Astrophysical plasma

Observational evidence

Astrophysical plasma may be studied in a variety of ways since they emit X-ray observatories, performed in the upper atmosphere or space, such as by the Chandra X-ray Observatory satellite. Astrophysical plasmas also emit radio waves and gamma rays.

Space plasma characteristics

Space plasma pioneers Hannes Alfvén and Carl-Gunne Fälthammar divided the plasmas in the solar system into three different categories:

Research and investigation

Both instabilities. Although these phenomena can occur on scales as large as the galactic core, most physicists believe that most phenomena on the largest scales do not involve plasma effects.

In physical cosmology

In the big bang cosmology the entire universe was a plasma prior to recombination. Afterwards, much of the universe reionized after the first quasars formed and emitted radiation which reionized most of the universe, which largely remains in plasma form. It is believed by many scientists that very little baryonic matter is neutral. In particular, the solar winds are all mainly diffuse plasmas, and stars are made of dense plasma. The study of astrophysical plasmas is part of the mainstream of academic astrophysics and is taken in account for in the standard cosmological model; however, current models indicate that plasma processes have little role to play in forming the very largest structures, such as voids, galaxy clusters and superclusters.

History

In 1913, Norwegian explorer and physicist Kristian Birkeland may have been the first to predict that space is filled with ions of all kinds. We have assumed that each stellar system in evolutions throws off electric corpuscles into space. It does not seem unreasonable therefore to think that the greater part of the material masses in the universe is found, not in the solar systems or nebulae, but in "empty" space. ^[1]

In 1937, plasma physicist Hannes Alfvén argued that if plasma pervaded the universe, then it could generate a galactic magnetic field. During the 1940s and 50s, Alfvén developed magnetohydrodynamics (MHD) which enables plasmas to be modelled as waves in a fluid, for which Alfvén won the 1970 Nobel Prize for physics. MHD is a standard astronomical tool.