The nearly edge-on S0 galaxy NGC 5866 is notable for its massive molecular interstellar medium, prominent central dust lane, and large IRAS 100 micron flux. The galaxy is relatively isolated, and neither the kinematics nor morphology of the gas suggests that a merger has taken place. Instead, NGC 5866 may be entering an era of star formation fueled with gas donated by its aging stellar population. Are we seeing a counter example of the popular view that galaxies evolve through mergers? We explore that possibility using multi-transition CO observations and SCUBA (Submillimetre Common-User Bolometer Array) imagery of NGC 5866. We analyze the dust and gas components of the interstellar medium using techniques such as the large velocity gradient (LVG) models and a three-dimensional Monte Carlo radiation transfer code. A comparison of SCUBA and appropriately convolved H alpha images reveals both to have similar structure and morphology. This complements the fact that the SCUBA fluxes were under predicted by the Monte Carlo code which does not take star formation into account. Both of those facts indicate that NGC 5866 is indeed under going star formation. This is consistent with spiral-type star formation rates predicted by our LVG modeling.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2003