Home of MagAO and MagAO-X.
Today we raised our hexapod-mounted adaptive secondary mirror (ASM) into the Arcetri test tower in Florence, Italy. The large tower will allow us to operate the secondary at the same focal length and optical conjugates as the Magellan telescope in Chile. We’ll use this test setup to interferometrically test the performance of our ASM and to close the loop on our full AO system.
The below image is our 92% Strehl Sloan r’ band image with our triplet ADC and dichroic beamsplitter in the beam. The slight elongation of the PSF and the asymetric contrast of the fringes are due to the “zenith spike” effect of the ADC. This effect is predicted by our models and will not manifest itself on-sky when the atmosphere will counteract the residual chromatism of the ADC.
Pictures from the fit check have been posted on flickr by the Magellan Observatory. Here’s a photo of the PI hard at work tweaking the handling cart.
More at their flickr page
On March 10, 2011 the MagAO secondary shell had its frontside successfully aluminized at the University of Arizona, Steward Observatory coating facility in Tucson by Richard Sosa and Gary Rosenbaum. This also took a lot of hard work by Jason Lewis and Victor Gasho.
After completing our work with the laser, we switched to a white light source to test the camera’s performance in broad band filters. This is our PSF in the Sloan Digitial Sky Survey (SDSS) i’ filter (a nice set of filter curves is here), which passes light from roughly 0.684 to 0.840 microns. A theoretical Airy pattern is shown for comparison, and Laird calculates our Strehl ratio as 94% – meaning that our optics are very good.
This image is taken without the ADC in the beam. In the laboratory, without the dispersion of an atmosphere to act against it, the residual chromatism of the ADC would slightly degrade the image quality of a broadband source (see Kopon 2008). This “zenith spike” effect was predicted and does not manifest itself on-sky.
