  The correlation between the spins of dark matter halos and the large-scale
structure (LSS) has been studied in great detail over a large redshift range,
while investigations of galaxies are still incomplete. Motivated by this point,
we use the state-of-the-art hydrodynamic simulation, Illustris-1, to
investigate mainly the spin--LSS correlation of galaxies at redshift of $z=0$.
We mainly find that the spins of low-mass, blue, oblate galaxies are
preferentially aligned with the slowest collapsing direction ($e_3$) of the
large-scale tidal field, while massive, red, prolate galaxy spins tend to be
perpendicular to $e_3$. The transition from a parallel to a perpendicular trend
occurs at $\sim10^{9.4} M_{\odot}/h$ in the stellar mass, $\sim0.62$ in the g-r
color, and $\sim0.4$ in triaxiality. The transition stellar mass decreases with
increasing redshifts. The alignment was found to be primarily correlated with
the galaxy stellar mass. Our results are consistent with previous studies both
in N-body simulations and observations. Our study also fills the vacancy in the
study of the galaxy spin--LSS correlation at $z=0$ using hydrodynamical
simulations and also provides important insight to understand the formation and
evolution of galaxy angular momentum.
