A new method for studying the spiral structure of galaxies, with M33 taken as an example
Abstract
The paper proposes a method for the investigation of the spiral structure of galaxies which is based on the correlation of the locations of a number of subgroups spatially distributed within the star-formation zones: subgroups of extremally young O stars and H II regions, and subgroups of older B stars without ionized gas. The small difference in the age of these subgroups (less than 10-million years) and the minimum velocity dispersion make possible a clear delineation of the spiral structure and assure that the spiral-structure parameters are determined with a relatively high accuracy. The objects of each subgroup form a spiral pattern, and spiral branches formed by objects of various ages must intersect at the point of corotation. As an example, this method is applied to M33.
- Publication:
-
Akademiia Nauk Tadzhikskoi SSR Doklady
- Pub Date:
- 1981
- Bibcode:
- 1981DoTad..24..725S
- Keywords:
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- Galactic Rotation;
- Galactic Structure;
- Spiral Galaxies;
- Stellar Evolution;
- B Stars;
- H Ii Regions;
- Ionized Gases;
- O Stars;
- Spatial Distribution;
- Astrophysics