A Catalog of Bulge, Disk, and Total Stellar Mass Estimates for the Sloan Digital Sky Survey

Abstract

We present a catalog of bulge, disk, and total stellar mass estimates for ∼660,000 galaxies in the Legacy area of the Sloan Digital Sky Survey Data Release 7. These masses are based on a homogeneous catalog of gand r-band photometry described by Simard et al. (2011), which we extend here with bulge+disk and Sérsic profile photometric decompositions in the SDSS u, i, and z bands. We discuss the methodology used to derive stellar masses from these data via fitting to broadband spectral energy distributions (SEDs), and show that the typical statistical uncertainty on total, bulge, and disk stellar mass is ∼0.15 dex. Despite relatively small formal uncertainties, we argue that SED modeling assumptions, including the choice of synthesis model, extinction law, initial mass function, and details of stellar evolution likely contribute an additional 60% systematic uncertainty in any mass estimate based on broadband SED fitting. We discuss several approaches for identifying genuine bulge+disk systems based on both their statistical likelihood and an analysis of their one-dimensional surface-brightness profiles, and include these metrics in the catalogs. Estimates of the total, bulge and disk stellar masses for both normal and dust-free models and their uncertainties are made publicly available here.

On the dependence of galaxy morphologies on galaxy mergers

“…4. These fractions do not depend on the bulge classification, since there are no galaxies hosting pseudo-bulges with B/T > 0.7, and in reasonable agreement with both Wilman & Erwin (2012) and Mendel et al (2014). The hatched histograms in the lower row represents (as in ) the fraction of galaxies with classical B/T < 0.1 in the Fisher & Drory (2011) sample.…”

“…2, we see that the KAN15 run of the MORGANA model and the SC-SAM runs provide the best agreement with the Wilman & Erwin (2012) sample, also when B/T < 0.7 model galaxies are compared with sources with a relevant disc component (either S0s or spiral galaxies). However, none of the models and runs considered in this work is able to reproduce the peculiar trends of the Mendel et al (2014) sample.…”

“…We also consider the catalogue of bulge, disk and total stellar mass estimates for galaxies in the Legacy area of the SDSS presented in Mendel et al (2014). Those mass estimates are based on updated SDSS photometry and bulge+disc decomposition, using dual Sérsic profiles (Simard et al 2011).…”

“…We first consider all galaxies satisfying the first 3 cuts as in Bluck et al (2014). We use this catalogue to define a subsample (A) imposing B/T = 0 to all objects with PpS 0.5, in order to obtain a lower limit on the fraction of bulge-dominated galaxies in the Mendel et al (2014) sample. Analogously, we define a subsample (B) assuming B/T = 1 for sources with PpS 0.5, which maximizes the fraction of bulge-dominated galaxies.…”

“…In c 0000 RAS absence of kinematics, an accurate multi-component decomposition requires well resolved imaging at high signal to noise, for which a 2-component (bulge+disk) model can be fit (see e.g. Simard et al 2011;Mendel et al 2014), providing parameters tied to the morphological information. Visual classifications -confirming the absence of disk light and asymmetric features such as bars and spiral arms -provides an alternative approach to identify ellipticals.…”