Spatially Resolved Galaxy Angular Momentum
- 1. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, Australia
- 2. International Centre for Radio Astronomy Research, University of Western Australia, 7 Fairway, Crawley, WA 6009, Australia
The total specific angular momentum j of a galaxy disk is matched with that of its dark matter halo, but the distributions are different, in that there is a lack of both low- and high-j baryons with respect to the CDM predictions. We illustrate how the probability distribution function pdf(j) can inform us of a galaxy's morphology and evolutionary history with a spanning set of examples from present-day galaxies and a galaxy at z~1.5. The shape of pdf(j) is correlated with photometric morphology, with disk-dominated galaxies having more symmetric pdf(j) and bulge-dominated galaxies having a strongly-skewed pdf(j). Galaxies with bigger bulges have more strongly-tailed \pdf(j), but disks of all sizes have a similar pdf(j). In future, pdf(j) will be useful as a kinematic decomposition tool.