Jean-Marie Mariotti Center

Joint Research Activity 4 ``Integrating Interferometry into Mainstream Astronomy''

VLTI at Paranal

The JMMC plays a leading role in the Joint Research Activity 4 of the European Interferometry Initiative (EII). This project, centered on the VLTI, is one of the 6 JRAs of the european programme OPTICON. Twelve countries participate in this programme (Austria, Belgium, Czech Republic, France, Germany, Hungary, Israel, Italy, Nederlands, Poland, Portugal, United Kingdom), as well as ESA and ESO, for a total of more than twenty laboratories. The resources of the JRA4 are distributed evenly on two work packages.

Work Package 1: Advanced Instruments

WP1.1 Concept to feasibility studies: This work package is managed by Uwe Graser (MPIA) and Denis Mourard (OCA). Its goal is to prepare the second generation of VLTI instrumentation, and is divided in two phases: a conceptual study, and then a feasibility study. The conceptual studies have ended in April 2005, and the results have been presented at the ESO/EII workshop The Power of Optical/IR Interferometry: Recent Scientific Results and Second Generation VLTI Instrumentation that was held in Garching, Germany on April 4-8, 2005. They cover six instruments: two visible light beam combiners, and four infrared beam combiners. In April 2005, the Scientific Council of the EII has recommended that ESO should start two phase A studies for a 4-6 telescopes imaging combiner. The APRES-MIDI (mid-IR 4 beams combiner, PI: Bruno Lopez, OCA) and VITRUV (4-8 beams near-IR imager, PI: Fabien Malbet, LAOG) concepts were ranked as having priority. The feasibility studies of these two instrument concepts has already begun. The final selection by ESO of the second generation VLTI instruments is not announced yet.

WP1.2 Co-phasing and Fringe Tracking: This work package is managed by Mario Gai (Torino Observatory). Its goal is to optimize the performances of the cophasing instruments. For this purpose, a European Working Group has been created, and the tasks have been distributed. The work is in progress.

Work Package 2: Off-line data reduction software

The JMMC is the leader of this work package (PI: Gilles Duvert, LAOG; Project Manager: Gérard Zins, LAOG) that constitutes the software part of the JRA4. This project will provide the european users of the VLTI and the Large Binocular Telescope (LBT) with a set of software tools to analyze interferometric observations. It is divided in 5 parts:

WP2.1 Management and user support: (PI: Gilles Duvert, Project Manager: Gerard Zins) Creation of the web site of the JRA4 with its associated services. A User Support Group (Gaspard Duchêne, LAOG; Pierre Kervella, LESIA) has also been created.

WP2.2 Common software: (PI: Gilles Duvert, Project Manager: Gerard Zins) Developement of a common library of software tools and programming rules. This task is almost completed.

WP2.3 Model Fitting: (PI: Isabelle Tallon-Bosc, CRAL; collaborations: LAOG, LESIA, LUAN, OCA) Creation of a software to model the interferometric observables. A first version of this software will be delivered in 2006.

WP2.4 Astrometry: (PI: Damien Ségransan, Genève; Andreas Quirrenbach, Leiden). Software tools to compute the proper motions and orbital parameters of multiple systems, developement of an interactive data processing system for the PRIMA instrument of the VLTI. The first version of this software will be delivered in 2007.

WP2.5 Image Reconstruction: The goal of this work package is to provide two image reconstruction software systems: one developed from scratch by CRAL and ONERA, and the other extrapolated from the algorithms routinely used for radio interferometer image reconstruction (Granada University). A third software will be dedicated to the analysis of the LBT data (MPIA and MPIfR). A first version of the software will be delivered in 2007-2008.