The flux calibration of Gaia

Abstract

The Gaia mission is described, along with its scientific potential and its updated science perfomances. Although it is often described as a self-calibrated mission, Gaia still needs to tie part of its measurements to external scales (or to convert them in physical units). A detailed decription of the Gaia spectrophotometric standard stars survey is provided, along with a short description of the Gaia calibration model. The model requires a grid of approximately 200 stars, calibrated to a few percent with respect to Vega, and covering different spectral types.

17 pages, 9 figures, to appear in "Calibration and standardization of large surveys and missions", held at Fermilab in April 2012. arXiv admin note: substantial text overlap with arXiv:1009.1748, arXiv:1009.4583