Related papers: A random-walk model for dark matter halo spins
We describe a semi-analytic model to predict the triaxial shapes of dark matter halos utilizing the sequences of random merging events captured in merger trees to follow the evolution of each halo's energy tensor. When coupled with a simple…
We model the acquisition of spin by dark-matter halos in semi-analytic merger trees. We explore two different algorithms; one in which halo spin is acquired from the orbital angular momentum of merging satellites, and another in which halo…
For idealized (spherical, smooth) dark matter halos described by single-parameter density profiles (such as the NFW profile) there exists a one-to-one mapping between the energy of the halo and the scale radius of its density profile. The…
We employ a stochastic approach to probing the origin of the log-normal distributions of halo spin in N-body simulations. After analyzing spin evolution in halo merging trees, it was found that a spin change can be characterized by a…
Various laboratory-based experiments are underway attempting to detect dark matter directly. The event rates and detailed signals expected in these experiments depend on the dark matter phase space distribution on sub-milliparsec scales.…
We propose a new explanation for the origin of angular momentum in galaxies and their dark halos, in which the halos obtain their spin through the cumulative acquisition of angular momentum from satellite accretion. In our model, the…
I present results from numerical N-body simulations regarding the effect of merging events on the angular momentum distribution of galactic halos as well as a comparison of halo growth in Press-Schechter vs. N-body methods. A total of six…
We use a large cosmological N-body simulation to study the origin of possible correlations between the merging history and spin of cold dark matter halos. In particular, we examine claims that remnants of major mergers tend to have…
A common approach in semi-analytic modeling of galaxy formation is to construct Monte Carlo realizations of merger histories of dark matter halos whose masses are sampled from a halo mass function. Both the mass function itself, and the…
We perform a set of non-radiative hydrodynamical simulations of merging spherical halos in order to understand the angular momentum (AM) properties of the galactic halos seen in cosmological simulations. The universal shape of AM…
The merger and accretion probabilities of dark matter halos have so far only been calculated for an infinitesimal time interval. This means that a Monte-Carlo simulation with very small time steps is necessary to find the merger history of…
We present new results on the angular momentum evolution of dark matter halos. Halos, from N-body simulations, are classified according to their mass growth histories into two categories: the accretion category contains halos whose mass has…
We follow the spin vector evolutions of well resolved dark matter haloes (containing more than 300 particles) in merger tree main branches from the Millennium and Millennium-II N-body simulations, from z about 3.3 to z = 0. We find that…
We have made a detailed comparison of the results of large N-body simulations with the analytical description of the merging histories of dark matter halos presented in Lacey & Cole 1993, which is based on an extension of the Press-…
We use N-body simulations to investigate the evolution of the orientation and magnitude of dark matter halo angular momentum within the large scale structure since z=3. We look at the evolution of the alignment of halo spins with filaments…
We expand our previous study on the relationship between changes in the orientation of the angular momentum vector of dark matter haloes ("spin flips") and changes in their mass (Bett & Frenk 2012), to cover the full range of halo masses in…
The spin, $\lambda$, of dark matter (DM) halos in cosmological simulations follows a log normal distribution and has little correlation with galaxy observables. As such, there is currently no way to infer the $\lambda$ parameter of…
We present a model for the dynamical evolution of subhaloes based on an approach combining numerical and analytical methods. Our method is based on tracking subhaloes in an N-body simulation up to the last point that it can be resolved, and…
A recent study conducted using CALIFA survey data (Lee et al, 2019b) has found that the orbital motions of neighbor galaxies are coherent with the spin direction of a target galaxy on scales of many Megaparsecs. We study this so called…
Predicting the merger timescale ($\tau_{\rm merge}$) of merging dark matter halos, based on their orbital parameters and the structural properties of their hosts, is a fundamental problem in gravitational dynamics that has important…