Measuring the Nonlinear Biasing Function from a Galaxy Redshift Survey

Details Measuring the Nonlinear Biasing Function from a Galaxy Redshift Survey Measuring the Nonlinear Biasing Function from a Galaxy Redshift Survey

2000-02-08

arxiv.org/abs/astro-ph/0002170v2

Astronomy and Astrophysics

Astrophysics

23 pages, 7 figures, revised version, accepted for publication in ApJ

Scientific paper

10.1086/309331

We present a simple method for evaluating the nonlinear biasing function of galaxies from a redshift survey. The nonlinear biasing is characterized by the conditional mean of the galaxy density fluctuation given the underlying mass density fluctuation, or by the associated parameters of mean biasing and nonlinearity (following Dekel & Lahav 1999). Using the distribution of galaxies in cosmological simulations, at smoothing of a few Mpc, we find that the mean biasing can be recovered to a good accuracy from the cumulative distribution functions (CDFs) of galaxies and mass, despite the biasing scatter. Then, using a suite of simulations of different cosmological models, we demonstrate that the matter CDF is robust compared to the difference between it and the galaxy CDF, and can be approximated for our purpose by a cumulative log-normal distribution of 1+\delta with a single parameter \sigma. Finally, we show how the nonlinear biasing function can be obtained with adequate accuracy directly from the observed galaxy CDF in redshift space. Thus, the biasing function can be obtained from counts in cells once the rms mass fluctuation at the appropriate scale is assumed a priori. The relative biasing function between different galaxy types is measurable in a similar way. The main source of error is sparse sampling, which requires that the mean galaxy separation be smaller than the smoothing scale. Once applied to redshift surveys such as PSCz, 2dF, SDSS, or DEEP, the biasing function can provide valuable constraints on galaxy formation and structure evolution.

Affiliated with

Also associated with

No associations

Rating

Measuring the Nonlinear Biasing Function from a Galaxy Redshift Survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Measuring the Nonlinear Biasing Function from a Galaxy Redshift Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measuring the Nonlinear Biasing Function from a Galaxy Redshift Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-558241