Revisiting the Galaxy Shape and Spin Alignments with the Large-Scale
  Tidal Field: An Effective Practical Model
  An effective practical model with two characteristic parameters is presented
to describe both of the tidally induced shape and spin alignments of the
galactic halos with the large-scale tidal fields. We test this model against
the numerical results obtained from the Small MultiDark Planck simulation on
the galactic mass scale of $0.5\le M/(10^{11}\,h^{-1}\,M_{\odot})\le 50$ at
redshift $z=0$. Determining empirically the parameters from the numerical data,
we demonstrate how successfully our model describes simultaneously and
consistently the amplitudes and behaviors of the probability density functions
of three coordinates of the shape and spin vectors in the principal frame of
the large scale tidal field. Dividing the samples of the galactic halos into
multiple subsamples in four different mass ranges and four different types of
the cosmic web, and also varying the smoothing scale of the tidal field from
$5\,h^{-1}$Mpc to $10,\ 20,\ 30\,h^{-1}$Mpc, we perform repeatedly the
numerical tests with each subsample at each scale. Our model is found to match
well the numerical results for all of the cases of the mass range, smoothing
scale and web type and to properly capture the scale and web dependence of the
spin flip phenomenon.
