “IRIS .. Can be built with existing technology to provide a top class, first light capability for TMT” • IRIS will be a workhorse instrument • Attractive “point-and-shoot” capability • Builds on current 8-10m heritage, notably OSIRIS, SINFONI, NIFS • Technical • Credible lenslet design presented • But, for several reasons, not clear whether it’s optimal • Insufficient detail presented for slicer option • Design of overall instrument (including WFS, ADCs, imagers, spectros) required • ADCs and WFS are biggest risk items since they have not been studied at all; IRIS per se is straightforward TMT.INS.PRE.06.034.DRF01

  21. NIRES SRDNear IR Echelle Spectrometer • Diffraction limited spectro, fed by NFIRAOS • Wavelength range: 1-5µm, simultaneous 1-2.4µm, 3.5-5µm • Subsequently divided by SAC into two instruments: “blue NIRES” behind NFIRAOS and a “red NIRES” behind MIRAO (or AM2) • Field of view of acquisition camera: 10 arcsec, 0.0035 arcsec/pixel • Slit length: 2 arcsec • Spatial sampling: Nyquist sampled (l/2D) • Spectral resolution: 20,000<R<100,000 TMT.INS.PRE.06.034.DRF01

  22. NIRES Study and Review • NIRES “mini-study” • Mini-study by UH(Rayner & Tokunaga) + NOAO(Elias) • Builds on heritage of Gemini HRNIRS, Keck NIRSPEC, VLT CRIRES • Review • Same team as for MIRES, chaired by Tom Geballe TMT.INS.PRE.06.034.DRF01

  23. NIRES mini-study results • Science case much improved • IGM z > 7, including GRBs • Local group abundances, including galactic centre • Abundances, chemistry and kinematics of stars and planet-forming disks • Detecting terrestrial planets around low-mass stars • Characterizing extra-solar planets and brown dwarfs • Technical • Split NIRES into two instruments, “bNIRES” and “rNIRES” • science requires highest R at longest wavelengths => long wavelength instrument ~10x size of short => very different instruments • bNIRES fed by NFIRAOS; rNIRES by MIRAO • bNIRES is relatively straightforward, small (and cheap) TMT.INS.PRE.06.034.DRF01

  24. NIRES mini-study results • bNIRES cost estimate • $11.3M including NGS WFS. • “Based on NIRSPEC cost, so contingency is presumed to be included” • rNIRES cost estimate • $14.0M including contingency • assuming MIRAO exists • Schedule • No schedule given - will try to find out TMT.INS.PRE.06.034.DRF01

  25. NIRES Review Committee Comments • Very little comment on NIRES, more focused on MIRES • Technical • Increase slit length => Increase detector size to two*4K • Radial velocity precision goals are very ambitious • Pay attention to scattered light in next phase • Incorporate rNIRES into MIRES, i.e., creating a “bMIRES” channel? SAC has already (Jan 06) agreed that NIRES should be split into two instruments and that rNIRES should be fed by MIRAO instead of NFIRAOS. What priorities do they have cf each other, and with other instruments? TMT.INS.PRE.06.034.DRF01

  26. MIRES SRD Mid-IR Echelle Spectrometer • Mid-IR Diffraction Limited Spectrometer, fed by MIRAO (AM2?) • 8-18µm, 5-28µm goal • FoV 10 arcsec • Slit length: 3 arcsec order separation, or IFU • Spatial sampling • 0.017x0.017 arcsec pixels • Spectral resolution • 5000< R <100000 with diffraction-limited slit • R=2-50 for imaging mode • Detector • 2000x2000 TMT.INS.PRE.06.034.DRF01

  27. MIRES Study and Review • Study • NOAO and UH teams merged, led by Jay Elias and Alan Tokunaga • Team includes John Carr, NRL and Matt Richter, UCDavis • Review Chair: Tom Geballe, Gemini (MIR instruments) • Reviewers • Sean Adkins, Keck • Francois Wildi, Switzerland (AO, adaptive secondaries) • Ulli Kaeufl, ESO (IR spectrographs) • Miska Lelouarn, ESO (AO modelling) • Remote reviewers • Bob Gehrz, Minnesota (IR instruments, Spitzer, JWST) • Colin Cunningham, UKATC (Instrumentation, ELT instrumentation) • Ian McLean, UCLA (IR spectrographs) TMT.INS.PRE.06.034.DRF01

  28. MIRES Study Results • Science case strengthened • Very strong science case for “planet-related studies” • Technical • R~100,000 mainly required • Costs • MIRAO: $13.6M including 65.5% contingency • includes DM and 5 array detectors • includes upgrade to AM2 • MIRES: $16.5M including 30% contingency TMT.INS.PRE.06.034.DRF01

  29. MIRES Review Committee Comments • Overall • “Breakthrough high angular resolution imaging and high spectral resolution science achievable with MIRES on TMT” • “Highly competent team” • Science • Agrees that science identified by team is “Key [MIRES] Science” • star formation, pre-planetary disks, extra-solar planets • Missing important extragalactic science (AGNs, dust, ices) • Low R and imaging science still interesting despite JWST • (and MIRI on JWST might not become a reality) TMT.INS.PRE.06.034.DRF01

  30. MIRES Review Committee Comments • Technical • Proposed MIRES too narrowly conceived - could be more powerful and more attractive to the community • performance could be enhanced relatively easily at modest additional cost • A more versatile MIRES is appropriate for a telescope like TMT • Maximum spectral resolution of 100,000 needs to be better justified • e.g., not adequate for direct detection of planetary light? • SRD should be re-examined • Reduce lowest R to 500 (from 5000)? • MIRAO should include NGS capability, especially at first light • (MIRES team: this might not work because of window transmission) • Status of rNIRES and timing of AM2 is important to requirements • Investigate ways of improving imaging sensitivity given no telescope chopping. • Site should be high (>4000m) and dry(<3mm H2O) TMT.INS.PRE.06.034.DRF01

  31. IRMOS SRDInfrared Multi-Object Spectrograph Deployable IFU spectrometer fed by MOAO • NIR: 0.8-2.5µm • FoV: IFU heads deployable over 5 arcmin field • Image quality: diffraction-limited images, tip-tilt ≤0.015 arcsec rms • Spatial sampling • 0.05x0.05 arcsec pixels, IFU head 2.0 arcsec, ≥ 10 IF units • Spectral resolution • R=2000-10000 over entire J, H, K bands, one band at a time • R=2-50 for imaging mode TMT.INS.PRE.06.034.DRF01

  32. IRMOS Study and Review • Two studies, two very different concepts: • UF, led by S. Eikenberry • Caltech, led by R. Ellis • Review Chair: Sean Adkins, Keck (Instrumentation) • Reviewers • Francois Hammer, Meudon (FLAMES, FALCON(MOAO), Galaxy formation) • Pascal Jagourel, Meudon (FALCON, AO expert) • Miska Lelouarn, ESO (AO modelling) • Mike Bolte, UCSC • Karl Glazebrook, JHU • Francois Wildi, West Switzerland U (AO, MMT adaptive secondary) • Remote reviewers • Colin Cunningham, UKATC (KMOS, ELT Instrumentation) • Markus Kissler-Patig, ESO (IR instrumentation) TMT.INS.PRE.06.034.DRF01

  33. IRMOS/MOAO Review Panel Overall Comments • MOAO • Both conceptual risk (not yet demonstrated, even in lab) and technical risk (e.g., MEMS, open loop control) • MCAO has 3-4yr lead on MOAO • 5arcmin field not adequately justified • (Both teams argued that much science could be done with 2’) • IRMOS • Complex!! • Scaled implementation advisable • Need to consider operations and life-cycle costs SAC: Should the requirement for the IRMOS field of regard remain 5 arcmin? Or would a smaller field instrument that was ready several years in advance be more attractive? TMT.INS.PRE.06.034.DRF01

  34. IRMOS-UF Feasibility Study Results • General • Study scope and depth exceeded typical feasibility study level • Science • Much broader science case than RFP • Technical: Pickoff arm concept • 20 individual pickoffs feeding 20 spectros • Highly modular, scaleable design • Heritage: most components (wfs, pickoff arms, IFU, cryo mechanisms, spectros, etc.) based on previous instruments (Flamingos, Fisica, etc) • except for MOAO aspects (MEMS, open loop, etc) TMT.INS.PRE.06.034.DRF01

  35. IRMOS-UF Feasibility Study Results • Cost • $75M for 20 arms (including 30% contingency) • $55M for 10 arms, $96M for 30 • Opportunity for $10-20M subsidy from Florida? • Schedule • 10 yrs (start 2006Q4, end 2016Q3) TMT.INS.PRE.06.034.DRF01

  36. IRMOS-UF Review Committee Comments • Technical • UF concept is viable: could build one now • But concerned about complexity, reliability, operational overhead, etc. • 20 separate systems (imagine operating and supporting 20 current IR spectros!) TMT.INS.PRE.06.034.DRF01

  37. IRMOS-Caltech Feasibility Study Results • Science • Much broader science case than RFP • Includes extensive simulations, development of programs • Technical: • Very versatile tiled focal plane object selection, fed by large Offner relay (to provide AO woofer) • 16 optical trains feed 4 spectrographs • R = 2000 - 10000 • IFU FOV = 1.5”; 12.5 and 50mas sampling TMT.INS.PRE.06.034.DRF01

  38. IRMOS-Caltech Feasibility Study Results • Costs • $64M (including 30% contingency) for 16 channel 5’ MOAO • $46M (including 30% contingency) for 2’ field version • The above includes the large offner relay for a cost of $1.7M • that seems too low by at least an order of magnitude to me • Schedule • 9 yrs for “first-science” option (July 06 to Oct 2015) • 11 yrs for full version Note that both teams estimate the schedule to be ~10yrs. IRMOS is not a first light instrument. TMT.INS.PRE.06.034.DRF01

  39. IRMOS-Caltech Review Committee Comments • Science • Excellent science case • Technical • Innovative concept, especially versatile pickoff mechanism • More work needed to demonstrate feasibility of tiled focal plane mechanisn • “Spectral dithering” option risky • Offner idea potentially interesting TMT.INS.PRE.06.034.DRF01

  40. WFOS SRD Wide Field Optical Spectrograph • Multi-object spectroscopy over as much of 20’ field as possible • Wavelength range: 0.31-1.1µm (0.31-1.6µm goal). ADC required • Field of view: 75 arcmin2 ; goal: 300 arcmin2 • Total slit length ≥ 500 arcsec • Image quality: ≤ 0.2 arcsec FWHM over any 0.1µm • Spatial sampling: ≤0.15 arcsec per pixel, goal ≤ 0.10 arcsec • Spectral resolution: R=5-5000 for 0.75” slit; goal: 150-6000 • GLAO enhanced image quality a possibility TMT.INS.PRE.06.034.DRF01

  41. WFOS Study and Review • WFOS Study: HIA feasibility study, supported by a “costing study” of MILES by Caltech • ReviewChair: Buell Jannuzi, NOAO (QSO abs lines, NOAO Deep Survey) • Sandro D’Odorico, ESO (Instrumentation) • Sam Barden, AAO (Spectrographs, VPH gratings) • Bernard Delabre, ESO (Optical Design) • Grant Hill, Keck (HIRES support) • Peter Hastings, UKATC (Mechanical design, GMOS) • Gary Schmidt, Steward Obs. (Spectrographs) • Remote reviewers • Andrei Tokovinin, CTIO (GLAO) Caveat: none of the reviewers were major multi-object spectroscopy users; most were single object, higher dispersion spectroscopists TMT.INS.PRE.06.034.DRF01

  42. WFOS Study Results • Science • UV is very important • 340nm is required; strong science to 310nm if telescope coatings allow • R~7500 strongly advocated • Especially for IGM tomography, their top science project • Field is important • although they assumed the SRD field and didn’t defend it • IR extension lower priority • No strong imaging cases emerged TMT.INS.PRE.06.034.DRF01

  43. WFOS Study Results • Technical • WFOS can be designed to meet SRD requirements with reasonable components, but it’s huge. • Can be horizontal or vertical • Horizontal preferred because it eliminates cost and loss of throughput from M4 • Cost • $59M with 30% contingency for “baseline” (4 barrels, 8 cameras, GLAO ready, no IR). Caltech estimate agrees. • Several descopes • One camera per barrel => -24% • Two barrels with 4 cameras => -37% • One barrel with two cameras => -56% • Baseline but not GLAO ready => - 8% • Schedule • Begin conceptual design in Sept 2006, commission in 2014 Q2 TMT.INS.PRE.06.034.DRF01

  44. WFOS Review Committee Comments • HIA study demonstrates that WFOS-SRD is feasible • Panel believes WFOS-SRD is too ambitious for first light • “Unprecedented size” • Considerable cost and schedule risk • Commissioning more difficult than for a simpler instrument • Advocate a simpler MOS for first light if still desired, otherwise consider WFOS-SRD for later • Panel felt that (SRD) field requirement was not well justified TMT.INS.PRE.06.034.DRF01

  45. Size of seeing-limited instruments! • WFOS • 8m diam * 10m high • Size of an 8m telescope! • HROS UCSC • “classic” design • 10m * 11m • 1.6m off-axis parabolic collimators • 1.4m camera lenses • Huge echelle • 3x8 mosaic of gratings • 1m x 3.5m • 8700 pounds => Long lead time for both Deimos TMT.INS.PRE.06.034.DRF01

  46. Is there a “Simple WFOS” • Not that simple for a 30m • For first light must be minimal risk too. • => very restricted performance cf WFOS-SRD • e.g., “ELVIS” (the ultimate refractive design) • Concept originated by Harland Epps for TMT • 8 arcmin diameter field, R = 2500 with 0.75” slit, 0.3” IQ • Still high risk (unless reduce the field): • Required 20” diameter CaF2 (even 14” is challenging and risky) • and had very large articulated cameras (like WFOS-HIA) • A first light WFOS would likely have a maximum resolution of R = 2500 and <~4arcmin(?) diameter field. • The simplest version would still likely cost ~$15M including rotator, wfs, etc. • (cf $8M for LRIS in 1992) TMT.INS.PRE.06.034.DRF01

  47. ELVIS was ambitious too! And still didn’t meet SRD field and resolution requirements! TMT.INS.PRE.06.034.DRF01

  48. HROS SRDHigh Resolution Optical Spectrometer • Seeing limited optical spectrometer • Wavelength range: 0.31-1µm (0.3-1.3µm goal) • Field of view: 10 arcsec • Total slit length 5 arcsec, separation between orders • Spectral resolution: R=50,000 for 1 arcsec slit, R=90,000 with slicer TMT.INS.PRE.06.034.DRF01

  49. HROS Studies and Review • Two studies, very different concepts • UCSC “MTHR” led by Steve Vogt and Connie Rockosi • CASA, Colorado, led by Cynthia Froning • Review chair: Sandro D’Odorico, ESO (Instruments, UVES) • Reviewers • Bernard Delabre, ESO (Optical Design, UVES, ELTs) • Larry Ramsey, Penn State (High resolution spectroscopy) • Peter Hastings, UKATC (mechanical design, GMOS) • Grant Hill, Keck (HIRES support) • Remote reviewers • Sam Barden, AAO (Optical spectrographs) • Andrei Tokovinin, CTIO (AO) TMT.INS.PRE.06.034.DRF01

  50. HROS-UCSC Study results • Science • Well-developed science case for planets • Technical • It is feasible to scale up classical HIRES and UVES to MTHR • R = 50-100,000 (higher with slicers and/or AO) • 300-1100nm; > 450nm per observation • At R=46000 arcsecs with 0.7” seeing, binning detector by 4*4 pixels gives 4 samples per spectral resolution element, 3 in spatial direction => total of 192 pixels (I.e., similar to what is required by CASA image slicer concept) • Still huge: 10m*11m*3m • huge components, e.g., 3*8 mosaic of echelle gratings, 1m*3.5m size • “MODRES”option possible: R=2000-10,0000 option (not cross-dispersed) fed by a few hundred targets with a large fibre positioner • Overlaps or replaces some of WFOS functionality • An optical AO feed could potentially reduce slit size by 3x if willing to live with slit losses in UV-blue and in poor conditions, and then a HIRES or UVES clone would work, at much lower cost. • NB: this option assumes AM2 TMT.INS.PRE.06.034.DRF01

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