Keck Laser Guide Star Adaptive Optics System: 1 st & 2 nd Milestones AOWG Telecon Oct. 17, 2003 A. Bouchez, J. Chin, A. Contos, S. Hartman, E. Johansson, R. Lafon, D. Le Mignant, P. Stomski, D. Summers, M. van Dam, P. Wizinowich

Topics  Review 1 st light results  Preliminary definition of 2 nd light milestone & progress  Other priorities

LGS AO Top-level Milestones  05Q2 – Operable for science by OA & 1 expert  05Q3 – 1 st queue scheduled science observing  Top-level milestones (as of fall/02): 03Q4 - 1 st corrected images on NIRC2 with laser Achieved Sept. 18 & 19, 2003  04Q1 – LGS AO facility operable by AO experts  04Q2 – 1 st engineering science  04Q3 – 1 st shared risk science

First LGS Milestone Definition  Definition of the first corrected LGS AO images on NIRC2 (KAON 235). Success Criteria: Achieve a Strehl ratio > 0.2 in Kp for the AO corrected image in the following situation: NIRC2 image with an exposure time > 30 sec. Down tip/tilt loop closed on a NGS V > 13 mag. Achieved SR = 0.25 in Kp on a V = 14 NGS. Higher order loop closed on the LGS. Average seeing conditions. Excellent to extraordinary seeing. Telescope elevation > 60  & < 80 . Science object < 5 arcsec from NGS star. NGS < 10 arcsec off the image rotator axis. Both NGS and LGS on-axis for 1 st light. Rotator in vertical angle mode at optimal angle for laser. Also demonstrated in position angle mode.

First LGS Results (UT 9/20) “Audentes Fortuna Juvat” Virgile Extraordinary seeing

HK T Tauri B (UT 9/20) 3 color image: H, K’ & L’ are blue, green & red, respectively. NGS Vmag = 15 Strehl = 4% at H & 12% at K’. FWHM = 0.14, 0.11 & 0.13 mas at H, K’ & L’. Exposure time = 30, 40 & 72 sec at H, K’ & L’. Position angle = counts from LGS on wavefront sensor at 500 Hz The star shown at the bottom right is the 10 6 yr old classical T Tauri star HK Tau A. HK Tau B at top left is believed to lie in the dark lane of a circumstellar disk.

The LGS AO Team in Celebration

Acquisition Camera image of the LGS (UT 9/19 after optimization) LGS Rayleigh scatter LGS FWHM varied from 1.4 to 1.8 arcsec Altitude ~ 88 km

Acquisition Camera image of the LGS with the primary mirror unstacked LGS best segment FWHM from 1.4” when stacked image was 1.7”

Significant Technical Progress (in support of this milestone)  STRAP operational standalone as tip/tilt sensor  LBWFS operating in 1x1 & 2x2 pixel binning  Providing focus to WFS stage & centroids for optimization  Wavefront sensor tracking versus elevation  Image sharpening based on LBWFS centroids successful  Laser image quality & power fairly stable  Laser diagnostics operational  LGS size qualitatively correlated with pointing & PIB images  Laser pointing with M3  Operation scheme & prelim automation successful  Plus:  Laser Traffic Control System operational  EPICS upgrade for WFC command processor operational  K2aoserver operational for idl & Java tools (from HQ)

DM Science Camera STRAP LBWFS TTM WFS NGS Wavefront Controller Focus Centroids Tip/tilt IR transmissive dichroic LGS Sodium transmissive dichroic Lenslets Offload to telescope Offload focus to telescope (Tip/tilt to Laser) Light from Telescope LGS AO Control Pupil Orientation (Subaperture gains) TSS x,y,z stage

Laser Diagnostics

Error Budget

2nd LGS Milestone Definition Proposed Criteria LGS facility operable by AO experts (by end of Dec/03). Performance Success Criteria: 1.Achieve a Strehl > 0.2 in Kp for a V > 15 mag NGS. 2.Achieve a Strehl > 0.1 in Kp for a V > 17 mag NGS. 6.Corrected images on science camera < 5 min after slew. 9.Nod time < 20 sec (including opening & closing loops). Operability Success Criteria: 3.LGS AO operable by 3 AO + 1 laser expert (+ NIRC2 operator). 4.All software tested & released in a controlled version (by Dec. 15) 5.Demonstrate correction over 50° < EL < 85°. 7.Off-axis science demonstrated for a target > 20 arcsec from NGS. 8.Nodding demonstrated over a 5x5” field. Numbers indicate relative priorities. Faint performance higher priority than off-axis operation

2nd LGS Milestone Tasks

2 nd Light Run Summary (Oct. 10&11)  Cirrus/clouds for entire run. Managed to project laser through holes for short periods  Inadequate time to demo good LGS AO correction  Laser progress  Ran from summit control room (no laser access reqd)  Start of night alignment adequate for night  Much progress on understanding laser pointing  LGS AO progress  Progress on punchlist items, especially focus correction  Some training with tools  No progress on STRAP limiting mag since background high again (had been reduced prior to run)  Good NGS science performed through cirrus

Other AO FY04 Milestones

NGS AO Tasks

K2 AO Observing Calendar Sept. None after 9/18. Oct. 2-5 NIRC2; LGS; IF  Nov NIRC2; IF; 17 LGS; NIRC2  Dec. 5-8 NIRC2; 10 LGS; NIRSPAO; LGS; 16-18, 23-26, NIRC2  Jan. 5-8 IF; 5, 9-12, 27 NIRC2  Only ½ night on 1/27  Appropriate gaps for significant AO changes:  15 wk days from Fri. 10/17 to Th. 11/6.  6 wk days from Tue. 11/18 to Tues. 11/25.  9 wk days from Tue. 1/13 to Fri. 1/23.  Larger gaps available for laser changes.

AO 03B Calendar