W. M. Keck Observatory’s Next Generation Adaptive Optics (NGAO) Facility Peter Wizinowich, Sean Adkins, Rich Dekany, Don Gavel, Claire Max for NGAO Team: R. Bartos, J. Chin, A. Conrad, A. Delacroix, R. Kupke, C. Lockwood, J. Lyke, E. McGrath, D. Medeiros, D. Morrison, C. Neyman, S. Panteleev, C. Pollard, M. Reinig, T. Stalcup, S. Thomas, M. Troy, K. Tsubota, V. Velur, K. Wallace, E. Wetherell SPIE, San Diego June 28, 2010

2 Context for NGAO – growing demand for LGS-AO on large telescopes 2 Credit: M. Liu ~270 Keck AO science papers ~50% of Keck II science nights

3 NGAO - Next Generation AO Key New Science Capabilities Near Diffraction-Limited in Near-IR (K-Strehl ~80%) AO correction at Red Wavelengths (  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 since z=3 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

4 Flowed-Down Key Architectural Features

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

66 NGAO: AO Layout

77 NGAO: AO Bench

88 LGS Wavefront Sensor Assembly

9 Low Order Wavefront Sensor Assembly

10 DAVINCI – Imager & IFS Entrance window Coronagrap h mask wheel Imager detector head Imager/IFS selector mirror Pupil imager wheel Filter and pupil mask wheels IFS detector head Grating selector wheel On axis imager 28.7" x 28.7" FOV –7 mas pixel scale On axis selectable IFS –50 mas pixel scale FOV 5.6" x 3" –35 mas, FOV 3.92" x 2.1" –10 mas, FOV 1.12" x 0.6" Adkins et al

11 AO Enclosure DAVINCI Instrument Overhead HEPAs LGSWFS Gowning Room Area AO Bench Secondary Instrument Interferometer DSM Thermal Management DM Electronics

12 LGS Facility TOPTICA/MPBC RC Optical

13 Control Loops – LGS AO Example

14 Control Loops – LGS AO Example

15 Control Loops – LGS AO Example

16 Control Loops – LGS AO Example

17 Control Loops – LGS AO Example

18 Control Loops – LGS AO Example

19 The RTC System Architecture is Mapped to the Critical Signal Paths 19 At the heart of the science wavefront control is the Tomography Engine Tomography Tip/Tilt TT Star Sharpenning Reinig & Gavel

20 Science Case Performance Summary Galaxy assembly: 30º zenith angle, 60º galactic latitude, 30 min integ.

21 NGAO Performance vs. Sky Coverage (Galaxy Assembly Science Case) 21 Strehl EE 35 mas EE 50 mas EE 70 mas Resid. TT error Nominal Ensquared Energy (EE) requirement = 30% sky coverage But very little degradation in EE even for 70% sky coverage Nominal Ensquared Energy (EE) requirement = 30% sky coverage But very little degradation in EE even for 70% sky coverage

22 NGAO is robust against conditions and design assumptions

23 NGAO changes the AO observing experience Monte Carlo performance estimate simulating 44 nights observing (Galaxy Assembly science case), drawing random values for r 0, wind speed, sodium abundance, and zenith angle Includes comparison with M. Liu’s measured K2 LGS data ( = 17%), the model prediction for K2 LGS ( = 20%), and NGAO predict ( = 70%)

24 Early Science Benefits from NGAO - 1 NGAO laser launch telescope –NSF-MRI (Aug/09) funding to procure & implement a K2 center launch telescope NGAO laser –Preliminary designs completed (Dec/09) from 2 vendors. Collaboration with ESO, AURA, GMT & TMT. TOPTICA/MPBC selected to begin final design. –MRI proposal submitted to procure & implement 1 st NGAO laser on K2. Collaboration with TMT & ESO

25 Keck II Center Launch + New Laser 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

26 Early Science Benefits from NGAO - 2 PSF reconstruction –Collaboration with Gemini & U. Groningen to demonstrate on-axis NGS AO PSF reconstruction on Gemini & Keck Jolissaint et al., –Plan to implement off-axis LGS AO PSF reconstruction with Keck –MASS/DIMM implemented (Sept/09) as a Mauna Kea facility Focal anisoplanatism reduction –Risk reduction to demonstrate 20% reduction using Cn2 data Tip-tilt vibration reduction –Risk reduction plan to prototype parametric oscillator on K2 AO NIR tip-tilt sensing (no object selection or AO correction) –ATI (Jun/10) funding to implement a near-IR tip-tilt sensor

27 NIR Tip-Tilt Sensor Predicted Performance for High Redshift Galaxies Case

28 Major Keck AO Science Capability Milestones Future Chin ; LMCT -69

In Closing Keck AO has been delivering great science NGAO will ensure cutting edge high angular resolution science for the US community NGAO PD funding from NSF/AURA TSIP Keck AO NGAO