The interstellar medium (ISM) refers to the matter and radiation that exists in the space between stars in a galaxy. It is composed of gas (mostly hydrogen and helium), dust, and cosmic rays.
Studying the interstellar medium is important because it provides crucial information about the physical conditions and processes that occur in the space between stars. It also plays a key role in the formation and evolution of stars and galaxies.
Radiative processes refer to the emission, absorption, and scattering of electromagnetic radiation in astrophysical systems. This includes various forms of light such as radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Some popular introductory books on this topic include "Interstellar Medium: Physics and Chemistry in Space" by A. G. G. M. Tielens, "The Physics of the Interstellar and Intergalactic Medium" by Bruce T. Draine, and "Radiative Processes in Astrophysics" by George B. Rybicki and Alan P. Lightman.
Yes, there are several advanced books that delve deeper into the topic, such as "Interstellar Dust: Properties, Evolution, and Impact" by B.T. Draine, "Astrophysics of the Interstellar Medium" by Walter J. Maciel, and "Radiative Transfer in Stellar Atmospheres" by Dimitri Mihalas.