English

Building the red sequence through gas-rich major mergers

Cosmology and Nongalactic Astrophysics 2015-05-14 v1

Abstract

Understanding the details of how the red sequence is built is a key question in galaxy evolution. What are the relative roles of gas-rich vs. dry mergers, major vs. minor mergers or galaxy mergers vs. gas accretion? In Wild et al. 2009 we compare hydrodynamic simulations with observations to show how gas-rich major mergers result in galaxies with strong post-starburst spectral features, a population of galaxies easily identified in the real Universe using optical spectra. Using spectra from the VVDS deep survey with z~0.7, and a principal component analysis technique to provide indices with high enough SNR, we find that 40% of the mass flux onto the red-sequence could enter through a strong post-starburst phase, and thus through gas-rich major mergers. The deeper samples provided by next generation galaxy redshift surveys will allow us to observe the primary physical processes responsible for the shut-down in starformation and build-up of the red sequence.

Keywords

Cite

@article{arxiv.0910.1598,
  title  = {Building the red sequence through gas-rich major mergers},
  author = {Vivienne Wild and C. Jakob Walcher and Peter H. Johansson},
  journal= {arXiv preprint arXiv:0910.1598},
  year   = {2015}
}

Comments

4 pages, 7 figures, proceedings of IAU symposium 262 "Stellar populations, planning for the next decade"