منابع مشابه
Infall Caustics in Dark Matter Halos?
We show that most particle and subhalo orbits in simulated cosmological cold dark matter halos are surprisingly regular and periodic: The phase space structure of the outer halo regions shares some of the properties of the classical self-similar secondary infall model. Some of the outer branches are clearly visible in the radial velocity radius plane at certain epochs. However, they are severel...
متن کاملDark Matter Halos in a Secondary Infall Model
We calculate the density profiles of virialized halos in the case of structure evolving hierarchically from a scale-free Gaussian δ−field having a power spectrum P (k) ∝ kn in a Ω = 1 Universe; we suppose that the initial density contrast profile around local maxima is given by the mean peak profile introduced by Bardeen et al. (1986 hereafter BBKS). We show both that the density profiles are n...
متن کاملThe Inner Caustics of Cold Dark Matter Halos
Abstract We prove that a flow of cold collisionless particles from all directions in and out of a region necessarily forms a caustic. A corollary is that, in cold dark matter cosmology, galactic halos have inner caustics in addition to the more obvious outer caustics. The outer caustics are fold catastrophes located on topological spheres surrounding the galaxy. To obtain the catastrophe struct...
متن کاملThe Compression of Dark Matter Halos by Baryonic Infall
The initial radial density profiles of dark matter halos are laid down by gravitational collapse in hierarchical structure formation scenarios and are subject to further compression as baryons cool and settle to the halo centers. Here we describe an explicit implementation of the algorithm, originally developed by Young, to calculate changes to the density profile as the result of adiabatic inf...
متن کاملDark matter caustics.
The late infall of cold dark matter onto an isolated galaxy such as our own produces flows with definite velocity vectors at any physical point in the galactic halo. It also produces caustics which are places where the dark matter density is very large. The outer caustics are topological spheres whereas the inner caustics are rings. The self-similar model of galactic halo formation predicts tha...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2008
ISSN: 0004-637X,1538-4357
DOI: 10.1086/589688