PROFESSOR ARI MALLER

Angular momentum plays an important role determining the sizes of disk galaxies. However, galaxies contain only a small fraction of the baryons available to them. Thus, the specific angular momentum of galaxies should not be the same as dark matter halos. Looking at hydrodynamical simulations, the speaker will show that specific angular momentum grows over cosmological time. In addition, cold flow gas has higher specific angular momentum than other gas or dark matter. The result of this is a cold flow disk that can extend as far as 50 – 100 kpc around galaxies, and gives rise to QSO absorption systems. The sizes of galaxy disks are, thus, strongly dependent on what gas they form from.