The Environmental Dependence of the Evolving S0 Fraction

March 2010 • 2010ApJ...711..192J

Authors • Just, Dennis W. • Zaritsky, Dennis • Sand, David J. • Desai, Vandana • Rudnick, Gregory

Abstract • We re-investigate the dramatic rise in the S0 fraction, f _S0, within clusters since z ~ 0.5. In particular, we focus on the role of the global galaxy environment on f _S0 by compiling, either from our own observations or the literature, robust line-of-sight velocity dispersions, σ's, for a sample of galaxy groups and clusters at 0.1 < z < 0.8 that have uniformly determined, published morphological fractions. We find that the trend of f _S0 with redshift is twice as strong for σ < 750 km s^-1 groups/poor clusters than for higher-σ, rich clusters. From this result, we infer that over this redshift range galaxy-galaxy interactions, which are more effective in lower-σ environments, are more responsible for transforming spiral galaxies into S0's than galaxy-environment processes, which are more effective in higher-σ environments. The rapid, recent growth of the S0 population in groups and poor clusters implies that large numbers of progenitors exist in low-σ systems at modest redshifts (~0.5), where morphologies and internal kinematics are within the measurement range of current technology.

Observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution; and based on data collected at the Magellan Telescope, which is operated by the Carnegie Observatories.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2010ApJ...711..192J
• PDF https://iopscience.iop.org/article/10.1088/0004-637X/711/1/192/pdf
• PDF https://stacks.iop.org/0004-637X/711/192/pdf
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2010ApJ...711..192J
• PREPRINT http://arxiv.org/abs/1001.2008
• ELECTR https://doi.org/10.1088%2F0004-637X%2F711%2F1%2F192