English

Observational detection of correlation between galaxy spins and initial conditions

Cosmology and Nongalactic Astrophysics 2020-12-14 v1 Astrophysics of Galaxies

Abstract

Galaxy spins can be predicted from the initial conditions in the early Universe through the tidal tensor twist. In simulations, their directions are well preserved through cosmic time, consistent with expectations of angular momentum conservation. We report a 3σ\sim 3 \sigma detection of correlation between observed oriented directions of galaxy angular momenta and their predictions based on the initial density field reconstructed from the positions of SDSS galaxies. The detection is driven by a group of spiral galaxies classified by the Galaxy Zoo as (anti-)clockwise, with a modest improvement from adding galaxies from MaNGA and SAMI surveys. This is the first such detection of the oriented galaxy spin direction, which opens a way to use measurements of galaxy spins to probe fundamental physics in the early Universe.

Keywords

Cite

@article{arxiv.2003.04800,
  title  = {Observational detection of correlation between galaxy spins and initial conditions},
  author = {Pavel Motloch and Hao-Ran Yu and Ue-Li Pen and Yuanbo Xie},
  journal= {arXiv preprint arXiv:2003.04800},
  year   = {2020}
}

Comments

6 pages, 6 figures

R2 v1 2026-06-23T14:10:21.439Z