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arXiv · 1707.08733

Secular evolution of Milky Way-type galaxies

F. Combes
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Abstract

The internal evolution of disk galaxies like the Milky Way are driven by non-axisymmetries (bars) and the implied angular momentum transfer of the matter; baryons are essentially driven inwards to build a more concentrated disk. This mass concentration may lead to the decoupling of a secondary bar, since the orbit precessing frequency is then much enhanced. Vertical resonances with the bar will form a box/peanut bulge in a Gyr time-scale. Gas flows due to gravity torques can lead to a young nuclear disk forming stars, revealed by a sigma-drop in velocity dispersion. These gas flows moderated by feedback produce intermittent accretion of the super-massive black hole, and cycles of AGN activity. The fountain effect due to nuclear star formation may lead to inclined, and even polar nuclear disks.

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F. Combes. 2017-07-27. Secular evolution of Milky Way-type galaxies. https://arxiv.org/abs/1707.08733

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