Propagation of Highly Efficient Star Formation in NGC 7000
  We surveyed the (1,1), (2,2), and (3,3) lines of NH3 and the H2O maser toward
the molecular cloud L935 in the extended HII region NGC 7000 with an angular
resolution of 1.6' using the Kashima 34-m telescope. We found five clumps in
the NH3 emission with a size of 0.2--1 pc and mass of 9--452 M_sun. The
molecular gas in these clumps has a similar gas kinetic temperature of 11--15 K
and a line width of 1--2 km/s. However, they have different star formation
activities such as the concentration of T-Tauri type stars and the association
of H2O maser sources. We found that these star formation activities are related
to the geometry of the HII region. The clump associated with the T-Tauri type
star cluster has a high star formation efficiency of 36--62%. This clump is
located near the boundary of the HII region and molecular cloud. Therefore, we
suggest that the star formation efficiency increases because of the triggered
star formation.
