The SAMI Galaxy Survey: First detection of a transition in spin
  orientation with respect to cosmic filaments in the stellar kinematics of
  galaxies
  We present the first detection of mass dependent galactic spin alignments
with local cosmic filaments with over 2 sigma confidence using IFS kinematics.
The 3D network of cosmic filaments is reconstructed on Mpc scales across GAMA
fields using the cosmic web extractor DisPerSe. We assign field galaxies from
the SAMI survey to their nearest filament segment in 3D and estimate the degree
of alignment between SAMI galaxies kinematic spin axis and their nearest
filament in projection. Low-mass galaxies align their spin with their nearest
filament while higher mass counterparts are more likely to display an
orthogonal orientation. The stellar transition mass from the first trend to the
second is bracketed between log stellar masses 10.4 and 10.9, with hints of an
increase with filament scale. Consistent signals are found in the HorizonAGN
cosmological hydrodynamic simulation. This supports a scenario of early angular
momentum build-up in vorticity rich quadrants around filaments at low stellar
mass followed by progressive flip of spins orthogonal to the cosmic filaments
through mergers at high stellar mass. Conversely, we show that dark-matter only
simulations post-processed with a semi-analytic model treatment of galaxy
formation struggles to reproduce this alignment signal. This suggests that gas
physics is key in enhancing the galaxy-filament alignment.
