Slow Star Formation in the Milky Way: Theory Meets Observations
Abstract
The observed star formation rate of the Milky Way can be explained by applying a metallicity-dependent factor to convert CO luminosity to molecular gas mass and a star formation efficiency per freefall time that depends on the virial parameter of a molecular cloud. These procedures also predict the trend of star formation rate surface density with Galactocentric radius. The efficiency per freefall time variation with virial parameter plays a major role in bringing theory into agreement with observations for the total star formation rate, while the metallicity dependence of the CO luminosity-to-mass conversion is most notable in the variation with Galactocentric radius. Application of these changes resolves a factor of over 100 discrepancy between observed and theoretical star formation rates that has been known for nearly 50 yr.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2022
- DOI:
- 10.3847/2041-8213/ac6427
- arXiv:
- arXiv:2204.02314
- Bibcode:
- 2022ApJ...929L..18E
- Keywords:
-
- Molecular clouds;
- Star formation;
- 1072;
- 1569;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- In press, Astrophysical Journal Letters 11 pages, 6 figures