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Full-Text Articles in Physical Sciences and Mathematics

Erasing Dark Matter Cusps In Cosmological Galactic Halos With Baryons, Emilio Romano-Diaz, Isaac Shlosman, Yehuda Hoffman, Clayton Heller Oct 2008

Erasing Dark Matter Cusps In Cosmological Galactic Halos With Baryons, Emilio Romano-Diaz, Isaac Shlosman, Yehuda Hoffman, Clayton Heller

Department of Physics and Astronomy Faculty Publications

We study the central dark matter (DM) cusp evolution in cosmologically grown galactic halos. Numerical models with and without baryons (baryons+DM, hereafter BDM model, and pure DM, PDM model, respectively) are advanced from identical initial conditions, obtained using the Constrained Realization method. The DM cusp properties are contrasted by a direct comparison of pure DM and baryonic models. We find a divergent evolution between the PDM and BDM models within the inner few × 10 kpc region. The PDM model forms an R−1 cusp as expected, while the DM in the BDM model forms a larger isothermal cusp R …


Dark Side Of The Universe: Dark Matter In The Galaxy And Cosmos, Shane L. Larson Aug 2008

Dark Side Of The Universe: Dark Matter In The Galaxy And Cosmos, Shane L. Larson

Public Talks

No abstract provided.


Noise-Driven Evolution In Stellar Systems: Theory, Martin D. Weinberg Jan 2008

Noise-Driven Evolution In Stellar Systems: Theory, Martin D. Weinberg

Astronomy Department Faculty Publication Series

We present a theory for describing the evolution of a galaxy caused by stochastic events such as weak mergers, transient spiral structure, orbiting blobs, etc. This noise excites large-scale patterns that drives the evolution of the galactic density profile. In dark-matter haloes, the repeated stochastic perturbations preferentially ring the lowest-order modes of the halo with only a very weak dependence on the details of their source. Shaped by these modes, the profile quickly takes on a nearly self-similar form. We show that this form has the features of the “universal profile” reported by Navarro, Frenk, & White independent of initial …


Quantum Condensates In Extreme Gravity: Implications For Cold Stars And Dark Matter [Post-Print], Mark P. Silverman Jan 2008

Quantum Condensates In Extreme Gravity: Implications For Cold Stars And Dark Matter [Post-Print], Mark P. Silverman

Faculty Scholarship

Stable end-point stars currently fall into two distinct classes — white dwarfs and neutron stars — differing enormously in central density and radial size. No stable cold dead stars are thought to span the intervening densities or have masses beyond ~2–3 solar masses. I show, however, that the general-relativistic condition of hydrostatic equilibrium augmented by the equation of state of a neutron condensate at 0 K generates stable sequences of cold stars that span the density gap and can have masses well beyond prevailing limits. The radial sizes and mass limit of each sequence are determined by the mass and …