Uppsala universitet

Andreas J. Korn

Work related to Gaia

Gaia is an astrometric space mission currently in the 'detailed design phase' to be launched in late 2011. Apart from measuring the distances and space motions of one billion stars, it aims at deriving basic stellar parameters for a significant fraction of its targets. This will be achieved on the basis of low-resolution spectra (80 pixels covering the optical and near infrared) and medium-resolution spectroscopy (300 Å around the infrared calcium triplet lines). See the ESA Gaia webpage for more details.

Work package 'Synthetic Stellar Spectra'
In Gaia's Coordination Unit 8 ('Astrophysical Parameters') I coordinate the computation of synthetic stellar spectra (together with Frédéric Thévenin, Nice). These data serve a twofold purpose: they are now used for testing and training the codes. In the end, they will be used to extract all possible information that the observed data contain.
There is a GaiaWiki page (for registered users) giving more details and offering a forum for related discussions. The current version of the work-package work breakdown structure (WBS) can be downloaded from here as well (see below).

Solar-type Stars
In a joint effort with people at Nice and elsewehere, we are improving the level of realism in the modelling of solar-type stars. A long-term goal is the construction of self-consistent hydrodynamic model atmospheres with (full) consideration of departures from LTE. In particular when it comes to comparisons on an absolute scale (e.g. cosmological age determinations at the metal-poor turnoff) considering effects from 3D, non-LTE and diffusion will be crucial to remove systematic biases that plague classical analyses. We will make sure that Gaia profits from this development.
See the SAM4Gaia page for more details.

Related Gaia documents

  • CU8 Input Data Format and Content. A discussion document
    Frémat Y., Bailer-Jones C.A.L., Drimmel R., Janotto A.-M., Thévenin F., Vallenari A., Blomme R., Damerdji Y., Kontizas M., Kochukhov O., Korn A.J., Outeiro M., Recio-Blanco A., Smith K., Torres M. (2009)
  • Calibration of the General Stellar Parametrizer algorithms using ground-based observations
    Heiter U., Soubiran C., Korn A.J. (2008)
  • Interface Control Document for the Gaia spectral libraries
    évenin F., Korn A.J., Soubiran C., Janotto A.-M., Sartoretti P., Sordo R., Tsalmantza P., Vallenari A. (2008)
  • Work Breakdown Structure for GWP-S-811-10000
    Korn A.J. & Th
    évenin F. (2006)
  • Need for atomic/molecular data for Gaia astrophysical parametrization
    Korn A.J., Barklem P., Bigot L., Fremat Y., Lanzafame A., Plez B. (2005)

© 2006 UAO, Box 515, 75120 Uppsala
Responsible for this page: Andreas Korn
Updated: 2009-01-14