Assigned ID: 106 ----- Submission 1 (Thu Jan 20 22:20:28 GMT 2005) ----- We propose to use a new diagnostic tool to study the mass buildup in disk galaxies as a function of look-back time out to z~1. The tight correlation between spiral arm pitch angle and rotation curve shear rate (Seigar et al. 2005) demonstrates that the tightness of spiral structure in disk galaxies depends on the central mass concentration (including dark matter), as this determines the shear rate. Galaxies with high central mass concentration have a higher shear rate and more tightly wound spiral structure than those with low mass concentration. As a result, the evolution of spiral structure over time can be used to search for evolution in the mass distribution in spiral galaxies. The main goal of this project is to determine evolution in the mass distribution of disk galaxies, using spiral arm pitch angles as a quanitative indicator. In order to do this we will use nearly face-on disk galaxies with measurable spiral structure, observed in the GOODS fields.

COSMOLOGY 12 92699 false 0.0 false false false false false SUPPORTED