skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Two-dimensional caustics in disturbed galaxy disks

Journal Article · · Astronomical Journal; (USA)
DOI:https://doi.org/10.1086/115314· OSTI ID:6863333
 [1]
  1. Iowa State Univ. of Science and Technology, Ames (USA)

Interacting galaxies show a variety of exotic morphologies besides the well-known rings, spirals, and bars. It is proposed that many of these can be identified with nonlinear, caustic structures that are known from singularity theory to be generic in collisionless dynamics. A simple kinematical model for stellar orbits is used to study the development of caustic waveforms in galaxy disks following impulsive, nonaxially symmetric (collisional) disturbances. It appears that all of the caustics known from singularity theory to be generic in two dimensions develop as transient forms in at least some moderately off-center collisions. The more complex, higher-order caustics appear most prominently in the more off-center and larger amplitude disturbances. It is further suggested that the highly nonlinear caustic waves may play an important role in interaction-induced star formation. 38 refs.

OSTI ID:
6863333
Journal Information:
Astronomical Journal; (USA), Vol. 99; ISSN 0004-6256
Country of Publication:
United States
Language:
English