Star Formation is Very Rapid in Spiral Galaxies
Abstract
We estimate a characteristic timescale for star formation in the spiral arms of disk galaxies, going from atomic hydrogen (H I) to dust enshrouded young stars. Drawing on high resolution H I data from The H I Nearby Galaxy Survey (THINGS) and 24 μm images from the Spitzer Infrared Nearby Galaxies Survey (SINGS) for a sample of 14 nearby disk galaxies, we measure the angular offset between the H I and 24 μm emissivity peaks as a function of radius. We model these offsets assuming a kinematic pattern speed, Ω_{p}, and a timescale, t_{{HI}mapsto 24 μ{m}}, for the time span between the dense H I phase and the existence of young stars heating the surrounding dust. The resulting values of t_{{HI}mapsto 24 μ{m}} for the sample, within the range 1-5 Myr, imply a rapid timescale for massive star formation in spiral arms.
- Publication:
-
Formation and Evolution of Galaxy Disks
- Pub Date:
- October 2008
- Bibcode:
- 2008ASPC..396..163T