Interferometric fringes with MACAO-VLTI corrected starlight and VINCI

Robin Arsenault; Pierre Kervella; Rob Donaldson; Markus Erdmann Kasper; Enrico Fedrigo; Anders Wallander; Markus Schoeller; Nico Housen; Francoise Delplancke; Fernando Salgado; Christophe Dupuy; Norbert N. Hubin; Liviu Ivanescu; Sylvain Oberti; Jerome Paufique; Silvio Rossi; Markus Wittkowski

doi:10.1117/12.552574

25 October 2004 Interferometric fringes with MACAO-VLTI corrected starlight and VINCI

Robin Arsenault, Pierre Kervella, Rob Donaldson, Markus Erdmann Kasper, Enrico Fedrigo, Anders Wallander, Markus Schoeller, Nico Housen, Francoise Delplancke, Fernando Salgado, Christophe Dupuy, Norbert N. Hubin, Liviu Ivanescu, Sylvain Oberti, Jerome Paufique, Silvio Rossi, Markus Wittkowski

Author Affiliations +

Proceedings Volume 5490, Advancements in Adaptive Optics; (2004) https://doi.org/10.1117/12.552574
Event: SPIE Astronomical Telescopes + Instrumentation, 2004, Glasgow, United Kingdom

Abstract

We report on observations with MACAO-VLTI to feed the VLT Interferometer in November 2003. The purpose of this observing run was to optimize the feed to the VLTI by varying certain parameters of the curvature AO system and of the interferometer instrument VINCI. All along the main concern about this instrument combination was the differential piston introduced by 2 independent AO systems. A special so-called “piston removal algorithm” has been developed especially for this purpose. Each DM Influence Function is carefully characterized and a pure piston mode is defined to compensate piston over the pupil produced by a given voltage set. Piston is reduced by ~20 using this algorithm. It was found that decreasing the system main gain, while reducing strehl ratio, also reduces high frequency vibrations on the DM and therefore OPD variations. A control frequency of 420 Hz instead of the nominal 350 Hz was found to improve substantially the coupling by reducing the excitation of the DM resonance (~700Hz). On bright stars, an improvement of a factor of 30 in the flux injection into the VINCI fibers was measured. Following these tests a successful observation of the active nucleus of NGC 1068 was performed leading to a visibility of 40.4±5.4% on an average baseline of 45.84 m. The K magnitude in the 60 mas central source is 9.2±0.4. The results already put some interesting constraints on the inner torus and central engine of the nucleus of NGC 1068 but mostly show that the combination MACAO-VLTI and VINCI opens the realm of extragalactic astronomy to interferometry.

Citation Download Citation

Robin Arsenault, Pierre Kervella, Rob Donaldson, Markus Erdmann Kasper, Enrico Fedrigo, Anders Wallander, Markus Schoeller, Nico Housen, Francoise Delplancke, Fernando Salgado, Christophe Dupuy, Norbert N. Hubin, Liviu Ivanescu, Sylvain Oberti, Jerome Paufique, Silvio Rossi, and Markus Wittkowski "Interferometric fringes with MACAO-VLTI corrected starlight and VINCI", Proc. SPIE 5490, Advancements in Adaptive Optics, (25 October 2004); https://doi.org/10.1117/12.552574

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available