Evidence for spin alignment of spiral and elliptical/S0 galaxies in
  filaments
  Galaxies are not distributed randomly in the cosmic web but are instead
arranged in filaments and sheets surrounding cosmic voids. Observationally
there is still no convincing evidence of a link between the properties of
galaxies and their host structures. However, by the tidal torque theory (our
understanding of the origin of galaxy angular momentum), such a link should
exist. Using the presently largest spectroscopic galaxy redshift survey (SDSS)
we study the connection between the spin axes of galaxies and the orientation
of their host filaments.
  We use a three dimensional field of orientations to describe cosmic
filaments. To restore the inclination angles of galaxies, we use a 3D
photometric model of galaxies that gives these angles more accurately than
traditional 2D models.
  We found evidence that the spin axes of bright spiral galaxies have a weak
tendency to be aligned parallel to filaments. For elliptical/S0 galaxies, we
have a statistically significant result that their spin axes are aligned
preferentially perpendicular to the host filaments; we show that this signal
practically does not depend on the accuracy of the estimated inclination angles
for elliptical/S0 galaxies.
