The evolution and distribution of the angular momentum of dark matter (DM) halos have been discussed in several studies over the past decades. In particular, the idea arose that angular momentum conservation should allow to infer the total angular momentum of the entire DM halo from measuring the angular momentum of the baryonic component, which is populating the center of the halo, especially for disk galaxies. To test this idea and to understand the connection between the angular momentum of the DM halo and its galaxy, we use the Magneticum simulations. We successfully produce populations of spheroidal and disk galaxies self-consistently. Thus, we are able to study the dependence of galactic properties on their morphology. We find that (1) the specific angular momentum of stars in disk and spheroidal galaxies as a function of their stellar mass compares well with observational results; (2) the specific angular momentum of the stars in disk galaxies is slightly smaller compared to the specific angular momentum of the cold gas, in good agreement with observations; (3) simulations including the baryonic component show a dichotomy in the specific stellar angular momentum distribution when splitting the galaxies according to their morphological type (this dichotomy can also be seen in the spin parameter, where disk galaxies populate halos with slightly larger spin compared to spheroidal galaxies); (4) disk galaxies preferentially populate halos in which the angular momentum vector of the DM component in the central part shows a better alignment to the angular momentum vector of the entire halo; and (5) the specific angular momentum of the cold gas in disk galaxies is approximately 40 percent smaller than the specific angular momentum of the total DM halo and shows a significant scatter.
Connecting the new H.E.S.S. diffuse emission at the Galactic center with the Fermi GeV excess: a combination of millisecond pulsars and heavy dark matter?
Galaxy shapes in Magneticum. I. Connecting stellar and dark matter shapes to dynamical and morphological galaxy properties and the large-scale structure
Connecting galaxies with their haloes -- from parsec to Mpc scales
University of Vienna（维也纳大学）；University of New South Wales（新南威尔士大学）；Indian Institute of Astrophysics（印度天体物理研究所）；Instituto de Astrofı́sica de Canarias（加那利天体物理学研究所）；Universidad de La Laguna（拉古纳大学）；Centre for Astrophysics and Supercomputing, Swinburne University（斯威本大学天体物理学与超级计算中心）；European Southern Observatory（欧洲南方天文台）；University of Queensland（昆士兰大学）；University of Turku（图尔库大学）；Leiden Observatory（莱顿天文台）；Delft University（代尔夫特理工大学）；Heidelberg University（海德堡大学）
The incidence and star-formation properties of X-ray active galactic nuclei across the star-forming main sequence in DESI-eRASS1: the role of host-galaxy morphology
Instituto de Fisica de Cantabria (CSIC-Universidad de Cantabria)（坎塔布里亚物理研究所（西班牙科学研究中心-坎塔布里亚大学））；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；Departamento de Astrofísica, Universidad de La Laguna（拉帕尔马大学天体物理学系）
