- Introduction
- Face-on map overview
- Sources
- The Cloud Hunters
- The Star Sweepers
- Things Unseen: The Westerhout radio sources
- The Avedisova catalog: A real Hitchhiker's Guide to the Galaxy?
- Avedisova glossary
- Introduction to the Milky Way Explorer
- Commentary on the Galactic Plane
- Hydrogen-alpha commentary
- Fragments
Caswell/Haynes HII regions
This is a cross reference listing the Caswell/Haynes HII regions contained in the Avedisova catalog. The official SIMBAD designation for each object is linked to its SIMBAD entry. The Avedisova region is linked to the Avedisova detail page for that region. The table also includes the Avedisova subregion, size of the object in arcminutes, the electron temperature, three distance columns and notes from the original catalog.
The objects are listed more than once if they occur in multiple Avedisova subregions.
The three distance columns show the near distance estimate, the far distance estimate (if any), and often a flag set to N or F showing which distance estimate is more likely. The distance estimates are in kpc and are derived using a distance to the galactic centre of 10 kpc. Most other estimates on this site are derived using a distance to the galactic centre of 8.5 kpc. As the Caswell/Haynes paper explains, in the vast majority of cases (all objects within the solar circle), you can simply multiply these estimates by 0.85 to convert to a shorter distance to the galactic centre.