| Issue |
EAS Publications Series
Volume 45, 2010
GAIA: At the Frontiers of Astrometry
|
|
|---|---|---|
| Page(s) | 155 - 160 | |
| DOI | https://doi.org/10.1051/eas/1045027 | |
| Published online | 15 February 2011 | |
C. Turon, F. Meynadier and F. Arenou (eds)
EAS Publications Series, 45 (2010) 155-160
Gaia spectro-photometry absolute calibration and comparison to classical systems
INAF, Osservatorio Astronomico, via Ranzani 1,
40127
Bologna,
Italy
e-mail: carla.cacciari@oabo.inaf.it
The Gaia spectro-photometric data consist of white-light G magnitudes from unfiltered fluxes measured in the astrometric field CCDs, and low resolution prism spectra measured in the blue (BP) and red (RP) CCDs. The integrated flux of these BP and RP spectra will yield GBP and GRP magnitudes as two broad passbands. The internal flux calibration will correct for all possible instrumental effects and produce mean spectral energy distributions in an internally defined flux scale. The purpose of the absolute flux calibration is to tie this flux scale to physical units by means of spectro-photometric standard stars that rely ultimately on Vega’s absolute flux scale. The characteristics of the Gaia spectrophotometric system will be described, and the absolute calibration process will be outlined and compared with examples of classical systems.
© EAS, EDP Sciences 2011