How important is star formation by the spiral density wave in the disk of our galaxy

Journal Article · Sat Sep 15 00:00:00 EDT 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157331· OSTI ID:5730542

Kaufman, M

A method is presented for using the observed distribution of H II regions in a spiral galaxy to calculate the percentage of young stars formed by the spiral density wave. In the disk of our Galaxy, star formation by high-mass stars is responsible for at least 40% of the high-mass stars and is likely to account for 60% of the star births. For the present disk of our Galaxy, the value of the time constant T describing the efficiency of star formation by high-mass stars if (2.4 +- 1.6) x 10/sup 7/ yr, while in normal elliptical galaxies UBV colors imply that the average past value of T is less than or equal to 10/sup 9/ yr. Thus a similar range of values for the efficiency for star formation by high-mass stars may apply both to the present disk of our Galaxy and to the average past evolution of elliptical galaxies. Nevertheless, star formation by high-mass stars is important in the disk of a spiral galaxy: passage of the spiral density wave triggers an episode of star formation which locally increases the number of massive stars and revives star formation by high-mass stars.

• Research Organization: Department of Physics, The Ohio State University
• OSTI ID: 5730542
• Journal Information: Astrophys. J.; (United States), Vol. 232:3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MILKY WAY
STAR EVOLUTION
GALACTIC EVOLUTION
H2 REGIONS
SUPERNOVAE
COSMIC RADIO SOURCES
ERUPTIVE VARIABLE STARS
GALAXIES
STARS
VARIABLE STARS
640105* - Astrophysics & Cosmology- Galaxies
640102 - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources