|Authors||Keith M. Ashman (1), Stephen E. Zepf (2)|
|Affiliation||1 Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 |
and Department of Physics, Baker University, Baldwin, KS 66006;
2 Department of Astronomy, Yale University, New Haven, CT 06520
|Accepted by||Astronomical Journal|
We also note that the apparent lack of a mass-radius relationship in young and old globular cluster systems places important constraints on globular cluster formation models. This is because molecular clouds are observed to follow a virial scaling relation between mass and radius.
We suggest that a variable star formation efficiency may weaken or eliminate the mass-radius relation of molecular clouds as they fragment to form globular clusters. We attribute the absence of young globular clusters in the disks of ordinary galaxies such as the Milky Way to the relatively low ambient pressures in such systems.