Correlations between Nebular Emission and the Continuum Spectral Shape in SDSS Galaxies

Abstract

We present a statistical study of the correlations and dimensionality of emission lines carried out on a sample of over 40,000 Sloan Digital Sky Survey (SDSS) galaxies. Using principal component analysis, we found that the equivalent widths of the 11 strongest lines can be well represented using three parameters. We also explore correlations of the emission pattern with the eigenspace representation of the continuum spectrum. The observed relations are used to provide an empirical prescription for expectation values and variances of emission-line strengths as a function of spectral shape. We show that this estimation of emission lines has a sufficient accuracy to make it suitable for photometric applications. The method has already proved useful in SDSS photometric redshift estimation.

38 pages, 20 figures

References in corpus (3)

• EAZY: A Fast, Public Photometric Redshift Code
• Alternative diagnostic diagrams and the "forgotten" population of weak line galaxies in the SDSS
• Extinction in Star-Forming Disk Galaxies from Inclination-Dependent Composite Spectra

Cited by in corpus (7)

• Photometric redshifts for the SDSS Data Release 12
• Observed versus modelled u,g,r,i,z-band photometry of local galaxies - Evaluation of model performance
• Quantifying correlations between galaxy emission lines and stellar continua
• Objective Identification of Informative Wavelength Regions in Galaxy Spectra
• Single parameter galaxy classification: The Principal Curve through the multi-dimensional space of galaxy properties
• Emission Line Predictions for Mock Galaxy Catalogues: a New Differentiable and Empirical Mapping from DESI
• The effect of emission lines on the performance of photometric redshift estimation algorithms