Year: 2018
Type: article
Abstract: Selecting disk galaxies from the cosmological, hydrodynamical simulation Magneticum Pathfinder, we show that almost half of our poster child disk galaxies at z = 2 show significantly declining rotation curves and low dark matter fractions, very similar to recently reported observations. These galaxies do not show any anomalous behavior, they reside in standard dark matter halos, and they typically grow significantly in mass until z = 0, where they span all morphological classes, including disk galaxies matching present-day rotation curves and observed dark matter fractions. Our findings demonstrate that declining rotation curves and low dark matter fractions in rotation-dominated galaxies at z = 2 appear naturally within the ΛCDM paradigm and reflect the complex baryonic physics, which plays a role at the peak epoch of star formation. In addition, we find some dispersion-dominated galaxies at z = 2 that host a significant gas disk and exhibit similar shaped rotation curves as the disk galaxy population, rendering it difficult to differentiate between these two populations with currently available observation techniques.
Authors: Adelheid F. Teklu, Rhea-Silvia Remus, Klaus Dolag, Alexander Arth, Andreas Burkert, Aura Obreja, Felix Schulze
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G2865679910, G3814729504, G5598661011
OpenAlex ID: W2787671113