Subject
- galaxy planes4
- h ii regions4
- radio sources4
- star forming regions4
- x-ray sources4
- carbon stars3
- galaxy clusters3
- millimeter astronomy3
- optical astronomy3
- protostars3
- radial velocity3
- submillimeter astronomy3
- astrophysical masers2
- black holes2
- correlation2
- h i line emission2
- infrared photometry2
- late-type stars2
- photometry2
- planetary nebulae2
