2018/08/19 by Sarah M. Sweet, Sweet, Sarah M., Deanne B. Fisher +9
Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.1808.06269
Invited feature talk at IAU Focus Meeting 6; to appear in proceedings Astronomy in Focus
arxiv created 2018/08/19 · arxiv updated 2018/08/21
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. I illustrate how the probability density function PDF(j/jmean) 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/jmean) is correlated with photometric morphology, with disk-dominated galaxies having more symmetric PDF(j/jmean) and bulge-dominated galaxies having a strongly-skewed PDF(j/jmean). Galaxies with bigger bulges have more strongly-tailed PDF(j/jmean), but disks of all sizes have a similar PDF(j/jmean). In future, PDF(j/jmean) will be useful as a kinematic decomposition tool.