Virial Clumps in Central Molecular Zone Clouds
  CMZoom survey observations with the Submillimeter Array are analyzed to
describe the virial equilibrium (VE) and star-forming potential of 755 clumps
in 22 clouds in the Central Molecular Zone (CMZ) of the Milky Way. In each
cloud, nearly all clumps follow the column-density-mass trend N~M^s, where s =
0.38 +- 0.03 is near the pressure-bounded limit s=1/3. This trend is expected
when gravitationally unbound clumps in VE have similar velocity dispersion and
external pressure. Nine of these clouds also harbor one or two distinctly more
massive clumps. These properties allow a VE model of bound and unbound clumps
in each cloud, where the most massive clump has the VE critical mass. These
models indicate that 213 clumps have velocity dispersion 1-2 km s^(-1), mean
external pressure 0.5-4 x 10^8 cm^(-3) K, bound clump fraction 0.06, and
typical virial parameter alpha=4-15. These mostly unbound clumps may be in VE
with their turbulent cloud pressure, possibly driven by inflow from the
galactic bar. In contrast, most Sgr B2 clumps are bound according to their
associated sources and N-M trends. When the CMZ clumps are combined into mass
distributions, their typical power-law slope is analyzed with a stopped
accretion model. It also indicates that most clumps are unbound and cannot grow
significantly, due to their similar time scales of accretion and dispersal,
~0.2 Myr. Thus, virial and dynamical analyses of the most extensive clump
census available indicate that star formation in the CMZ may be suppressed by a
significant deficit of gravitationally bound clumps.
