2.4 Simulation known issues

We summarize here the main known issues of GUMS/GOG 20 simulations :

• •

  RR Lyrae stars are missing.

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  In GOG, the number of outliers, both in astrometry and photometry, is larger than expected from the simulated errors.

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  Very young stars have wrong circular velocity, see the correction procedure proposed in Section 2.2.2.

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  Stars beyond the Galactic centre have a wrong velocity, see Section 2.2.2.

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  Wrong extrapolation of the asymmetric drift, affecting a few thin disk stars, see Section 2.2.2.