FORMATION OF GLOBULAR-CLUSTERS FROM GAS IN LARGE-SCALE UNORGANIZED MOTION IN GALAXIES

From dynamical data on interstellar gas and gobular clusters with ages of 5 x 10(6)-10(10) yr in the Magellanic Clouds, it is claimed that globular clusters may be generated at any time in any galaxy, if interstellar ps clouds are in large-scale unorganized motion with velocity of more than 50-100 km s-1 and they collide with each other to make strong local shock compressions. Dynamical and optical characteristics of globular clusters are explained to be consistent with this mechanism in the Galaxy, the Magellanic Clouds, M31, M33, M82, M87, NGC 1275, and other nearby galaxies. Theories are surveyed to produce a grand scenario that (1) the minimum mass of the Jeans gravitational instability is 10(4)-10(6) M. for gas compressed by collision of clouds with velocity of greater-than-or-equal-to 50-100 km s-1, (2) low-mass stars are more numerously and more quickly formed near the protoglobular cluster center, and that (3) this stellar system is gravitationally stable against the blow-out of gas by newborn stars and/or by supernovae, which results in the delayed appearance of the cluster formation. We also suggest that more massive globular clusters are formed from gases with lower metal abundance and in higher velocity collision.