Galaxy Products

There are some special products for galaxies which are computed after the spectroscopic pipeline, applying stellar population models to derive a variety of galaxy parameters including stellar masses, emission-line fluxes and equivalent widths, stellar and gas kinematics and velocity dispersions. Each of the stellar population models is applied to all objects that the spectroscopic pipeline calls a galaxy with a good redshift.

These computations have been provided by:

MPA-JHU

We refer to this set of line measurements as the MPA-JHU measurements, after the Max Planck Institute for Astrophysics and the Johns Hopkins University where the technique was developed. The Galspec product provided by the MPA-JHU group is based on the methods of Brinchmann et al. 2004, Kauffmann et al. 2003 and Tremonti et al. 2004, and has been run on previous SDSS data releases and the catalog has been made publicly available since DR4; and has been included in the SDSS data release since DR8. Further details can be found under the MPA-JHU stellar population model algorithm web page.

Portsmouth

The BOSS redshift pipeline now includes the following Portsmouth stellar population model algorithms:

Portsmouth spectro-photometric stellar masses, ages and stellar formation rates based on the star-forming or passive stellar population models of Maraston et al. (2005), Maraston et al. (2009), computed from the best-fit SED model of Maraston et al. (2006).
Portsmouth Emission-line fluxes and equivalent widths, stellar and gas kinematics, based on the stellar population synthesis models of Maraston & Stromback (2011) and Thomas, Maraston & Johansson (2011) applied to BOSS spectra.

Wisconsin

The BOSS redshift pipeline now includes stellar masses and velocity dispersions based on the Wisconsin stellar population model algorithm:

Wisconsin Stellar masses and velocity dispersions are derived from a BOSS spectrum principal component analysis (PCA) of Chen et al. (2012) using the stellar population models of Bruzual & Charlot (2003).