DETERMINATION OF STELLAR ROTATION WITH GAIA AND EFFECTS OF SPECTRAL MISMATCH

摘要

Stellar spectra obtained with the Radial Velocity Spectrometer on-board Gaia will enable determination of projected rotational velocities (υ sin i) from rotational broadening of spectral lines. To estimate the accuracy with which υ sin i can be determined for different stellar types and as a function of magnitude, we perform simulations in which 'observed' spectra (as obtained from the Gaia RVS simulator) are fitted with Kurucz spectra from a template library using the least squares method. We compare results on the υ sin i accuracy as obtained in the case of spectra differing only in υ sin i and in the case of a more general spectral mismatch (in T_(off), log g, [Fe/H]).