科研之友
微信
新浪微博
Facebook
分享链接
摘要
We present a new approach for modelling galaxy/halo bias that utilizes the full non-linear information contained in the moments of the matter density field, which we derive using a set of numerical simulations. Although our method is general, we perform a case study based on the local Eulerian bias scheme truncated to second order. Using 200 N-body simulations covering a total comoving volume of 675 h(-3) Gpc(3), we measure several two- and three-point statistics of the halo distribution to unprecedented accuracy. We use the bias model to fit the halo-halo power spectrum, the halo-matter cross-spectrum and the corresponding three bispectra for wavenumbers in the range 0.04 less than or similar to k less than or similar to 0.12 h Mpc(-1). We find that the constraints on the bias parameters obtained using the full non-linear information differ significantly from those derived using standard perturbation theory at leading order. Hence, neglecting the full non-linear information leads to biased results for this particular scale range. We also test the validity of the second-order Eulerian local biasing scheme by comparing the parameter constraints derived from different statistics. Analysis of the halo-matter cross-correlation coefficients defined for the two- and three-point statistics reveals further inconsistencies contained in the second-order Eulerian bias scheme, suggesting it is too simple a model to describe halo bias with high accuracy.
- 出版日期2014-5
