DEMOGRAPHICS OF SLOAN DIGITAL SKY SURVEY GALAXIES ALONG THE HUBBLE SEQUENCE

  • Moon, Jun-Sung (Department of Astronomy, Yonsei University) ;
  • Kim, Hong-Geun (Department of Astronomy, Yonsei University) ;
  • Choi, Hyunseop (Department of Astronomy, Yonsei University) ;
  • Oh, Kyuseok (Department of Astronomy, Yonsei University) ;
  • Yi, Sukyoung K. (Department of Astronomy, Yonsei University)
  • Published : 2013.04.11

Abstract

We present the statistical properties of a volume-limited sample of 7,429 nearby (z = 0.033-0.044) galaxies from the Sloan Digital Sky Survey Data Release 7. By performing a visual inspection, we classified our sample galaxies according to the Hubble sequence (Hubble 1926, 1936). Then we excluded apparently smaller and flatter galaxies from our database because morphology classification on them turned out to be difficult. Our results cover structural (e.g. concentration index, color, magnitude, stellar mass, etc.), spectroscopic (e.g. velocity dispersion, $H{\beta}$ absorption line, Fe absorption line, Mg absorption line, accretion rate, $H{\alpha}$ emission line, etc.), and environmental (e.g. density, etc.) properties of each morphology type based on morphology distribution. For this analysis, we used the recent re-measurements of spectral line strengths by Oh and collaborators (2011). Our statistics confirm the up-to-date understanding on galaxy populations, e.g., correlations between morphology and line strengths and in turn derived ages and so on.

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