Demographics of galactic bulges in the local Universe through UV and Optical windows

  • Kim, Keunho (Department of Astronomy, Yonsei University) ;
  • Oh, Seulhee (Department of Astronomy, Yonsei University) ;
  • Jeong, Hyunjin (Korea Astronomy and Space Science Institute) ;
  • Yi, Sukyoung K. (Department of Astronomy, Yonsei University)
  • Published : 2014.10.13

Abstract

Bulges of galaxies are thought to have formed and grown at least in part through galaxy mergers, and thus an accurate derivation of their properties can be an effective course to test/confirm our understanding on their formation and evolution in the standard hierarchical merger paradigm. We have generated a sample of galaxy bulges (n = 15,423) in the nearby (0.005 < z < 0.05) universe from the SDSS DR7 and GALEX GR6plus7 databases and derived their structural and photometric properties by means of SExtractor and GALFIT application. Most notable properties include bulge-to-total luminosity ratio, effective radius, disk scale length, ellipticity, and position angle. The UV properties of the bulges have also been analyzed to infer their recent star formation history. A spectroscopic analysis has been performed using their absorption and emission line strengths measured and released by the OSSY team. We present our preliminary results from our investigation mainly focused on stellar population properties and discuss their implications on the formation of bulges.

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