Astrophysical plasma is
plasma outside of the
Solar System. It is studied as part of
astrophysics and is commonly observed in space.[2] The accepted view of scientists is that much of the
baryonic matter in the
universe exists in this state.[3]
When matter becomes sufficiently hot and energetic, it becomes
ionized and forms a plasma. This process breaks matter into its constituent particles which includes negatively charged
electrons and positively charged
ions.[4] These electrically charged particles are susceptible to influences by local
electromagnetic fields. This includes
strong fields generated by
stars, and weak fields which exist in
star forming regions, in
interstellar space, and in
intergalactic space.[5] Similarly,
electric fields are observed in some stellar astrophysical phenomena, but they are inconsequential in very low-density gaseous media.
Plasmas in stars can both generate and interact with
magnetic fields, resulting in a variety of dynamic astrophysical phenomena. These phenomena are sometimes observed in spectra due to the
Zeeman effect. Other forms of astrophysical plasmas can be influenced by preexisting weak magnetic fields, whose interactions may only be determined directly by
polarimetry or other indirect methods.[5] In particular, the
intergalactic medium, the
interstellar medium, the
interplanetary medium and
solar winds consist of diffuse plasmas.
Possible related phenomena
Scientists are interested in
active galactic nuclei because such astrophysical plasmas could be directly related to the plasmas studied in laboratories.[13] Many of these phenomena seemingly exhibit an array of complex
magnetohydrodynamic behaviors, such as
turbulence and
instabilities.[2]
Norwegian explorer and physicist
Kristian Birkeland predicted that space is filled with
plasma. He wrote in 1913:
It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric
ions of all kinds. We have assumed that each
stellar system through its evolution throws off electric corpuscles into space.
Birkeland assumed that most of the mass in the universe should be found in "empty" space.[15]
^
abLazarian, A.; Boldyrev, S.; Forest, C.; Sarff, P. (2009). "Understanding of the role of magnetic fields: Galactic perspective". Astro2010: The Astronomy and Astrophysics Decadal Survey. 2010: 175.
arXiv:0902.3618.
Bibcode:
2009astro2010S.175L.
^Nagy, Andrew F.; Balogh, André; Thomas E. Cravens; Mendillo, Michael; Mueller-Woodarg, Ingo (2008). Comparative Aeronomy. Springer. pp. 1–2.
ISBN978-0-387-87824-9.