1. Science with AO A. Bouchez for the Keck AO team

2. Topics Sample scientific programs. Observing strategies. Technical issues. Keck AO, K'

3. Sample scientific programs RequirementsTechnical issues Planetary imaging/spec. Achieve high Strehl. Pointing requirements for spectroscopy. No differential tracking rates allowed. Direction of NIRC2/WFS sky must be controlled. Dense star fields Achieve high contrast. Good sky subtraction. High-contrast imaging High Strehl stability. Precise placement behind coronographic spot. Observing in vertical angle mode Deep imaging Precise pointing during long exposures. Good sky subtraction. FSM range limited. Off-axis spectroscopy Precise pointing during long exposures. Slit orientation. FSM limits may constrain slit orientation. Surveys High observing efficiency. Avoid using auto-acquisition when possible. M and L band imaging Rapid dithering

4. Program 1: Planetary imaging and spectroscopy Example: 24 December 2003 PI: M. Brown (CIT) Program: "Oceans, Mountains & Rivers on Titan". OA: Steven Magee Observing strategy: Use quick 3-position dither pattern for imaging. Cycle through 5 filters. Repeat ad nauseum for 8 hours. Once per night, take spectra of each location on Titan's disk by scanning the slit across Titan: Image (10s) Image through slit (10s) Spectrum (120s) Dither 5" along slit and 0.04" perpendicular Spectrum (120s) Image through slit (10s) image (10s) Operational issues: Make sure that target list has no differential tracking rates. WFS background should be taken in a direction perpendicular to Titan-Saturn vector (e.g. N or S). Use centroid origin scaling in acquisition widget.

5. M. Brown and A. Bouchez, "Evolution of a storm on Titan", GRL 2004, submitted. 11/11/0311/12/0311/13/0311/14/03 K’ (1.95 – 2.30 μm)H 2 (2.11-2.14 μm) K’ (1.95 – 2.30 μm)

6. Program 2: Crowded star field imaging Example: 6 June 2003 PI: A. Ghez (UCLA) Program: "Imaging and spectroscopy of the Galactic Center's stellar population: Studying the properties and environs of the central supermassive black hole." OA: Joel Aycock Observing strategy: Use R=13.2 guidestar 30" from galactic center (GC). Center target (GC) on NIRC2 narrow field. Image with 5-position dither patter, 1" throw. Operational issues: FSM range should not be exceeded (FSM fault) Beware of source confusion on WFS (binary or multiple guide star, etc.), which could lead to tip-tilt oscillations.

7. A. Ghez et al., "Variable Infrared Emission from the Supermassive Black Hole at the Center of the Milky Way", ApJ 601, 2004.

8. Program 3: High-contrast imaging Example: November 30, 2001 PI: Zuckerman (UCLA) Program: "Measuring the border between brown dwarfs and planets". OA: Chuck Sorenson Observing strategy: Use wide field (0.04"/pix) for highest sensitivity & area. Star positioned off detector to minimize ghosts. 15 x 90s images in 5-position dither pattern, pointed 24" N,S,E,W of ε Eridani. Sky frames taken separately, offset 600" from star. Alternate technique: Use coronographic spot and medium/small lyot stop. AO rotator in vertical angle mode: PSF artifacts will be fixed, while astronomical objects rotate around guide star. DAR would be on. Operational issues: Observer will probably redefine FSM pointing origin if using coronographic spot.

9. B. Macintosh et al., "Deep Keck Adaptive Optics Searches for Extrasolar Planets in the Dust of Eridani and Vega", ApJ 594, 2003.

10. Program 4: Deep imaging Example: October 3, 2003 PI: J. Larkin (UCLA) Programe: "CfAO Treasury Survey: AO imaging in the GOODS field" OA: Terry Stickel Observing strategy: Place bright guide-star near corner of NIRC2 wide field. Take long (300s) integrations in tight 15-position dither pattern. 2 filters (H, K') Use faint stars in field to map out distortion and PSF. Operational issues: none

11. T. Glassman et al., "Morphological Evolution of Distant Galaxies from Adaptive Optics Imaging", ApJ 581, 2002.

12. Program 5: Off-axis spectroscopy Example:08/17/03 August 17, 2003 PI: C. Max (UCSC) Program:"AO observations of nearby active galactic nuclei" AO: Gary Puniwai Observing strategy: Use R=12.5 guide star 35" from target (interacting galaxies with active nucleii). Align slit on both nucleii. DAR must be on. Take long (300s) integrations. Offset to sky for sky spectra. Operational issues: FSM range may constrain slit PA. Cannot change rotator angle while FSMs are off pointing center. 1.6 arc sec 35 arc sec

13. Off-axis spectroscopy Constraints on slit PA due to FSM limits

16. HST: J,H,K composite 1.6 arc sec Bright nucleus Faint nucleus Gas in between x 2.00  m 2.08  m2.17  m H2 emission line from shocked or ionized gas (  v=580 km/s) Keck: K-band NIRSPEC Image & spectra R = 12.5 NGS, 35” separation C. Max et al., "Adaptive optics observations of NGC 6240 at the Keck and Lick Observatories", BAAS 32, 2000.

17. Program 6: Surveys Example: Last night! PI: B. Merline (NASA) Program: "Searching for asteroid satellites using AO." OA: Chuck Sorenson Observing strategy: Group targets by sky position (minimize slew time). Group targets by magnitude (minimize acquisition time). Take 4 x 60s integrations in 4-position dither pattern. Move on… Operational issues: Center target on WFS by ACAM pixel position. Avoid running auto-acquisition script on each target.

18. Kaliope (Margot and Brown, 2001) Pulkova (B. Merline et al., 2000) Binary asteroids discovered with Keck AO Sylvia (Brown and Margot, 2001) Antiope (Merline et al., 2001)