Stellar population properties for 2 million galaxies from SDSS DR14 and DEEP2 DR4 from full spectral fitting

TL;DR

This study performs full spectral fitting to determine stellar population properties for 2 million galaxies from SDSS DR14 and DEEP2 DR4, providing a comprehensive catalog to support galaxy evolution research.

Contribution

It introduces a large, detailed catalog of stellar population parameters derived from high-resolution spectral fitting, including for DEEP2 galaxies at higher redshift, with assessments of accuracy and consistency.

Findings

Achieved 0.2 dex accuracy in stellar mass at S/N ~20

Found DEEP2 galaxies have a flat stellar mass distribution between 10^9 and 10^11.5 solar masses

Produced a catalog twice as large as previous SDSS data releases

Abstract

We determine the stellar population properties - age, metallicity, dust reddening, stellar mass and the star formation history - for all spectra classified as galaxies that were published by the Sloan Digital Sky Survey (SDSS data release 14) and by the DEEP2 (data release 4) galaxy surveys. We perform full spectral fitting on individual spectra, making use of high spectral resolution stellar population models. Calculations are carried out for several choices of the model input, including three stellar initial mass functions and three input stellar libraries to the models. We study the accuracy of parameter derivation, in particular the stellar mass, as a function of the signal-to-noise of the galaxy spectra. We find that at low redshift, a signal to noise ratio per pixel around 20 (5) allows a statistical accuracy on $\log_{10}(M^{*}/M_{\odot})$ of 0.2 (0.4) dex, for the Chabrier IMF. For the first time, we study DEEP2 galaxies selected by their \OII luminosity in the redshift range $0.83<z<1.03$, finding that they are consistent with a flat number density in stellar mass in the range $10^9<M/M_{\odot}<10^{11.5}$. We find the resulting stellar mass function based on SDSS or eBOSS in agreement with previous studies (Maraston et al. 2013). We publish all catalogs of properties as well as model spectra of the continuum for these galaxies as a value added catalog of the fourteenth data release of the SDSS. This catalog is about twice as large as its predecessors (DR12) and will aid a variety of studies on galaxy evolution and cosmology.