Radial Distributions of Surface Mass Density and Mass-to-Luminosity
  Ratio in Spiral Galaxies
  We present radial profiles of the surface mass density (SMD) in spiral
galaxies directly calculated using rotation curves (RC) on two approximations
of flat-disk (SMD-F) and spherical mass distribution (SMD-S). The SMDs are
combined with surface brightness (SB) using photometric data to derive radial
variations of the mass-to-luminosity ratio (ML). It is found that ML has
generally a central peak or a plateau, and decreases to a local minimum at
$R\sim 0.1-0.2 h$, where $R$ is the radius and $h$ is the scale radius of
optical disk. The ML ratio, then, increases rapidly till $\sim 0.5h$, and is
followed by gradual rise till $\sim 2h$, remaining at around ML$\sim 2$ in w1
band (infrared $\lambda$ 3.4 $\mu$m) and $\sim 10\ [M_\odot L_\odot^{-1}]$ in
r-band ($\lambda$6200-7500 A). Beyond this radius, ML steeply increases toward
the observed edges at $R\sim 5h$, attaining values as high as ML$\sim 20$ in w1
and $\sim 10^2\ [M_\odot L_\odot^{-1}]$ in r-band, indicative of dominant dark
matter. The general properties of the ML distributions will be useful to
constrain cosmological formation models of spiral galaxies. The radial profiles
of the RC, SMD, and ML are available in pdf/eps figures and machine-readable
tables as an archival atlas at URL
http://www.ioa.s.u-tokyo.ac.jp/$\sim$sofue/smd2018/ and as the supplementary
data on PASJ home page.
