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Pattern speeds in the Milky Way

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 نشر من قبل Ortwin Gerhard
 تاريخ النشر 2010
  مجال البحث فيزياء
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 تأليف Ortwin Gerhard




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A brief review is given of different methods used to determine the pattern speeds of the Galactic bar and spiral arms. The Galactic bar rotates rapidly, with corotation about halfway between the Galactic center and the Sun, and outer Lindblad resonance not far from the solar orbit, R0. The Galactic spiral arms currently rotate with a distinctly slower pattern speed, such that corotation is just outside R0. Both structures therefore seem dynamically decoupled.



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