Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso


  • William M. Irvine
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1549-3



Motion with velocities much larger than the characteristic local thermal (Maxwellian) velocity is called suprathermal or superthermal. Processes involving magnetic fields, such as solar flares, can produce suprathermal particle motions. In the case of interstellar dust grains, suprathermal rotation has been invoked as a process involved in the grain alignment that is responsible for polarizing transmitted radiation.

Although the term suprathermal could also in principle be applied to situations like astrophysical masers, where a group of atoms or molecules exists in a condition with more members in an excited energy state than in a linked lower energy state (thus providing a negative thermodynamic temperature and the possibility of stimulated emission of radiation), this use of the term has not been in common use.

See Also


Magnetic Field Lower Energy Energy State Bioorganic Chemistry Particle Motion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References and Further Reading

  1. Whittet DCB (2003) Dust in the galactic environment, vol 2. Institute of Physics Publishing, BristolGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Department of AstronomyUniversity of MassachusettsAmherstUSA