Three-point correlation functions of SDSS galaxies: Constraining galaxy-mass bias

Cameron K. McBride, Andrew J. Connolly, Jeffrey P. Gardner, Ryan Scranton, Román Scoccimarro, Andreas A. Berlind, Felipe Marín, Donald P. Schneider

Research output: Contribution to journalReview article

35 Scopus citations

Abstract

We constrain the linear and quadratic bias parameters from the configuration dependence of the three-point correlation function (3PCF) in both redshift and projected space, utilizing measurements of spectroscopic galaxies in the Sloan Digital Sky Survey Main Galaxy Sample. We show that bright galaxies (Mr < -21.5) are biased tracers of mass, measured at a significance of 4.5σ in redshift space and 2.5σ in projected space by using a thorough error analysis in the quasi-linear regime (9-27 h -1 Mpc). Measurements on a fainter galaxy sample are consistent with an unbiased model. We demonstrate that a linear bias model appears sufficient to explain the galaxy-mass bias of our samples, although a model using both linear and quadratic terms results in a better fit. In contrast, the bias values obtained from the linear model appear in better agreement with the data by inspection of the relative bias and yield implied values of σ8 that are more consistent with current constraints. We investigate the covariance of the 3PCF, which itself is a measurement of galaxy clustering. We assess the accuracy of our error estimates by comparing results from mock galaxy catalogs to jackknife re-sampling methods. We identify significant differences in the structure of the covariance. However, the impact of these discrepancies appears to be mitigated by an eigenmode analysis that can account for the noisy, unresolved modes. Our joint analysis of both redshift space and projected measurements allows us to identify systematic effects affecting constraints from the 3PCF.

Original languageEnglish (US)
Article number85
JournalAstrophysical Journal
Volume739
Issue number2
DOIs
StatePublished - Oct 1 2011

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Three-point correlation functions of SDSS galaxies: Constraining galaxy-mass bias'. Together they form a unique fingerprint.

Cite this