Corrugations in the Disk of the Edge-On Spiral Galaxy IC 2233
Abstract
We recently reported the discovery of a regular corrugation pattern in the H I disk of the isolated, edge-on spiral galaxy IC 2233. Here we present measurements of the vertical structure of this galaxy at several additional wavelengths, ranging from the far-ultraviolet to the far-infrared. We find that undular patterns with amplitude lesssim5'' (lesssim 250 pc) are visible in a variety of Population I tracers in IC 2233, including the young to intermediate-age stars, the H II regions, and the dust. However, the vertical excursions become less pronounced in the older stellar populations traced by the mid-infrared light. This suggests that the process leading to the vertical displacements may be linked with the regulation of star formation in the galaxy. We have also identified a relationship between the locations of the density corrugations and small-amplitude (lesssim 5 km s-1) velocity undulations in the H I rotation curve. We are able to exclude several possible mechanisms for the origin of the observed corrugations, including tidal interaction from a companion, Parker instabilities, or a galactic bore. Global gravitational instabilities appear to be the most likely explanation, although local perturbations may also be important.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2008
- DOI:
- 10.1086/592086
- arXiv:
- arXiv:0807.3560
- Bibcode:
- 2008ApJ...688..237M
- Keywords:
-
- galaxies: individual: IC 2233;
- galaxies: spiral;
- galaxies: structure;
- instabilities;
- ISM: structure;
- Astrophysics
- E-Print:
- accepted to ApJ