ar X iv : a st ro - p h / 95 10 06 1 v 3 1 D ec 1 99 5 The current Star Formation Rate of the Local Universe
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چکیده
The Universidad Complutense de Madrid (UCM) Survey is a long-term project aiming at finding and analysing star-forming galaxies detected by their Hα emission in Schmidt objective-prism plates. The instrumental set-up limits the volume of the Universe surveyed to a redshift z ∼< 0.045. So far we have discovered several hundred emission-line galaxies (ELGs) undergoing star formation at a wide range of levels. Analyzing a complete sample of ELGs from the UCM survey we have computed the Hα luminosity function for the star-forming galaxies in the surveyed volume of the Universe. A Schechter function provides a good fit to the Hα luminosity function with the following parameters: α = −1.3± 0.2; L(Hα) = 10 erg s and φ = 10 Mpc for H0 = 50 km s −1 Mpc. Integrating over the full range of luminosities, we obtain an Hα luminosity density of 10 erg s Mpc. Using the Hα emission as a star formation rate (SFR) estimator, this translates into a SFR density for the Local Universe of 0.013 −0.005 M⊙ yr −1 Mpc in star-forming galaxies with EW (Hα+[NII]) > 10Å and z ∼< 0.045, for a Scalo Initial Mass Function. This is the first observational determination of this quantity, which will provide a direct test of current galaxy formation and evolution models. Subject headings: Galaxies: luminosity function, fundamental parameters
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تاریخ انتشار 1995