http://arxiv.org/abs/2004.02638
The galaxy spin flip refers to the phenomenon that the spin axes of galaxies with masses above a certain threshold tend to be preferentially aligned perpendicular to the hosting large-scale filaments, while low mass or early type galaxies tend to have their spin axes aligned parallel to such structures. Extensive work has so far been conducted to understand this phenomenon under the assumption of cold dark matter and suggested that its origin should be closely related to the nonlinear evolution of the galaxy angular momentum in the anisotropic cosmic web. We present, for the first time, a numerical examination of this phenomenon assuming the presence of massive neutrinos, finding a clear and robust dependence of the threshold mass for the spin flip on the total neutrino mass. Our physical explanation is that the presence of more massive neutrinos retard the nonlinear evolution of the cosmic web, which in turn allows the galaxy spin vectors to better retain their memories of the initial tidal interactions even in the highly nonlinear regime. Our finding in principle implies that the statistical alignment of galaxy spins with the large-scale structures can be used as a probe of the total neutrino mass.
J. Lee, N. Libeskind and S. Ryu
Tue, 7 Apr 20
23/72
Comments: 5 pages, 7 figures, comments welcome
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