DYNAMICALLY INDUCED STAR FORMATION IN GALAXIES FROM THE PASSAGE OF GLOBULAR CLUSTERS

摘要

We analyze the effects a globular cluster passing through the disk of a galaxy will have on the galaxy's interstellar medium. Analysis based on the impact approximation and disk stability criteria suggests that such passage will trigger star formation in a region between 10 and 100 pc in diameter within the disk of the galaxy. Since globular clusters pass through our Galaxy every 10~6 yr, this may account for a small but still significant amount of the star formation in our Galaxy. In galaxies with weak spiral density waves and abundant subcritical H I gas, the interaction of globular clusters with the interstellar medium may play an important role in forming stars. The discovery of H I bubbles in the interstellar medium of other galaxies might be caused by a globular cluster triggering a wave of self-propagating star formation in their disks.