Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
Structure Formation Inside Triaxial Dark Matter Halos: Galactic Disks, Bulges, And Bars, Clayton Heller, Isaac Shlosman, Evangelie Athanassoula
Structure Formation Inside Triaxial Dark Matter Halos: Galactic Disks, Bulges, And Bars, Clayton Heller, Isaac Shlosman, Evangelie Athanassoula
Department of Physics and Astronomy Faculty Publications
We investigate formation and evolution of galactic disks immersed in assembling live DM halos. Models have been evolved from cosmological initial conditions and represent the collapse of an isolated density perturbation. The baryons include gas participating in star formation (SF) and stars with the energy feedback onto the ISM. We find that (1) the triaxial halo figure tumbling is insignificant and the angular momentum (J) is channeled into the internal circulation, while the baryonic collapse is stopped by the centrifugal barrier; (2) density response of the (disk) baryons is out of phase with DM, thus washing out the …
Gas Feedback On Stellar Bar Evolution, Ingo Berentzen, Isaac Shlosman, Inma Martinez-Valpuesta, Clayton Heller
Gas Feedback On Stellar Bar Evolution, Ingo Berentzen, Isaac Shlosman, Inma Martinez-Valpuesta, Clayton Heller
Department of Physics and Astronomy Faculty Publications
We analyze evolution of live disk-halo systems with gas fractions, fgas ≤ 8% of the disk mass, for 5 Gyr. Specifically, we have addressed the issue of angular momentum (J) transfer from the gas to the stellar bar and its effect on the bar. We find that the bar weakening, reported in the literature, is not related to the gas, but is caused by the vertical buckling instability in the gas-poor disks and by a steep stellar heating by the central mass concentration (CMC) in the gas-rich disks. However, the gas has a profound effect on the …
Induced Nested Galactic Bars Inside Assembling Dark Matter Halos, Clayton Heller, Isaac Shlosman, Evangelie Athanassoula
Induced Nested Galactic Bars Inside Assembling Dark Matter Halos, Clayton Heller, Isaac Shlosman, Evangelie Athanassoula
Department of Physics and Astronomy Faculty Publications
We investigate the formation and evolution of nested bar systems in disk galaxies in a cosmological setting by following the development of an isolated dark matter (DM) and baryon density perturbation. The disks form within the assembling triaxial DM halos, and the feedback from the stellar evolution is accounted for in terms of supernovae and OB stellar winds. Focusing on a representative model, we show the formation of an oval disk and of a first generation of nested bars with characteristic subkiloparsec sizes and a few kiloparsec sizes. The system evolves through successive dynamical couplings and decouplings, forcing the gas …