Observational detection of correlation between galaxy spins and initial conditions

Understand

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 $\sim 3 \sigma$ 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.