Bias and Conditional Mass Function of Dark Halos Based on the Nonspherical Collapse Model

Abstract

Nonspherical collapse is modelled, under the Zeldovich approximation, by six-dimensional random walks of the initial deformation tensor field. The collapse boundary adopted here is a slightly-modified version of that proposed by Chiueh and Lee (2001). Not only the mass function agrees with the fitting formula of Sheth and Tormen (1999), but the bias function and conditional mass function constructed by this model are also found to agree reasonably well with the simulation results of Jing (1998) and Somerville et al. (2000), respectively. In particular, by introducing a small mass gap, we find a fitting formula for the conditional mass function, which works well even at small time intervals between parent and progenitor halos during the merging history.

28 pages, 11 figures, section 3.2 complemented, Fig.1 and Fig. 4 modified, version accepted for publication in ApJ

References in corpus (2)

• An excursion set model of hierarchical clustering: Ellipsoidal collapse and the moving barrier
• An Analytical Approach to the Spin-Distribution of Dark Halos

Cited by in corpus (6)

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• Why does the clustering of haloes depend on their formation history
• Some improvements to the spherical collapse model
• The Annulus-Filtered E and B Modes in CMBR Polarization
• An Analytical Approach to the Spin-Distribution of Dark Halos