Getting Lucky with Adaptive Optics: Fast Adaptive Optics Image Selection in the Visible with a Large Telescope
Abstract
We describe the results from a new instrument which combines Lucky Imaging and adaptive optics (AO) to give the first routine direct diffraction-limited imaging in the visible on a 5 m telescope. With fast image selection and alignment behind the Palomar AO system we obtained Strehl ratios of 5%-20% at 700 nm in a typical range of seeing conditions, with a median Strehl of approximately 12% when 10% of the input frames are selected. At wavelengths around 700 nm the system gave diffraction-limited 35 mas full width at half-maxima (FWHMs). At 950 nm the output Strehl ratio was as high as 36% and at 500 nm the FWHM resolution was as small as 42 mas, with a low Strehl ratio but with resolution improved by a factor of ~20 compared to the prevailing seeing. To obtain wider fields we also used multiple Lucky Imaging guide stars in a configuration similar to a ground layer AO system. With eight guide stars but very undersampled data we obtained 300 mas resolution across a 30'' × 30'' field of view in the i' band.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2009
- DOI:
- 10.1088/0004-637X/692/1/924
- arXiv:
- arXiv:0805.1921
- Bibcode:
- 2009ApJ...692..924L
- Keywords:
-
- instrumentation: adaptive optics;
- instrumentation: high angular resolution;
- methods: data analysis;
- techniques: high angular resolution;
- techniques: image processing;
- Astrophysics
- E-Print:
- 6 pages, 11 figures. Submitted to ApJ