Any of the short answer questions in the web notes pages, or the Review questions at the end of the chapters are typical. Sample Multiple Choice Questions 1. Radio maps of the Milky Way reveals that the Galaxy has at least four separate spiral arms two spiral arms no spiral arms too much dust to detect spiral arms 2. Spiral arms require new stars and star formation has ended Galaxies are not rotating fast enough to create spiral arms There are no known mechanisms to produce spiral arms Differential rotation should wind up the arms until they disappear 5. Sa SBc E0 E7 6.
Active galaxies produce significant emission at their centers.
Irregular Spiral Elliptical Dwarf 11. Bottom-up galaxy formation is a theory which postulates that great sheets of matter condensed that then broke up into individual galaxies. In the early 60's quasars were discovered to have strange emission lines. The explanation for these lines is that quasars contain elements unknown on Earth.