1. WMKO Next Generation Adaptive Optics Science Advisory Team: Introductions & NSAT Charge Taft Armandroff, Mike Bolte, Shri Kulkarni, Hilton Lewis June 11, 2009

2. 2 Introductions NSAT Members: –Laird Close –George Djorgovski –Richard Ellis –James Graham –Michael Liu –Keith Matthews –Mark Morris (chair) –Tomasso Treu Directors NGAO Team

3. 3 Keck AO Science Product 217 refereed science papers (thru May/09) 29% 52% 19% M. Liu 10% 26% 64%

4. 4 Galactic Center Keck LGS AO Science Methane brown dwarfs Bipolar Jet KBO’s

5. 5 Keck AO Science Capabilities Future

6. 6 NGAO Project Milestones & Funding All of the following successfully completed: –Jun/06. Proposal submitted –Apr/08. System Design Review –Nov/08. TMT AO cost comparison –Mar/09. Build-to-cost concept review Preliminary Design Review planned for Apr/10 TSIP provided $2M for the preliminary design ATI (Nov/08) & MRI (Jan/09) proposals submitted for NGAO related activities Private funding being sought MRI-R 2 & TSIP proposals will be submitted this year

7. 7 NGAO System Design Review (April/08) Very Experienced Review Committee: Brent Ellerbroek & Gary Sanders (TMT) Bob Fugate (NMT) & Norbert Hubin (ESO) Andrea Ghez (UCLA) & Nick Scoville (Caltech) “The review panel believes that Keck Observatory has assembled an NGAO team with the necessary past experience … needed to develop the NGAO facility for Keck. It is a sound, though aggressive, strategy to be among the first observatories to develop and depend on advanced LGS AO systems as a means to maintain Keck’s leadership in ground-based observational astronomy for the immediate future.“ “The panel also believes that NGAO is an important pathfinder for the 2 nd generation of AO based instruments for future ELT’s” “The NGAO Science cases are mature, well developed and provide high confidence that the science … will be unique within the current landscape.”

8. 8 NGAO Build-to-Cost Review (March/09) Very Experienced Review Committee: Brent Ellerbroek (TMT) Michael Liu (U. Hawaii) Jerry Nelson (TMT, UCSC) Cost cap with instruments & contingency: $60M then-year dollars "The Committee strongly congratulates the NGAO team for a concise, convincing presentation which demonstrates that the above criteria for further development of the system have been very effectively met. We recommend that the project is now ready to proceed with the Preliminary Design Phase to continue the development of the updated system concept, with no further changes in overall scope or basic architecture either necessary or desirable."

9. 9 NSAT Charter The purpose of the NSAT is to help ensure that the NGAO facility will provide the maximum possible science return for the investment and that NGAO will meet the scientific needs of the Keck community. To that end the NSAT will provide science advice to the NGAO project with an emphasis on the further development of the science cases and science requirements. The NSAT is also expected to provide science input in such areas as performance requirements, operations design, and design trades. The NSAT will report to the Directors, providing a panel of experts for them to consult, and will work closely with the NGAO Project Scientist providing an expert science team that represents a wide range of AO interests in the Keck community.

10. 10 NSAT Responsibilities for the Preliminary Design Collaborate with the NGAO project scientist and project team to: Further develop the NGAO science cases and science case requirements. Evaluate the scientific performance of the NGAO design on various science cases (for example, PSFs reflecting the modeled NGAO performance may be provided for evaluation). Determine what science cases and requirements should drive a phased implementation of NGAO and the scientific impact of a phase implementation. Support funding efforts by contributing to the science portion of proposals and/or making presentations. Determine optimal observing and operations strategies including further development of science case observing scenarios and providing input to the Operations Concept Document and the design of the observing tools. Ensure that NGAO is scientifically competitive by providing input on NGAO’s science competitiveness and complementarity with respect to other facilities.

11. 11 NSAT Responsibilities for the Preliminary Design Collaborate with the NGAO project scientist and project team to: Ensure that the broader Keck community’s input is taken into account in the development of the NGAO Preliminary Design by liaising with the broader community. Promote NGAO in the Keck, national and international communities. Ensure that technical (e.g., design and performance) trades made by the NGAO project have adequate science input by evaluating the science impact of proposed changes. Prepare and present the NGAO science issues and broader perspective to the Directors and SSC.

12. 12 NSAT Longer Term Role The NSAT role and responsibilities in the remaining phases of the NGAO project will be assessed towards the end of the Preliminary Design phase. The Directors will seek input from the NSAT and NGAO project in defining the NSAT’s longer term role.

13. WMKO Next Generation Adaptive Optics Introduction for the NSAT Peter Wizinowich, Sean Adkins, Rich Dekany, Don Gavel, Claire Max, Elizabeth McGrath & the NGAO Team June 11, 2009

14. 14 Presentation Sequence Brief Overview Science Priorities Design & Performance Science Instruments How can the NSAT help?

15. Overview

16. 16 NGAO - Next Generation AO Key New Science Capabilities Near Diffraction-Limited in Near-IR (K-Strehl ~80%) AO correction at Red Wavelengths (0.65-1.0  m) Increased Sky Coverage Improved Angular Resolution, Sensitivity and Contrast Improved Photometric and Astrometric Accuracy Imaging and Integral Field Spectroscopy Key Science Goals Understanding the Formation and Evolution of Today’s Galaxies Measuring Dark Matter in our Galaxy and Beyond Testing the Theory of General Relativity in the Galactic Center Understanding the Formation of Planetary Systems around Nearby Stars Exploring the Origins of Our Solar System

17. 17 How is NGAO different from Keck’s AO today?

18. 18 NGAO System Architecture Key Features: 1.Fixed narrow field laser tomography 2.AO corrected NIR TT sensors 3.Cooled AO enclosure smaller 4.Cascaded relay 5.Combined imager/IFU instrument

19. 19 Project Milestones

20. 20 Cost Estimate in Then-Year $k In FY09 $: $42M for NGAO, $12M for Instrument(s)  $54M total

21. Science Priorities

22. 22 We categorized science cases into 2 classes 1.Key Science Drivers: –These push the limits of AO system, instrument, and telescope performance. Determine the most difficult performance requirements. 2.Science Drivers: –These are less technically demanding but still place important requirements on available observing modes, instruments, and PSF knowledge.

23. 23 “Key Science Drivers” (in inverse order of distance) 1.High-redshift galaxies 2.Black hole masses in nearby AGNs 3.General Relativity at the Galactic Center 4.Planets around low-mass stars 5.Asteroid companions

24. 24 1.Gravitationally lensed galaxies 2.QSO host galaxies 3.Resolved stellar populations in crowded fields 4.Astrometry science (variety of cases) 5.Debris Disks and Young Stellar Objects 6.Giant Planets and their moons 7.Asteroid size, shape, composition “Science Drivers” (in inverse order of distance)

25. 25 Key Science Requirements: 1. Assembly and star formation history of high z galaxies “High Redshift Galaxies” has very wide scope –z > 6: Finding and characterizing galaxies –3 < z < 6:Morphologies, colors –1 < z < 3: Internal kinematics, structure at time of peak star formation and merging To define “Key Science Driver” we focused on 1 < z < 3 –1 < z < 3 epoch: spatial resolution of 10-m telescope has strong impact Prominent emission lines redshifted to J, H, K bands Sufficient signal-to-noise to spatially resolve internal kinematics, star formation rates, metallicity gradients using spatially resolved spectroscopy

26. 26 Cooled AO system for better performance at K-band Target goal: AO to contribute at most 30% (sky + tel) background This opens “typical” z~2.6 galaxies within reasonable observing times ~ 3 hours We have to assess how much it’s worth investing to cool NGAO at K band, in view of JWST’s great advantage in sensitivity

27. 27 Key Science Requirements: 2. Black hole masses in nearby galaxies M-  relation: black hole mass closely correlated with velocity dispersion of stars Spatial resolution: need to resolve the black hole's dynamical sphere of influence r g = GM BH /  2 If you see the Keplerian rise in the rotation curve, mass determination becomes more accurate Simulation: 10 8 M sun BH at 20 Mpc, inclination 60 deg to line of sight

28. 28 Addition of optical bands: advantage for BH mass determination With NGAO, diffraction-limited PSF core at Ca II triplet is major improvement in spatial resolution –Enables many more low-mass black holes to be detected –Better for resolving r g in nearby galaxies, leading to more accurate measurements –NGAO I-band can study high- mass distant galaxies to pin down extreme end of M-  relation Minimum BH mass detectable vs. distance, assuming local M-  relation and  2 resolution elements across r g

29. 29 Key Science Requirements: 3. General relativistic effects in the Galactic Center Measure General Relativistic prograde precession of stellar orbits in Galactic Center Requires astrometric precision of 100  as (now 170  as) and radial velocity precision to 10 km/sec (now 17 km/sec) Need to evaluate optimal spectral resolution Credit: UCLA Galactic Center Group Imaging field 10 x 10 arc sec Near IR IFU spectra, R ≥ 4000, FOV ≥ 1” x 1”, need IR ADC

30. 30 Galactic Center: possibility of detecting general relativistic effects near black hole Use orbits of star(s) that pass very close to black hole Example: general relativistic precession SNR > 10 requires astrometric precision better than 0.1 mas Current astrometric precision of 170  as is only achieved for bright stars like S0-2. Assumes radial velocity measurement errors of 10 km/s

31. 31 Key Science Requirements: 4. Planetary & brown dwarf companions to low mass stars Faintness of low-mass stars, brown dwarfs, and the youngest stars make them excellent NGAO targets Small imaging field ≤ 5 arc sec Relative photometry to 5%, astrometry to PSF FWHM/10, contrast  H = 13 at 1” Instruments: –Imaging 0.9 - 2.4 microns –Single near IR IFU spectroscopy, still need to specify spectral resolution Observing modes: coronagraph needed

32. 32 Contrast Requirements for Planets Around Low-Mass Stars Need to reach at least  H=10 at 0.2” for our primary target sample (planets around nearby old field brown dwarfs). We plan to simulate achievable contrast ratio using reasonable coronagraph + NGAO PSF models Preliminary simulations from SDR indicate a simple coronagraph with a 6 /D spot size may be sufficient for most science cases. Brown dwarf 1/30 mass of Sun (hidden behind occulting mask) Giant planet (2x mass of Jupiter) Simulations by Bruce Macintosh and Chris Neyman

33. 33 Key science requirements: 5. Multiplicity, size, shape of minor planets Minor planet formation history and interiors by accurate measurements of size, shape, companions Small, on-axis imaging field ( ≤ 3 arc sec) Relative photometry to 5%, astrometry ≤ 5 mas, wavefront error ≤ 170 nm, contrast  H  5.5 at 0.5 arc sec Instruments: –Imaging: visible and near-IR –Near IR IFU spectroscopy: 1.5 arc sec field; still need to specify spectral resolution Observing modes: non-sidereal tracking, <10 minute overhead switching between targets Asteroid Sylvia and moons Nix and Hydra Credit: D. Tholen

34. 34 Science Requirements & Performance Budget Process

35. 35 Science Priority Input: SDR Report “The NGAO Science cases are mature, well developed and provide enough confidence that the science … will be unique within the current landscape.” “The science requirements are comprehensive, and sufficiently analyzed to properly flow-down technical requirements.” “… high Strehl ratio (or high Ensquared Energy), high sky coverage, moderate multiplex gain, PSF stability accuracy and PSF knowledge accuracy … These design drivers are well justified by the key science cases which themselves fit well into the scientific landscape.” The panel was concerned about complexity & especially the deployable IFS –“However, the review panel believes that the actual cost/complexity to science benefits of the required IFS multiplex factor of 6 should be reassessed.” –“… recommends that the NGAO team reassess the concept choices with a goal to reduce the complexity and risk of NGAO while keeping the science objectives.” The panel had input on the priorities –“The predicted Sky Coverage for NGAO is essential and should remain a top requirement.”

36. 36 Science Priority Input: Keck Scientific Strategic Plan “NGAO was the unanimous highest priority of the Planetary, Galactic, & Extragalactic (high angular resolution) science groups. “NGAO will reinvent Keck and place us decisively in the lead in high- resolution astronomy. However, the timely design, fabrication & deployment of NGAO are essential to maximize the scientific opportunity.” “Given the cost and complexity of the multi-object deployable IFU instrument for NGAO, …, the multi-IFU instrument should be the lowest priority part of the NGAO plan.” Planetary recommendations in priority order: higher contrast near-IR imaging, extension to optical, large sky coverage. Galactic recommendations in priority order: higher Strehl, wider field, more uniform Strehl, astrometric capability, wide field IFU, optical AO Extragalactic high angular resolution recommendations: a balance between the highest possible angular resolution (high priority) & high sensitivity

37. 37 Science Implications of no Multiplexed d-IFU As a result of our Build-to-Cost approach, we have eliminated the multiplexed d-IFU. –Reduces complexity and decreases risk of overall NGAO system –Available laser power can be utilized to provide excellent performance for science targets over narrow fields (<40”) Science implications: Galaxy Assembly and Star Formation History –Reduced observing efficiency (from 6x to 1x) –Slightly increased performance for single, on-axis target –Decreased overall statistics for understanding galaxy evolution. We will need to carefully select sub-categories of high-z galaxies to focus on. General Relativity in the Galactic Center –Decreased efficiency in radial velocity measurements (fewer stars observed simultaneously) –Can gain back some of this with a single IFU with a larger FOV.

38. 38 Flowdown of Science Priorities (resultant NGAO Perspective) Based on the SDR science cases, SDR panel report & Keck Strategic Plan: 1.High Strehl Required directly, plus to achieve high contrast NIR imaging, shorter AO, highest possible angular resolution, high throughput NIR IFU & high SNR Required for AGN, GC, exoplanet & minor planet key science cases 2.NIR Imager with low wavefront error, high sensitivity, ≥ 20” FOV & simple coronagraph Required for all key science cases. 3.Large sky coverage Priority for all key science cases. 4.NIR IFU with high angular resolution, high sensitivity & larger format Required for galaxy assembly, AGN, GC & minor planet key science cases 5.Visible imaging capability to ~ 800 nm Required for higher angular resolution science 6.Visible IFU capability to ~ 800 nm 7.Visible imager & IFU to shorter 8.Deployable multi-IFS instrument (removed from plan) –Ranked as low priority by Keck SSP 2008 & represents a significant cost Included Excluded

39. 39 Performance vs Science Requirements Key Science DriverSCRD RequirementPerformance of B2C Galaxy Assembly (JHK bands) EE  50% in 70 mas for sky cov = 30% (JHK) EE > 70% in 70 mas for sky cov  90% (K band) Nearby AGNs (Z band for Ca triplet) EE  50% in 1/2 grav sphere of influence EE  25% in 33 mas  M BH  10 7 M sun @ Virgo cluster (17.6 Mpc ) General Relativity at the Galactic Center (K band) 100  as astrometric accuracy  5” from GC Need to quantify. Already very close to meeting this requirement with KII AO. Extrasolar planets around old field brown dwarfs (H band) Contrast ratio  H > 10 at 0.2” from H=14 star (2 M J at 4 AU, d* = 20 pc) Meets requirements (determined by static errors) Multiplicity of minor planets (Z or J bands) Contrast ratio  J > 5.5 at 0.5” from J < 16 asteroid Meets requirements: WFE = 170 nm is sufficient √ √ √ √ √

40. 40 How does NGAO fit into the competitive landscape Other ground-based observatories JWST & ALMA TMT

41. 41 NGAO in the world of 8-10 m telescopes: Uniqueness is high spatial resolution, shorter ’s, AO-fed NIR IFS Most 8-10 m telescopes plan either high contrast or wide field AO Only VLT has narrow-field mode, but has low sky coverage and needs best seeing

42. 42 Competitive Landscape: ALMA Millimeter and sub-millimeter wavelengths (0.35 - 9 mm) Typical spatial resolutions ~ 0.1” Resolutions for widest arrays as low as 0.004” at the highest frequencies ALMA science: regions colder and more dense than those seen in the visible and near-IR by NGAO Keck NGAO and ALMA observations complementary for: –Spatially resolved galaxy kinematics, z < 3 –Debris disks and young stellar objects

43. 43 NGAO comparison to JWST & TMT

44. 44 NGAO comparison to JWST

45. 45 NGAO comparison to TMT NGAO & NFIRAOS wavefront errors are similar ( 162 vs 174 nm rms ). –Similar Strehls. TMT will have higher spatial resolution and sensitivity. –NGAO advantages: earlier science, accumulate experience that TMT will benefit from. NGAO will screen most important targets for TMT (time scarce), do synoptic obsns.

46. 46 Science Team Tasks During PD Phase Ensure that the NGAO science cases fulfill our goals of keeping Keck uniquely powerful and competitive by producing outstanding science. Expand upon goals of “Science Drivers”, and finish documenting the AO performance requirements necessary to achieve these goals. –Iterative with AO Systems Engineering group Detailed science simulations of “Key Science Drivers” to assess the required level of PSF accuracy, stability, uniformity, and knowledge as a function of position and time. Collaboration with IRIS team. Implications for: –achievable astrometric and photometric accuracy –achievable contrast ratio –morphological and spectroscopic studies Incorporate instrument design characteristics as these develop Develop detailed observing scenarios for each “Key Science Driver” to define pre- and post-observing tools and observing sequences.

47. 47 Community Input to Science Team Efforts Continued discussions with Keck community to ensure that science case requirements remain consistent and up-to-date with advancing discoveries, changing methodology, modifications to the current AO system design, and maturing instrument concepts. Input from observers to improve planning tools, observing practices, support, and efficiency. Feedback regarding NGAO science opportunities that complement other ground-based AO and space-based facilities, and that take advantage of the uniqueness space provided by NGAO at Keck.

48. 48 A Key Issue: What are the requirements for PSF stability and knowledge? In System Design phase, we stated requirements in terms of photometric and astrometric accuracy –Develop error budgets These in turn need to flow down to specific levels of PSF stability, uniformity, and knowledge –“Stability” refers to temporal uniformity –“Uniformity” refers to spatial uniformity (specify over what field) –“Knowledge” -- no matter what the actual stability and uniformity, how well do you know the PSF that pertained during a specific science exposure? Develop a set of quantitative measures of “PSF Knowledge” –Different science cases are sensitive to different aspects of the PSF –Examples: total energy in core, details of halo, FWHM of core, etc

49. 49 Science Operations Design Complexity of NGAO requires that we have a good science operations plan and supporting software. We are developing an Observing Operations Concept Document (OOCD) to detail observing process for each science case Science operations design optimizes observing efficiency: (e.g., >80% open shutter time for high-z galaxies) –Pre-observing tools: selection of guide stars, performance and SNR prediction, planning and saving the observation sequences. –Operations tools integrating NGAO, telescope and instruments, allowing for parallel command and multi-system coordination. –Dithering/offsetting/centering using internal steering optics, that do not require opening/closing AO loops and offsetting the telescope. Quality of the final data product: –Use of WFC and ancillary data for monitoring atmospheric conditions and image quality (SR, EE, photometry, etc). –Data archiving for calibration and science products. –PSF calibration, including PSF reconstruction from telemetry. –Post-processing software for IFU data.

50. 50 Pre-observing tools GUIs and high-level operations tools Multi-system Command Sequencer Subsystem Command Sequencer Science Operations Design

51. NGAO Design and Performance

52. 52 NGAO System Architecture Key Features: 1.Fixed narrow field laser tomography 2.AO corrected NIR TT sensors 3.Cooled AO enclosure smaller 4.Cascaded relay 5.Combined imager/IFU instrument

53. 53 Strehl Ratio versus Laser Power 50W in science asterism Science Strehl vs. Laser Power in Science Asterism for 10” radius 3+1 “Tetrad” Asterism Science band Strehl Ratio Laser Power in the Science Asterism [Watts] at spigot for assumed SOR-like return

54. 54 Galaxy Assembly Performance vs. Sky Coverage 1d Tilt Error (mas) % EE (70 mas) K-band b = 30  % EE (41 mas) Complete sky coverage for IFS galaxy assembly science 1-D Tip-Tilt Error [rms mas] H-band Ensquared Energy EE and Tip-Tilt Error vs. % Sky Coverage for Galaxy Assembly case, median seeing Sky Fraction

55. 55 Minor Planets Performance vs. Sky Coverage z-band b = 30  Strehl z-band Strehl > 20% for 50% sky coverage at b=30  1-D Tip-Tilt Error [rms mas] Z-band Strehl Ratio Strehl Ratio and Tip-Tilt Error vs. % Sky Coverage for Minor Planets case, median seeing Sky Fraction

56. 56 Performance versus Seeing Median 37.5% 87.5% High Strehl for a wide range of seeing Strehl Ratio in the respective Science Band Science Strehl vs. Seeing Parameter for 10” radius 3+1 “Tetrad” Asterism r 0 (meters)

57. 57 Off-axis Performance Median seeing Max. IFU radius Max. imager radius Imaging radius requirement Performance Field Performance for Galactic Center Off-axis Distance [arcsec]

58. 58 K2 Center Launch + New Laser MRI proposals - Predicted Performance for T Dwarf Binary Case Factor of 2x improvement  6x in dynamical mass determination R = 16.2 NGS 31” off-axis 50  zenith angle 1% photometry

59. Science Instruments

60. 60 Background NGAO science requirements established a need for certain capabilities in the SD phase –Imaging ~700 nm to 2.4 µm high contrast coronagraph –Integral field spectroscopy in near-IR and visible spatially resolved spectroscopy for kinematics and radial velocities high sensitivity high angular resolution spatial sampling R ~ 3000 to 5000 (as required for OH suppression and key diagnostic lines) Improved efficiency –larger FOV –multi-object capability

61. 61 Constraints & Opportunities Constraints –Cost Need to provide capability within a limited amount of funding Must understand which requirements drive cost –Complexity Must resist the temptation to add features Maximize heritage from previous instruments Opportunities –NGAO offers extended wavelength coverage Significant performance below 1 µm, Strehl ~20% at 800 nm Substrate removed HgCdTe detectors work well below 1 µm –Exploit redundancies in compatible platforms – e.g. Near-IR imager and Near-IR IFS

62. 62 Wavelength Coverage CCD vs. IR FPA –Substrate removed HgCdTe detectors work well below 1 µm –~20% lower QE than a thick substrate CCD –Non-destructive readout takes care of higher read noise of IR array

63. 63 NGAO Imaging Capability Broadband –z, Y, J, H, K (0.818 to 2.4 µm) –photometric filters for each band plus narrowband filters similar to NIRC2 Plate scale –1 or more plate scales selected to optimally sample the diffraction limit, e.g. ( /2D), 8.4 mas at 0.818 µm –Finer sampling may be important for photometry, astrometry –Science requirement for ≥ 20" diameter FOV –Multiple plate scales increase cost and may limit performance Simple coronagraph Throughput ≥ 60% over full wavelength range Sky background limited performance

64. 64 NGAO IFS Capability Narrowband –z, Y, J, H, K (0.818 to 2.4 µm) –~5% band pass per filter, number as required to cover each wave band Spectroscopy –R ~4,000 –High efficiency e.g. multiple gratings working in a single order Spatial sampling (3 scales maximum) 10 mas e.g. ( /2D) at 1 µm 50 to 75 mas, selected to match 50% ensquared energy of NGAO Intermediate scale (20 or 35 mas) to balance FOV/sensitivity trade off FOV on axis –4" x 4" at 50 mas sampling –possible rectangular FOV (1" x 3") at a smaller spatial sampling Throughput ≥ 40% over full wavelength range Detector limited performance

65. 65 Narrowband Science Extra-galactic –IFS will be used for targets with known redshifts Therefore 5% bandpass sufficient? 5% spans Hα and NII lines for example –4 narrowband (5%) filters will cover the K-band –Excitation temperatures Need at least 4 lines Can expect to get 2 or more in each filter Can optimize center wavelength to maximize this Practical to use 2 or more exposures to get enough lines –Imaging spectrograph allows you to detect, and discount image motion for better photometric matching of spectra –Need to have enough FOV to ensure you cover the whole object in each exposure Exoplanet detection –Broadband filters available with narrow FOV ~1" x 1"

66. 66 Narrowband Science Nearby AGN (Black Holes) –Galaxy kinematics CO bandhead 4 to 5% wide (OSIRIS Kn5 filter) Brackett gamma, H_2 emission lines (OSIRIS Kn3 filter) –Remain in that passband to z = 0.03 Same arguments on practicality of non-simultaneous spectra apply –Central Black Hole Narrowband adequate for measuring black hole mass (only 1 line) ~1“ diameter FOV Galactic Center (e.g. GR effects) –Narrowband acceptable for RV measurements –Being used now –Want better SNR Throughput Higher angular resolution to reduce stellar confusion, but keep present FOVs –Could use more FOV

67. 67 Where can the NSAT best contribute? NGAO Team Suggestions

68. 68 Potential NSAT Contributions: based on the Charter The purpose of the SAT is to help ensure that the NGAO facility will provide the maximum possible science return for the investment, and that NGAO will meet the scientific needs of the Keck community. To that end the SAT will provide science advice to the NGAO project, with an emphasis on the further development of the science cases and science requirements. For example: –Advice on overall science priorities –Ensuring that NGAO will play a long term vital role in the era of TMT, JWST, etc. –Advice when there are design trades to be made (science benefit vs. added cost or complexity; priorities between the various science cases) –Advice on the science instrument concept and requirements Seeking community input & informing the community about NGAO developments

69. 69 Potential NSAT Contributions We seek your help in the following near-term areas: –Strengthening the science cases & the definition of the science requirements for NGAO & the NGAO science instruments  Science Case Requirements Document (KAON 455) Ex., science case for optical wavelengths –Provide guidance on the Observing Operations Concepts to ensure they meet the scientific needs of the users  Observing Operations Concept Document (KAON 636) –Understanding what factors limit science performance (astrometry, photometry, contrast, sensitivity, observing efficiency, PSF knowledge, etc.) –Participating in the development of the science instrument requirements and concept –Science input to proposals (Federal & private; MRI-R2 by Aug. 10)

70. 70 Some areas in which we could use help from students or postdocs In many cases the underlying work could be done by grad students or postdocs (would like your help in engaging students & postdocs): Further develop the science cases for optical wavelengths –Science benefit, if any, of working at shorter  but lower Strehl (e.g. H  ) How stable and well-known does the PSF have to be, for the various science cases –AGNs and quasars, planets around low-mass stars, astrometry applications Science simulations in support of the IFU design –Trades between high spatial resolution and high sensitivity, for specific scenarios Astrometry error budget for the Galactic Center –Which aspects are understood today –Of the ones not yet understood, which are most important to tackle 1st Resolved stellar populations science case needs to be quantified –Start by choosing 1 or 2 specific science scenarios that make sense given NGAO’s high Strehl but small field of view Several specific issues involving strategies for high contrast imaging

71. 71 How would you like to help? Are there areas that you think we missed? What additional information do you need? What can we sign you up for?