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The VLTi Spectro-Imager Instrument for the ESO Very Large Telescope Interferometer

Researcher in charge at IA
Paulo J. V. Garcia


The Portuguese participation in the consortium that is developing the VLTI Spectro-Imager instrument for ESO is a pioneering effort in the sense that for the first time it involves the top national institutions in astronomy and astronomical instrumentation – CAUP, FCUL and INETI. On one hand this project extends and strengthens the ESO instrument development expertise of the FCUL and INETI group that developed the CAMCAO high resolution near-infrared camera that was recently delivered to ESO. The development manufacturing, integration and testing of the CAMCAO camera, by the Portuguese consortium, resulted in accumulated expertise on optics, mechanics, cryogenics, control and image acquisition, as well as integration and testing of complex instruments for ESO. On the other hand, this project continues the partnership between CAUP and LAOG which already produced a joint PhD thesis in the framework of the AMBER VLTI instrument. CAUP is currently coordinating the science group of the VLTI Spectro-Imager, develops in partnership with INESC-Porto R&D in integrated optics recombiners for interferometry, and participates in FP6 projects in this area. The Portuguese team responsibilities in the development of the VLTI Spectro-Imager that are included in this proposal, namely, the development of the alignment an calibration tools and the Relay Optics subsystems make use of the team’s experience gained in previous projects. With the ESO Extremely Large Telescope instrumentation plans still far in the future, the Portuguese participation in VLTI second generation instrument development provides us with a rare opportunity of instrument development for ESO. The VLTI Spectro-Imager is an instrument being designed by a European consortium for the ESO VLT interferometer to perform image synthesis at the mili-arcsecond angular resolution with a moderate to high spectral resolution in the near-infrared domain. The instrument will exploit the unique ESO VLT interferometer facility with four 8m telescopes and several 2m telescopes. The science objectives of the instrument are focused on the kinematics and morphology of compact astrophysical objects at near-infrared wavelengths like the environment of AGN, star formation regions, stellar surfaces and circumstellar environments.

The responsibilities attributed by the international consortium to the Portuguese team are centered in the VLTI Spectro-Imager calibration and alignment tools that performs not only the internal alignment but also the alignment relative to the VLTI, the fringe tracker alignment, the calibration of the internal interferometer response and the calibration of the spectrometer and detector. The responsibilities that were attributed to us include, besides the science studies by CAUP, the development of the relay optics that adapt the light beam coming from the optics combiners to the spectrometer input and include the spectrograph spectral calibration and the polarization separation. Although a lot of work has already been performed on the VLTI Spectro-Imager concept, the instrument is still in an early phase of development easing the integration of the Portuguese team into the overall structure. The project is on Phase a study and is planned to stat the final design studies by the end of 2007, to stat manufacturing in the beginning of 2009 and to perform the assembly integration and testing in 2010. The instrument should be commissioned in 2011. To match this plan with the Portuguese funding structure, the Portuguese participation was split in two projects, the present two year proposal that will cover all studies, prototyping and developments up to the final instrument design and a second project proposal planed to start in 2009 and covering manufacturing integration testing and commissioning.

27 August 2007
31 January 2010

Funding Institution
Fundação para a Ciência e a Tecnologia

Fundação para a Ciência e Tecnologia

Faculdade de Ciências da Universidade de Lisboa Universidade do Porto Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia