Back to Volume
Paper: Emission Corrections for Hydrogen Features of the Graves et al. 2007 Sloan Digital Sky Survey Averages of Early Type, Non-LINER Galaxies
Volume: 423, Galaxy Wars: Star Formation and Stellar Populations in Interacting Galaxies
Page: 161
Authors: Serven, J.; Worthey, G.
Abstract: For the purposes of stellar population analysis, emission corrections for Balmer series indices on the Lick index system in Sloan Digital Sky Survey (SDSS) stacked quiescent galaxy spectra are derived, along with corrections for continuum shape and gross stellar content, as a function of the Mg B Lick index strength. These corrections are obtained by comparing the observed Lick index measurements of the SDSS with new measurements of 13 Virgo Cluster galaxies, and checked with model grids. From the Hα vs. Mg b diagram a linear correction for the observed measurement is constructed using best fit trend lines. Corrections for Hβ, Hγ and Hδ are constructed using stellar population models to predict continuum shape changes as a function of Mg b and Balmer series emission intensities typical of H I regions. The corrections themselves are fairly secure, but the interpretation for Hγ and Hδ indices is complicated by the fact that the near-nuclear Virgo observations have clearly enhanced CN absorption compared to the SDSS sample.
Back to Volume