Astrophysical plasma
File:VST images the Lagoon Nebula.jpg is a large, low-density cloud of partially ionized gas.{{cite news|title=Sneak Preview of Survey Telescope Treasure Trove|url=http://www.eso.org/public/news/eso1403/|access-date=23 January 2014|newspaper=ESO Press Release}} ]]
Astrophysical plasma is plasma outside of the Solar System. It is studied as part of astrophysics and is commonly observed in space.{{Cite web
|url=https://news.mit.edu/2017/study-uncovers-new-mechanisms-astrophysical-plasma-turbulence-1201
|title=Study sheds light on turbulence in astrophysical plasmas: Theoretical analysis uncovers new mechanisms in plasma turbulence
|date=December 2017
|publisher=MIT News
|access-date=2018-02-20}} The accepted view of scientists is that much of the baryonic matter in the universe exists in this state.{{Cite book
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|chapter=Particle Orbit Theory
|series=UNITEXT for Physics
|date=2015
|title=Basics of Plasma Astrophysics
|page=17
|doi=10.1007/978-88-470-5280-2_2
|isbn=978-88-470-5280-2|bibcode=2015bps..book.....C
}}
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.{{GoldBookRef|title=Ionization|file=I03183}} 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.{{Cite journal|author1-link=Alexandre Lazarian
|title=Understanding of the role of magnetic fields: Galactic perspective
|journal=Astro2010: The Astronomy and Astrophysics Decadal Survey
|volume=2010
|pages=175
|author1=Lazarian, A.|author2=Boldyrev, S.|author3=Forest, C.|author4=Sarff, P.
|bibcode=2009astro2010S.175L
|year=2009
|arxiv=0902.3618
}} Similarly, electric fields are observed in some stellar astrophysical phenomena, but they are inconsequential in very low-density gaseous media.
Astrophysical plasma is often differentiated from space plasma, which typically refers to the plasma of the Sun, the solar wind, and the ionospheres and magnetospheres of the Earth and other planets.{{cite web|url=http://www.oulu.fi/~spaceweb/textbook/
|title=Space Physics Textbook |date=2006-11-26
|access-date=2018-02-23
|archive-url=https://web.archive.org/web/20081218061302/http://www.oulu.fi/~spaceweb/textbook/
|archive-date=December 18, 2008 }}{{Cite web
|url=http://sp2rc.group.shef.ac.uk/
|title=The Solar Physics and Space Plasma Research Centre (SP2RC)
|publisher=MIT News
|access-date=2018-02-23}}{{Cite journal
|last1=Owens|first1=Mathew J.
|last2=Forsyth|first2=Robert J.
|title=The Heliospheric Magnetic Field
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|issue=1
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|doi=10.12942/lrsp-2013-5
|doi-access=free
|issn=2367-3648
|bibcode = 2013LRSP...10....5O |arxiv=1002.2934
|s2cid=122870891
|first=Andrew F.|last= Nagy
|pages=1–2
|title=Comparative Aeronomy
|author2=Balogh, André
|author3= Thomas E. Cravens
|author4=Mendillo, Michael
|author5=Mueller-Woodarg, Ingo
|publisher=Springer
|year=2008
|isbn=978-0-387-87824-9}}{{cite book
|last=Ratcliffe|first=John Ashworth
|title=An Introduction to the Ionosphere and Magnetosphere
|year=1972
|publisher=CUP Archive
|isbn=978-0-521-08341-6
|url=https://archive.org/details/introductiontoio0000ratc|url-access=registration}}NASA Study Using Cluster Reveals New Insights Into Solar Wind, NASA, Greenbelt, 2012, p.1{{cite journal
|last = Cade III
|first = William B.
|author2 = Christina Chan-Park
|title = The Origin of "Space Weather"
|journal=Space Weather
|volume = 13|issue = 2|pages =99
|date=2015
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|bibcode = 2015SpWea..13...99C|doi-access = free
}}
Observing and studying astrophysical plasma
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. In particular, the intergalactic medium, the interstellar medium, the interplanetary medium and solar winds consist of diffuse plasmas.
Early history
Norwegian explorer and physicist Kristian Birkeland predicted that space is filled with plasma. He wrote in 1913: {{quote|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.{{cite book |last=Birkeland|first=Kristian
|title=The Norwegian Aurora Polaris Expedition 1902–1903
|year=1908
|page=[https://archive.org/details/norwegianaurorap01chririch/page/720 720]
|publisher=H. Aschehoug & Co
|location=New York and Christiania (now Oslo)
|url=https://archive.org/details/norwegianaurorap01chririch}} out-of-print, full text online.
References
{{Reflist}}
External links
- "[https://web.archive.org/web/20050905223019/http://astrosun.tn.cornell.edu/us-rus/ US / Russia Collaboration in Plasma Astrophysics]"
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