Density Wave Kinematics and Giant Molecular Association Formation in M51
Abstract
The small-scale kinematics of the molecular, atomic, and ionized gas components along the major and minor axes of M51, derived from optical emission-line spectroscopy and CO and HI interferometric observations, are compared with the predictions of current models of the gaseous response to a density wave. Determinations of the gas surface density and observations of the kinematics are used to test quantitatively the two suggested mechanisms of arm and interarm giant molecular association (GMA) formation. The possible connection between GMA formation and the triggering of star formation is briefly discussed. Attention is also given to the difficulties associated with the existence of bound arm GMAs, and it is shown how these could be alleviated if the GMAs were not bound.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1993
- DOI:
- 10.1086/172725
- Bibcode:
- 1993ApJ...410...68R
- Keywords:
-
- Density Distribution;
- Galactic Structure;
- Interstellar Gas;
- Molecular Clouds;
- Spiral Galaxies;
- Astronomical Spectroscopy;
- Galactic Nuclei;
- Galactic Rotation;
- Star Formation;
- Very Large Array (Vla);
- Astrophysics;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M51;
- GALAXIES: KINEMATICS AND DYNAMICS;
- ISM: MOLECULES;
- RADIO LINES: ISM