Modeling the phase-space distribution around massive halos
نویسندگان
چکیده
منابع مشابه
modeling loss data by phase-type distribution
بیمه گران همیشه بابت خسارات بیمه نامه های تحت پوشش خود نگران بوده و روش هایی را جستجو می کنند که بتوانند داده های خسارات گذشته را با هدف اتخاذ یک تصمیم بهینه مدل بندی نمایند. در این پژوهش توزیع های فیزتایپ در مدل بندی داده های خسارات معرفی شده که شامل استنباط آماری مربوطه و استفاده از الگوریتم em در برآورد پارامترهای توزیع است. در پایان امکان استفاده از این توزیع در مدل بندی داده های گروه بندی ...
Phase-Space Evolution of Dark Matter Halos
Context. In a Universe dominated by dark matter, halos are continuously accreting mass (violently or not) and such mechanism affects their dynamical state. Aims. The evolution of dark matter halos in phase-space, and using the phase-space density indicator Q = ρ/σ as a tracer, is discussed. Methods. We have performed cosmological N-body simulations from which we have carried a detailed study of...
متن کاملPhase - Space Structure & Substructure of Dark Halos
A method is presented for computing the 6-D phase-space density f(x,v) and its PDF v(f) in an N-body system. It is based on Delaunay tessellation, yielding v(f) with a fixed smoothing window over a wide f range, independent of the sampling resolution. It is found that in a gravitationally relaxed halo built by hierarchical clustering, v(f) is a robust power law, v(f) ∝ f−2.5±0.05, over more tha...
متن کاملCosmology with the Space-Luminosity Distribution of Virialized Halos
We derive the observed luminosity function of virialized systems. Coupling this statistic with the mass function predicted by CDM cosmogonies we obtain the functional behavior of the mass–to–light ratio over a wide dynamical range in mass. We conclude that the mass–to–light ratio has a minimum close to the luminosity of an L∗ galaxy halo. We also show how to derive in a self-consistent way the ...
متن کاملThe Phase-Space Density Profiles of Cold Dark Matter Halos
We examine the coarse-grained phase-space density profiles of a set of recent, highresolution simulations of galaxy-sized Cold Dark Matter (CDM) halos. Over two and a half decades in radius the phase-space density closely follows a power-law, ρ/σ ∝ r−α, with α ≈ 1.875. This behaviour closely matches the self-similar solution obtained by Bertschinger for secondary infall of gas onto a point-mass...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 2013
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.88.023012