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gaia early data release 3 documentation

8.3 Comparison to models

8.3.4 Radial velocity distributions

The median of the radial velocity is computed in each healpix bin and shown shown in Figure 8.16 for two magnitude ranges. We see that there is no systematic significant difference between model and data, at least not that can be attributed to the data themselves.

Figure 8.16: Median of radial velocities computed in healpix bins, in km/s, in Gaia EDR3 (left), in GOG20 (middle) and their absolute differences (right), in 2 magnitude ranges 8<G<9 (top), 12<G<13 (bottom).

Figure 8.17 shows the radial velocity averaged over the whole sky per magnitude bin, for Gaia EDR3, Gaia DR2, and GOG20. The Gaia EDR3 values are in agreement with GOG20 at the level of 1 km/s or less for G<14.

Figure 8.17: Radial velocities averaged over the whole sky as a function of magnitude for Gaia EDR3, GOG20, and Gaia DR2.

Summary of the results:

  • •

    Data and model distributions are in overall agreement to G=14, at the level of 1 km/s.

  • •

    At bright magnitudes, the difference is highly reduced compared to Gaia DR2.