Spiral galaxies consist of a flattened rotating disk of young stars, a
central bulge of generally older stars, and a surrounding halo of
older stars and dense clusters of old stars called globular
clusters. The disk is prominent due to the presence of young, hot
stars often arranged in a spiral pattern.
Spiral galaxies are sometimes the hosts of energetic
nuclei which emit jets of high-energy particles which are
visible in the radio. Images of those objects are categorized
separately under the heading , most often in the
Click any thumbnail below to view the details of
that image. Other images of the atomic hydrogen in spiral galaxies
can be found in the . Visit non-NRAO
website for more information on spiral galaxies.