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Proceedings Paper

Final commissioning phase of the AdOpt@TNG module
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Paper Abstract

The AdOptTNG module is an adaptive optics facility permanently mounted at the Nasmyth focus of the 4m-class Telescopio Nazionale Galileo (TNG). Its integration on the telescope started in late November 1998 and first-light of the speckle and tip-tilt modes took place shortly after. Both modes have been offered to the astronomical community and turned out to provide performances close to the expectations. Double stars with separation below 0.1 arcsec have been resolved by the speckle facility. Improvement of the Strehl ratio of a factor two and enhancement in the FWHM from 0.65 arcsec to 0.35 arcsec have been obtained on relatively faint reference stars. The high-speed low noise CCD, namely an 80 X 80 pixel read from the four corners, has been mounted and aligned with the Shack-Hartmann wavefront sensor. A Xinetics mirror with 96 actuators has been calibrated against the wavefront sensor with on-board alignment fibers. This has been done using a modal approach and using Singular Value Decomposition in order to get a reliable interaction matrix. Filtering can be modal too, using a default integrative filter coupled with a limited FIR-fashioned technique. Open loop measurements on the sky provide data to establish open loop transfer functions and realistic estimates of limiting magnitude. High-order wavefront correction loop has been successfully tested on the sky. In this paper we give a description of the overall functionality of the module and of the procedure required to acquire targets to be used as reference in the correction. A brief overview of the very first astronomical results obtained so far on angular size and shape measurements of a few asteroids and sub-arcsec imaging of Planetary Nebulae and Herbig Haro objects is also given.

Paper Details

Date Published: 7 July 2000
PDF: 6 pages
Proc. SPIE 4007, Adaptive Optical Systems Technology, (7 July 2000); doi: 10.1117/12.390303
Show Author Affiliations
Roberto Ragazzoni, Astronomical Observatory of Padova (Italy)
Andrea Baruffolo, Astronomical Observatory of Padova (Italy)
Jacopo Farinato, European Southern Observatory (Italy)
Adriano Ghedina, Ctr. Galileo Galilei (Spain)
Enrico Marchetti, European Southern Observatory (Germany) and Ctr. Galileo Galilei (Germany)
Simone Esposito, Astrophysical Observatory of Arcetri (Italy)
Luca Fini, Astrophysical Observatory of Arcetri (Italy)
Piero Ranfagni, Astrophysical Observatory of Arcetri (Italy)
Fabio Bortoletto, Astronomical Observatory of Padova (Italy) and Ctr. Galileo Galilei (Italy)
Maurizio D'Alessandro, Astronomical Observatory of Padova (Italy)
Mauro Ghigo, Astronomical Observatory of Merate (Italy)
Giuseppe Crimi, Astronomical Observatory of Merate (Italy)

Published in SPIE Proceedings Vol. 4007:
Adaptive Optical Systems Technology
Peter L. Wizinowich, Editor(s)

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