Measuring the Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects

Details Measuring the Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects Measuring the Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects

2003-08-19

arxiv.org/abs/astro-ph/0308316v1

Astrophys.J.594:33-41,2003

Astronomy and Astrophysics

Astrophysics

ApJ in press

Scientific paper

10.1086/376830

Since gravitational lensing effects directly probe inhomogeneities of dark matter, lensing-galaxy cross-correlations can provide us important information on the relation between dark matter and galaxy distributions, i.e., the bias. In this paper, we propose a method to measure the stochasticity/nonlinearity of the galaxy bias through correlation studies of the cosmic shear and galaxy number fluctuations. Specifically, we employ the aperture mass statistics $M_{ap}$ to describe the cosmic shear. We divide the foreground galaxy redshift $z_f^2/< N_g^2(z_f)>$ for each redshift bin. Then the ratio of the summation of $^2/< N_g^2(z_f)>$ over the bins to $$ gives a measure of the nonlinear/stochastic bias. Here $N_g(z_f)$ is the projected surface number density fluctuation of foreground galaxies at redshift $z_f$, and $M_{ap}$ is the aperture mass from the cosmic-shear analysis. We estimate that for a moderately deep weak-lensing survey with $z_s=1$, source galaxy surface number density $n_b=30 \hbox {gal}/\hbox {arcmin}^2$ and a survey area of $25 \hbox {deg}^2$, the effective $r$-parameter that represents the deviation from the linear and deterministic bias is detectable in the angular range of 1'-10' if $|r-1|\gsim 10%$. For shallow, wide surveys such as the Sloan Digital Sky Survey with $z_s=0.5$, $n_b=5 \hbox {gal}/\hbox {arcmin}^2$, and a survey area of $10^4 \hbox {deg}^2$, a 10% detection of $r$ is possible over the angular range $1'-100'$.

Affiliated with

Also associated with

No associations

Rating

Measuring the Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects 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 Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measuring the Deviation from the Linear and Deterministic Bias through Cosmic Gravitational Lensing Effects will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-384723