Multiple-streaming and the Probability Distribution of Density in Redshift Space

Details Multiple-streaming and the Probability Distribution of Density in Redshift Space Multiple-streaming and the Probability Distribution of Density in Redshift Space

1999-01-10

arxiv.org/abs/astro-ph/9901104v1

Astrophys.J.537:12-20,2000

Astronomy and Astrophysics

Astrophysics

23 pages, 5 ps figures, submitted to ApJ

Scientific paper

10.1086/308991

We examine several aspects of redshift distortions by expressing the redshift-space density in terms of the eigenvalues and orientation of the local Lagrangian deformation tensor. We explore the importance of multiple-streaming using the Zel'dovich approximation (ZA), and compute the average number of streams in real and redshift-space. It is found that multiple-streaming can be significant in redshift-space but negligible in real-space, even at moderate values of the linear fluctuation amplitude ($\sigma < 1$). Moreover, unlike their real-space counter-parts, redshift-space multiple-streams can flow past each other with minimal interactions. Such nonlinear redshift-space effects, which operate even when the real-space density field is quite linear, could suppress the classic compression of redshift-structures predicted by linear theory (Kaiser 1987). We also compute using the ZA the probability distribution function (PDF) of density, as well as $S_3$, in real and redshift-space, and compare it with the PDF measured from N-body simulations. The role of caustics in defining the character of the high density tail is examined. It is found that (non-Lagrangian) smoothing, due to both finite resolution or discreteness and small-scale velocity dispersions, is very effective in erasing caustic structures, unless the initial power spectrum is sufficiently truncated.

Affiliated with

Also associated with

No associations

Rating

Multiple-streaming and the Probability Distribution of Density in Redshift Space 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 Multiple-streaming and the Probability Distribution of Density in Redshift Space, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiple-streaming and the Probability Distribution of Density in Redshift Space will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-252744