Connecting Galaxy Disk and Extended Halo Gas Kinematics
Abstract
We have explored the galaxy disk/extended halo gas kinematic relationship using rotation curves (Keck/ESI) of ten intermediate redshift galaxies which were selected by MgII halo gas absorption observed in quasar spectra. Previous results of six edge-on galaxies, probed along their major axis, suggest that observed halo gas velocities are consistent with extended disk-like halo rotation at galactocentric distances of 25-72 kpc. Using our new sample, we demonstrate that the gas velocities are by and large not consistent with being directly coupled to the galaxy kinematics. Thus, mechanisms other than co-rotation dynamics (i.e., gas inflow, feedback, galaxy-galaxy interactions, etc.) must be invoked to account for the overall observed kinematics of the halo gas. In order to better understand the dynamic interaction of the galaxy/halo/cosmic web environment, we performed similar mock observations of galaxies and gaseous halos in Lambda-CDM cosmological simulations. We discuss an example case of a z=0.92 galaxy with various orientations probing halo gas at a range of positions. The gas dynamics inferred using simulated quasar absorption lines are consistent with observational data.
Keywords
Cite
@article{arxiv.0710.4962,
title = {Connecting Galaxy Disk and Extended Halo Gas Kinematics},
author = {G. G. Kacprzak and C. W. Churchill and C. C. Steidel and D. Ceverino and A. A. Klypin and M. T. Murphy},
journal= {arXiv preprint arXiv:0710.4962},
year = {2007}
}
Comments
To appear in the proceedings of "The Formation and Evolution of Galaxy Disks", Rome 2007, organized by the Vatican Observatory, editors J. G. Funes, S.J. and E. M. Corsini