14.3.5 Radial velocities
The median of the radial velocity is computed in each HEALPix pixel and shown shown in Figure 14.46 for the magnitude range . We see that there is no systematic significant difference between model and data, at least not that can be attributed to the data themselves.
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Figure 14.47 shows the radial velocity averaged over the whole sky per magnitude bin, for Gaia DR3, Gaia DR2, and GOG20. From = 4 to 15, the Gaia DR3 values are in agreement with GOG20 at the level of 1.5 or less. We note that it was at the level of 1 or less with Gaia DR2. The dependency on the magnitude seen in the data is not predicted by the model and could indicate some systematics that are not understood yet.
![](cu9/Figures/WP943/vrad_by_gmag.png)
Summary of the results:
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Data and model distributions are in overall agreement to = 15, one magnitude fainter than in Gaia DR2, at the level of 1.5 .
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The dependency on the median of radial velocities over the whole sky versus magnitude, not predicted by the model, could indicate some systematics that are not understood yet.