[Previous] | [Session 58] | [Next]

[58.02D] CAIRNS: The Cluster And Infall Region Nearby Survey

K. Rines (CfA), M.J. Geller (SAO)

CAIRNS (the Cluster And Infall Region Nearby Survey) is a large spectroscopic survey of the infall regions surrounding eight nearby, X-ray luminous, rich clusters of galaxies. We collect over 15,000 redshifts (over 5,000 new or remeasured) within 5-10 h^-1Mpc of the centers of the clusters. We determine cluster membership and the mass profiles of the clusters based on the phase space distribution of the galaxies using the caustics method described by Diaferio & Geller (1997) and Diaferio (1999). The mass profiles are fit well by functional forms based on numerical simulations (e.g., the NFW profile) but exclude the singular isothermal sphere. Our survey shows that the predicted infall pattern is ubiquitous in clusters over a large mass range. The mass profiles inferred from the caustics are in excellent agreement with independent X-ray estimates at small radii and virial estimates at intermediate radii. We explore the relation between mass and light in these clusters using infrared photometry from the 2-Micron All-Sky Survey (2MASS). These measurements probe the degree of bias or antibias in clusters as well as constrain the mass density of the universe.

This work was supported by the Smithsonian Institution.

The author(s) of this abstract have provided an email address for comments about the abstract: krines@cfa.harvard.edu

[Previous] | [Session 58] | [Next]

Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.