ELUCID - Exploring the Local Universe with reConstructed Initial Density field III: Constrained Simulation in the SDSS Volume

TL;DR

This paper applies a novel reconstruction method to SDSS data, creating a high-resolution constrained simulation that accurately reproduces the cosmic web and galaxy distributions, reducing cosmic variance and improving environmental analysis.

Contribution

It introduces a detailed constrained simulation of the local universe based on SDSS data, enhancing the understanding of galaxy environments and cosmic structures.

Findings

The simulation accurately reproduces the statistical properties of the cosmic web.

Galaxy density correlates strongly with the simulation's density field, with bias depending on luminosity and color.

Cosmic variance is significantly reduced in the constrained simulation.

Abstract

A method we developed recently for the reconstruction of the initial density field in the nearby Universe is applied to the Sloan Digital Sky Survey Data Release 7. A high-resolution N-body constrained simulation (CS) of the reconstructed initial condition, with $3072^3$ particles evolved in a 500 Mpc/h box, is carried out and analyzed in terms of the statistical properties of the final density field and its relation with the distribution of SDSS galaxies. We find that the statistical properties of the cosmic web and the halo populations are accurately reproduced in the CS. The galaxy density field is strongly correlated with the CS density field, with a bias that depend on both galaxy luminosity and color. Our further investigations show that the CS provides robust quantities describing the environments within which the observed galaxies and galaxy systems reside. Cosmic variance is greatly reduced in the CS so that the statistical uncertainties can be controlled effectively even for samples of small volumes.