It would also be reasonable to assume that gas clouds are present as well. Globular clusters can be thought of as small cousins to elliptical galaxies . They are spherical conglomerations of stars held together by their mutual force of gravity. No star formation is taking place within them. The globular clusters orbit the nucleus of their parent galaxies and define a spherical region thought to demark the confines of the galactic halo.
Globular clusters contain stars which are very old.
Most are thought to have formed about 10,000 million years ago. The largest globular clusters contain a few million stars. Spiral galaxies will, typically, have around 150 globular clusters, whilst elliptical galaxies can have up to one thousand. It is thought that when gas clouds collapsed to form galaxies, isolated regions collapsed separately and formed globular clusters. Beyond the galactic halo many astronomers believe that an even larger spherical region, known as the corona, exists.