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Galaxies: kinematics and dynamics

Department of Physics and Astronomy Faculty Publications

Articles 1 - 2 of 2

Full-Text Articles in Astrophysics and Astronomy

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 …


Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller Jan 2006

Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller

Department of Physics and Astronomy Faculty Publications

Evolution of stellar bars in disk galaxies is accompanied by dynamical instabilities and secular changes. Following the vertical buckling instability, the bars are known to weaken dramatically and develop a pronounced boxy/ peanut shape when observed edge-on. Using high-resolution N-body simulations of stellar disks embedded in live axisymmetric dark matter halos, we have investigated the long-term changes in the bar morphology, specifically the evolution of the bar size, its vertical structure, and the exchange of angular momentum. We find that following the initial buckling, the bar resumes its growth from deep inside the corotation radius and follows the ultraharmonic resonance …