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Past and future star formation in disk galaxies

1994; IOP Publishing; Volume: 435; Linguagem: Inglês

10.1086/174790

1538-4357

Jr. Kennicutt Robert C., Peter Tamblyn, Charles E. Congdon,

Galaxies: Formation, Evolution, Phenomena

view Abstract Citations (653) References (66) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Past and Future Star Formation in Disk Galaxies Kennicutt, Robert C., Jr. ; Tamblyn, Peter ; Congdon, Charles E. Abstract We have combined Hα 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 ~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. Publication: The Astrophysical Journal Pub Date: November 1994 DOI: 10.1086/174790 Bibcode: 1994ApJ...435...22K Keywords: Astronomical Models; Galactic Evolution; Spiral Galaxies; Star Formation; Stellar Luminosity; Time Measurement; Ultraviolet Spectra; Astronomical Photometry; H Alpha Line; Stellar Mass; Ultraviolet Astronomy; Astrophysics; GALAXIES: EVOLUTION; GALAXIES: LUMINOSITY FUNCTION; MASS FUNCTION; GALAXIES: SPIRAL; GALAXIES: STELLAR CONTENT; STARS: FORMATION full text sources ADS | data products NED (63) SIMBAD (61)