The old moving groups in the field of Taurus
  In this work, we present a systematic search for stellar groups in the Taurus
field by applying DBSCAN algorithm to the data from Gaia DR2. We find 22
groups, consisting of 8 young groups (Groups 1-8) at ages of 2-4Myr and
distances of ~130-170pc, 14 old groups (Groups 9-22) at ages of 8-49Myr and
distances of ~110-210pc. We characterize the disk properties of group members
and find 19 new disk-bearing stars, 8 of which are in the young groups and 11
others belong to the comparatively old groups at ages of 8-11 Myr. We
characterize the accretion properties of the group members with H$\alpha$
emission line in their LAMOST spectra, and discover one source in Group 10 at
an age of 10 Myr which still shows accretion activity. We investigate the
kinematic relations among the old groups, and find that Group 9 is
kinematically related to the known Taurus members and exclude any kinematic
relations between Groups 10-22 and the known Taurus members.
