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Evidence for a signature of the galactic bar in the solar neighbourhood

D. Raboud·M. Grenon·L. Martinet·R. Fux·S. Udry
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Abstract

Using available kinematical data for a subsample of NLTT stars from the HIPPARCOS mission we confirm the existence of a previously reported local anomaly in the (u,v) plane: the mean motion u for old disc stars, with v < -30 km/s, is largely positive (+19 +/- 9 km/s w.r.t. the Galactic Center). With the use of the newest global self-consistent numerical models of our Galaxy, we show that a bar could be responsible for this observed velocity anomaly. A fraction of our stars have bar perturbed ``hot'' orbits, allowing them to erratically wander from inside the bar to regions outside the corotation, in particular through the solar neighbourhood.

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D. Raboud, M. Grenon, L. Martinet, R. Fux, S. Udry. 1998-05-14. Evidence for a signature of the galactic bar in the solar neighbourhood. https://arxiv.org/abs/astro-ph/9802266

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