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arXiv · 0910.1598

Building the red sequence through gas-rich major mergers

Vivienne Wild·C. Jakob Walcher·Peter H. Johansson
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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.

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Vivienne Wild, C. Jakob Walcher, Peter H. Johansson. 2009-10-08. Building the red sequence through gas-rich major mergers. https://doi.org/10.1017/s1743921310002826

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