Across
- 2. is thought to be made up of a form of subatomic particle that interacts only weakly with other matter.
- 5. measured in kilometers per sec.
- 6. not flattened into disks and do not have spiral arms.
- 7. starlike objects with emission lines in their spectra.
Down
- 1. the core of an active galaxy where highly energetic objects or activities are located.
- 3. giant elliptical galaxies that emit ones as much or more energy in radio wavelengths than visible light.
- 4. gigantic formations, hundreds of millions of lightyears in size.