2003/12/19 by Osamu Nakamura, M. Fukugita, Masataka Fukugita +3 · 3 citations
Environmental Science · Physics and Astronomy · #Galaxies: Formation, Evolution, Phenomena #Remote Sensing in Agriculture #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/386350
Submitted to Astronomical Journal
arxiv created 2003/12/19 · openalex publication_date 2004/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We present a study of the Hα line emission from a sample of 1482 optically selected, morphologically classified bright galaxies (median redshift of 0.05) derived from the Sloan Digital Sky Survey. The luminosity function is calculated for each morphological class and for the total sample. The luminosity function fitted with the Schechter form gives a slope α = -1.43 ± 0.10 for the total sample, and the Hα luminosity density is 10 h ergs s -1 Mpc -3 , where the first error is statistical and the second is systematic. This value is consistent with that derived by Gallego et al. in 1995, but this agreement is caused by a fortuitous cancellation of their neglect of stellar absorption that affects the estimate of extinction corrections and a significant sample incompleteness of emission-line galaxies. The fraction of Hα emitters monotonically increases from early (a few percent for elliptical galaxies) to late types (100% for irregular galaxies), whereas strong emitters exist in all classes of morphological types. We find that 83% of the luminosity density comes from spiral galaxies, 5% from irregular galaxies, and 9% from early-type galaxies; a small number of morphologically disturbed galaxies contribute by 3%.