Past and future star formation in disk galaxies

Details Past and future star formation in disk galaxies Past and future star formation in disk galaxies

Nov 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...435...22k&link_type=abstract

Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 435, no. 1, p. 22-36

Astronomy and Astrophysics

Astronomy

473

Astronomical Models, Galactic Evolution, Spiral Galaxies, Star Formation, Stellar Luminosity, Time Measurement, Ultraviolet Spectra, Astronomical Photometry, H Alpha Line, Stellar Mass, Ultraviolet Astronomy

Scientific paper

We have combined H-alpha and UBV measurements of 210 nearby Sa-Irr galaxies with new photometric synthesis models to reanalyze the past and future star formation timescales in disks. The integrated photoionization rates and colors of disks are best fitted by a stellar initial mass function (IMF) which is enriched in massive stars by a factor of 2-3 relative to the Scalo solar neighborhood IMF. We have used published surface photometry of spiral galaxies to analyze the star formation histories of disks independent of their bulge properties. The ratio of the current star formation rate (SFR) to the average past rate increases from of order 0.01 in Sa galaxies to 1 in Sc-Irr disks. This confirms that the pronounced change in the photometric properties of spiral galaxies along the Hubble sequence is predominantly due to changes in the star formation histories of disks, and only secondarily to changes in the bulge/disk ratio. A comparison of current SFRs and gas masses of the sample yields median timescales for gas consumption of approximately 3 Gyr, in the absence of stellar recycling. However, a proper time-dependent treatment of the gas return from stars shows that recycling extends the gas lifetimes of disks by factors of 1.5-4 for typical disk parameters. Consequently the current SFRs in many (but not all) disks can be sustained for periods comparable to the Hubble time.

Affiliated with

Also associated with

No associations

Rating

Past and future star formation in disk galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Past and future star formation in disk galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Past and future star formation in disk galaxies will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1021790