Interstellar medium

Frae Wikipedia, the free beuk o knawledge
The distribution o ionised hydrogen (kent bi astronomers as H II frae auld spectroscopic terminology) in the pairts o the Galactic interstellar medium visible frae the Yird's northren hemisphere as observed wi the Wisconsin Hα Mapper (Haffner et al. 2003).

In astronomy, the interstellar medium (ISM) is the matter that exeests in the space atween the starn seestems in a galaxy. This matter includes gas in ionic, atomic, an molecular form, as well as dust an cosmic rays. It fills interstellar space an blends smuithly intae the surroondin intergalactic space. The energy that occupies the same volume, in the form o electromagnetic radiation, is the interstellar radiation field.