http://arxiv.org/abs/2305.04409
In the linear theory, the galaxy angular momentum vectors which originate from the initial tidal interactions with surrounding matter distribution intrinsically develop perpendicular alignments with the directions of maximum matter compression, regardless of galaxy mass. In simulations, however, the galaxy spins exhibit parallel alignments in the mass-range lower than a certain threshold, which depends on redshift, web type, and background cosmology. We show that the observed three dimensional spins of the spiral galaxies located on the void surfaces from the Sloan Digital Sky Survey indeed transit from the perpendicular to the parallel alignments with the directions toward the void centers at the threshold zone, $9.51\le\log (M_{\star}/h^{-1}\,M_{\odot})\le10.03$. The null hypothesis of no spin transition is rejected at the 99.9% confidence level by the Kolmogorov-Smirnov test. This study presents a first direct observational evidence for the occurrence of the mass-dependent spin transition of the real galaxies with respect to the non-filamentary structures of the cosmic web, opening a way to constrain the initial conditions of the early universe by measuring the spin transition threshold.
J. Lee and J. Moon
Tue, 9 May 23
77/88
Comments: 4 figures, comments well come