Extreme kinematic misalignment in IllustrisTNG galaxies: the origin, structure, and internal dynamics of galaxies with a large-scale counterrotation
Year: 2020
Type: article
Abstract: ABSTRACT We provide an in-deep analysis of 25 galaxies with substantial counterrotation from IllustrisTNG100 simulations in the stellar mass range 2×109−3×1010 M⊙. The counterrotation is a result of an external gas infall ≈2–8 Gyr ago. The infall leads to the removal of pre-existing gas, which is captured and mixed together with the infalling component. This mixture ends up in the counterrotating gaseous disc where ${\approx}90{{\ \rm per\ cent}}$ of counterrotating stars formed in-situ. During the early phases of the infall, gas can be found in extended structures which, in some galaxies, are similar to (nearly-) polar ring-like components. We suggest that the AGN activity does not cause the counterrotation, although it is efficiently triggered by the retrograde gas infall, and it correlates well with the misaligned component appearance. We also find the vertical-to-radial velocity dispersion ratio above unity implying the importance of misalignment in shaping the velocity ellipsoids.
Institutions: Russian Academy of Sciences, Leibniz Institute for Astrophysics Potsdam, Max Planck Institute for Extraterrestrial Physics, Institute of Astronomy, National Academy of Sciences of Ukraine, Main Astronomical Observatory, Ludwig-Maximilians-Universität München, Heidelberg University, Volgograd State University, Chinese Academy of Sciences, National Astronomical Observatories, Lomonosov Moscow State University, Excellence Cluster Universe, New Mexico State University, Special Astrophysical Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: Robert Sterling Clark Foundation, California Department of Fish and Game, Deutsche Forschungsgemeinschaft, Universität Heidelberg, Volkswagen Foundation, National Natural Science Foundation of China, Russian Foundation for Basic Research, Chinese Academy of Sciences, National Academy of Sciences of Ukraine, Russian Science Foundation, Ministry of Science and Higher Education of the Russian Federation, Lomonosov Moscow State University, National Astronomical Observatories, Chinese Academy of Sciences
OpenAlex ID: W3094480976