Untitled - Laboratoire d'Astrophysique de l'Observatoire de Grenoble

at LAOG (in collaboration with Geneva Obs.). This chapter of our activities is understaffed and there is
a pressing need for manpower to maintain our position in the current consortia.
• Radiative transfer in emission lines, interpretation of spectroscopic data (mid-term: 2008-2009)
To follow-up on broad-band continuum observations of disks, on low-resolution spectral classification spectra
of brown dwarfs, or to estimate the physical conditions in ionised atomic jets and accretion columns,
FOST is becoming more and more involved in low, mid- and high spectral resolution observations. However,
no one currently at LAOG as the expertise to deal with radiative transfer in lines. It is important to
fill that void in FOST if we are to push further our understanding of the mechanisms linking accretion and
ejection, and more specifically to elucidate the links between the inner disk and the mass-loss phenomenon
where data is becoming available rapidly with AMBER.
• Dynamical models of (proto-)planetary disks (mid-term:2008-2009)
Today, LAOG has access to powerful (symplectic) codes able to calculate the dynamics of dust disks, without
gas, or follow the gas disk, but without dust. The advances permitted by such codes are tremendous,
but it is absolutely clear that disks around young stars are made of gas and dust and both are important:
gas controls the dynamics, dust controls the temperature equilibrium, roughly speaking. In order to look
for traces of planets, to understand the dynamics of disks, and ultimately their evolution, FOST needs
to develop new numerical tools able to deal simultaneously with the gas and dust components of disks.
These codes must be fast and stable to follow the evolution over a long time span. Furthermore, these
codes must be coupled to radiative transfer tools in order to compare with the observations. This is an
extremely complex problem but tentative solutions have been imagined and an international collaboration
has been started to develop such new tools. FOST, currently leading the programme, is understaffed
(because of teaching load) to develop these new tools and help is needed.
• Physical characterisation of Exoplanets (long term: 2009-2010)
LAOG is PI in two major projects for future instruments that will allow to study the physics of extrasolar
planets: Planet Finder (a second generation AO system for the VLT telescope), and VITRUV (a
second generation, multi telescope recombiner for VLTI). These instruments are expected to provide direct
images and low-resolution spectroscopy of exoplanets. Today, the expertise to exploit these data sets does
not exist at LAOG. Acquiring this expertise in complex data reduction and in planetary physics is a top
long-term priority for FOST and for LAOG.
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