10.2.6 Radial velocities and related data

In this section we look at Vrad related outputs of duplicate sources. There were 100 406 pairs of duplicated sources with Vrad data. The data for these pairs should be consistent given their errors, and thus, this set of sources offers a good opportunity for validation of Vrad data. In the plots where we compare the same quantity for the duplicated pairs, the horizontal axis shows the source that is kept in the catalogue, while the vertical one shows the eliminated source.

Figure 10.15: Left: comparison between the radial velocity for duplicate sources. Right: comparison between the radial velocity uncertainty for duplicate sources.

Figure 10.15 shows the comparison of the radial velocity (top) and its uncertainty (bottom) for the pairs. We see that most of the sources follow the 1 to 1 relation for this quantity, with a larger dispersion for small values of radial velocity. The error in radial velocity for the kept source is smaller than for the removed one for 59% of pairs. This is roughly consistent with the fact that 69% of pairs have more transits for the source that is finally kept in the catalogue.

The comparison between the templates used for each component of the duplicate pair is shown Figure 10.16. As we can see from the density of pairs, it seems that most of the pairs have used the exact or similar template. The fractions of pairs having exactly the same template are: 40% for logg, 86% for [Fe/H], and 41% for Teff.

Figure 10.16: Comparison between the templates used for Vrad for duplicate sources for: Top left: surface gravity template; Top right: metallicity template; Bottom: effective temperature template. In these plots, the position of the points has been slightly smeared in order to show better the density of points.