| Type |
Conference Paper |
| Names |
Daniel Thomas, O. Steele, C. Maraston, J. Johansson, A. Beifiori, J. Pforr, G. Stroembaeck, C. Tremonti, D. Wake, R. Yan |
| Proceedings Title |
Bulletin of the American Astronomical Society |
| Conference Name |
American Astronomical Society, AAS Meeting #219, #324.05 |
| Volume |
219 |
| Date |
January 1, 2012 |
| URL |
http://adsabs.harvard.edu/abs/2012AAS...21932405T |
| Library Catalog |
NASA ADS |
| Abstract |
SDSS-III/BOSS will take spectra of about 1.5 million massive galaxies up to redshift 0.7, providing a rich data set for galaxy evolution studies. In this talk I present the results from the spectroscopic analysis of 500, 000 galaxy spectra from the first two years of observations. We show that the typical signal-to-noise ratio of BOSS spectra is sufficient to make measurements of stellar velocity dispersion and emission line fluxes. The typical velocity dispersion of a BOSS galaxy is 250 km/s independent of redshift, which reflects the survey design targeting massive galaxies with a uniform mass distribution at all redshifts. As expected, the majority of BOSS galaxies are emission line free, and the fraction of galaxies with a significant detection of weak emission lines is small (about 5 per cent). We show that galaxies at z > 0.4 whose emission lines are produced by star formation activity have blue observed g-r colours and are well separated in the target selection colour-colour space. From stacked spectra we derive chemical element abundance ratios of BOSS galaxies up to z 0.7 through the comparison of measured absorption line indices with stellar population model predictions, and discuss their evolution with redshift. The Science, Technology and Facilities Council (UK) is acknowledged for support. |