Interstellar medium
Interstellar medium is the matter that exists in the space between stars within a galaxy. It consists primarily of gas, dust, and cosmic rays and plays a role in star formation and galactic dynamics.
The interstellar medium is discussed in astrophysics, galactic astronomy, and plasma physics.
Status
The interstellar medium is studied through observations across multiple wavelengths, including radio, infrared, optical, and X-ray. Models of its composition, structure, and interaction with stars and magnetic fields continue to be developed.