A large catalogue of molecular clouds with accurate distances within 4
  kpc of the Galactic disk
  We present a large, homogeneous catalogue of molecular clouds within 4 kpc
from the Sun at low Galactic latitudes ($|b|$ $<$ 10\degr) with unprecedented
accurate distance determinations. Based on the three-dimensional dust reddening
map and estimates of colour excesses and distances of over 32 million stars
presented in Chen et al, we have identified 567 dust/molecular clouds with a
hierarchical structure identification method and obtained their distance
estimates by a dust model fitting algorithm. The typical distance uncertainty
is less than 5 per cent. As far as we know, this is the first large catalogue
of molecular clouds in the Galactic plane with distances derived in a direct
manner. The clouds are seen to lie along the Sagittarius, Local and Perseus
Arms. In addition to the known structures, we propose the existence of a
possible {\it spur}, with a pitch angle of about 34\degr, connecting the Local
and the Sagittarius Arms in the fourth quadrant. We have also derived the
physical properties of those molecular clouds. The distribution of cloud
properties in different parameter spaces agrees grossly with the previous
results. Our cloud sample is an ideal starting point to study the concentration
of dust and gas in the solar vicinity and their star formation activities.
