| Résumé | The NOAO Fundamental Plane Survey (NFPS) is a deep, homogeneous, all‐sky spectroscopic and photometric study of 100 X‐ray selected clusters within 200 h −1 Mpc (z < 0.06) with the principle goal of determining the large‐scale flow of clusters with respect to the CMB. The photometry of tens of thousands of galaxies in two colors (B and R) will yield quantitative morphological information; spectroscopic parameters of early‐type galaxies will include velocity dispersions, line indices, and redshifts. When combined with high‐quality Fundamental Plane parameters, these measurements will shed light on the evolution of galaxies in the cluster and environmental dependences of spectroscopic parameters. Early results include detection of a significant dependence of the Mgb index on cluster‐centric radius for Abell 3558, which can be interpreted as a gradient in metallicity or abundance ratios, but is not compatible with an age gradient. In addition, we have used the photometric catalogues to construct maps of the color‐magnitude scatter as a function of position. Substructures identified in these maps often correspond with known X‐ray/velocity subsystems. |
|---|
