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arXiv · 2106.15761

A low density-wave spiral pattern speed, from the tracer separations (age gradient) across a spiral arm in the Milky Way

Jacques P Vallee
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Abstract

We observe the density wave angular pattern speed OMEGA-p to be near 12 to 17 km / s / kpc, by the separation between a typical optical HII region (from the spiral arm dust lane) and using a HII evolution time model to yield its relative speed, and independently by the separation between a typical radio maser (from the spiral arm dust lane) with a maser model.

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Jacques P Vallee. 2021-06-30. A low density-wave spiral pattern speed, from the tracer separations (age gradient) across a spiral arm in the Milky Way. https://doi.org/10.1093/mnras%2Fstab1679

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