Volume 331 - Frontier Research in Astrophysics – III (FRAPWS2018) - High Energy Astrophsyics
Stellar population properties for 2 million galaxies from SDSS DR14 and DEEP2 DR4 from full spectral fitting
J. Comparat
Full text: pdf
Pre-published on: April 15, 2019
Published on: November 20, 2019
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 pub-
lished by the Sloan Digital Sky Survey (SDSS data release 14) and by the DEEP2 (data
release 4) galaxy surveys [Abolfathi et al.(2017), Newman et al. (2013)]. We perform full
spectral fitting on individual spectra, making use of high spectral resolution stellar popu-
lation models [Maraston & Strömbäck (2011), Wilkinson et al. (2017)]. Calculations are car-
ried out for several choices of the model input, including three stellar initial mass func-
tions and three input stellar libraries to the models. In total we provide up to nine mod-
elling of the continuum for each galaxy. We perform spectral model fitting for each
input M11 model: M11-ELODIE, M11-MILES and M11-STELIB [Le Borgne et al. 2003,
Sánchez-Blázquez, P. et al. 2006., Falcón-Barroso et al. 2011, Prugniel et al. 2007] and for three
choices of the stellar initial mass function (IMF), namely Salpeter, [Salpeter et al. 1955],
Chabrier, [Chabrier 2003] and Kroupa, [Kroupa 2001]. Fig 1 shows an example of the firefly’s
outputs for a low redshift galaxy. 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 signal to noise
ratio per pixel around 20 (5) allow a statistical accuracy on log$_{10} (M^*/M_☉)$ 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 [Comparat et al. 2006]. We find that they have stellar masses
with a flat number density in the range $10^9 < M/M_☉ < 10^{11.5}$. We publish all catalogs of prop-
erties as well as model spectra of the continuum for these galaxies in [Comparat et al. (2017)]
and on the web, here https://firefly.mpe.mpg.de/v1_1_0/. This catalog is about
twice as large as its predecessors (DR12) and will aid a variety of studies on galaxy evolution and
cosmology.
DOI: https://doi.org/10.22323/1.331.0036
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