Numerical action reconstruction of the dynamical history of dark matter haloes in N-body simulations

Abstract

We test the ability of the numerical action method (NAM) to recover the individual orbit histories of mass tracers in an expanding universe in a region of radius 26Mpc/h, given the masses and redshift-space coordinates at the present epoch. The mass tracers are represented by dark matter haloes identified in a high resolution N-body simulation of the standard LCDM cosmology. Since previous tests of NAM at this scale have traced the underlying distribution of dark matter particles rather than extended haloes, our study offers an assessment of the accuracy of NAM in a scenario which more closely approximates the complex dynamics of actual galaxy haloes. We show that NAM can recover present-day halo distances with typical errors of less than 3 per cent, compared to 5 per cent errors assuming Hubble flow distances. The total halo mass and the linear bias were both found to be constained at the 50 per cent level. The accuracy of individual orbit reconstructions was limited by the inability of NAM, in some instances, to correctly model the positions of haloes at early times solely on the basis of the redshifts, angular positions, and masses of the haloes at the present epoch. Improvements in the quality of NAM reconstructions may be possible using the present-day three-dimensional halo velocities and distances to further constrain the dynamics. This velocity data is expected to become available for nearby galaxies in the coming generations of observations by SIM and GAIA.

12 pages, 9 figures. submitted to MNRAS

References in corpus (17)

• Large scale bias and the peak background split
• GADGET: A code for collisionless and gasdynamical cosmological simulations
• Mass function of dark matter halos
• An analytic model for the spatial clustering of dark matter haloes
• The Milky Way's satellite population in a LambdaCDM universe
• A reconstruction of the initial conditions of the Universe by optimal mass transportation
• Action Principle Solutions For Galaxy Motions Within 3000 Km/s
• On the least action principle in cosmology
• Reconstruction of primordial density fields
• Reconstruction of cosmological initial conditions from galaxy redshift catalogues
• Peculiar Velocity Reconstruction with Fast Action Method: Tests on Mock Redshift Surveys
• The Cosmological Mean Density and its Local Variations Probed by Peculiar Velocities
• Testing the Least Action Principle in an Omega_0=1 Universe
• Reconstruction Analysis of Galaxy Redshift Surveys: A Hybrid Reconstruction Method
• The Least Action Method, CDM and $\Omega$
• The Space Density of Galaxy Peaks and the Linear Matter Power Spectrum
• Predicting the peculiar velocities of nearby PSC-z galaxies using the Least Action Principle

Cited by in corpus (7)

• Action Dynamics of the Local Supercluster
• The Formation of the Local Group Planes of Galaxies
• Observational biases in Lagrangian reconstructions of cosmic velocity fields
• Cosmic velocity--gravity relation in redshift space
• Disc cloaking: Establishing a lower limit to the number density of local compact massive spheroids/bulges and the potential fate of some high-z red nuggets
• Boundary-value problems in cosmological dynamics
• Tracing the environmental history of observed galaxies via extended fast action minimization method