NGAO Science Instruments Build to Cost Status February 5, 2009 Sean Adkins

2 Introduction Approach to design/build to cost 1.Be sure instrument capabilities are well matched to key science requirements Galaxy assembly & star formation history Nearby Active Galactic Nuclei Measurements of GR effects in the Galactic Center Imaging & characterization of extrasolar planets around nearby stars Multiplicity of minor planets 2.Understand which requirements drive cost 3.Resist the temptation to add features 4.Seek novel ways to save cost a.Exploit redundancies in compatible platforms – e.g. Near-IR imager and Near-IR IFS b.Evaluate ways to break the normal visible/near-IR paradigm of using different detectors c.Work on the problem hard enough to allow creativity to offer more options

3 Overall Performance Requirements High Strehl –Spatial resolution –Sensitivity –Contrast –Wavelength coverage –Required for AGN, GC, exoplanet & minor planet key science cases Imaging –Diffraction limited, 2 to 3 pixel sampling –Available over full AO system wavelength range 0.97 to 2.4 µm required for all key science cases To ~820 nm required for AGN, highest spatial resolution –Background limited performance –Simple occulting spot coronagraph for 0.97 to 2.4 µm High sky coverage –Priority for all key science cases Integral Field Spectroscopy –Diffraction limited sampling (~20 mas) AGN, GC –Larger sampling scales for galaxy assembly and star formation history (50 to 100 mas) –To ~820 nm Required for AGN, highest spatial resolution Desired at ~50 mas for gravitational lensing –FOV ≥ 4“ dia. (all except galaxy assembly) –Spectral resolution ~4000 (for line discrimination, OH removal) –Background limited performance

4 IFS/Imager Structures Some clear commonalities It remains clear that for >$9M we have a challenge if we need to deliver more than one instrument

5 IFS Parameter Flow down

6 Wavelength Coverage

7 Visible and Near-IR Detector QE

8 Detector Performance Visible CCD, read noise 4 e-, ~20% higher than H2RG H2RG single CDS read noise 15 e-