2020/07/26 by E. Ebrahimian, A. A. Abolhasani
Physics and Astronomy · #Astronomy and Astrophysical Research #Cold dark matter #Dark Matter and Cosmic Phenomena #Dark matter #Dark matter halo #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Hot dark matter #Scalar field dark matter #Spin (aerodynamics) #Spins #astro-ph.CO #gr-qc
paper · pdf · doi:10.3847/1538-4357/abd6eb
7 pages, 3 figures
arxiv created 2020/07/26 · openalex created_date 2020/07/29 · openalex publication_date 2021/05/01 · arxiv updated 2021/05/12 · openalex updated_date 2026/08/05
Abstract We revisit the question of what mechanism is responsible for the spins of halos of dark matter. The answer to this question is of high importance for modeling galaxy intrinsic alignment, which can potentially contaminate current and future lensing data. In particular, we show that when the dark matter halos pass nearly each other in dense environments—namely halo assemblies—they swing and spin each other via exerting mutual tidal torques. We show that this has a significant contribution to the spin of dark matter halos comparable to that calculated by the so-called tidal torque theory. We use the results of the state-of-the-art simulation of Illutris to check the prediction of this theory against the simulation data.