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[[File:NGC 4402 Hubble heic0911c.jpg|thumb|300px|right|Ram pressure stripping in [[NGC 4402]] as it falls towards the [[Virgo Supercluster]] (off image, bottom left). Note the [[cosmic dust|dust]] (brown) trailing behind the galaxy.]] | |||
In [[physics]], '''ram pressure''' is a [[pressure]] exerted on a body which is moving through a [[fluid]] medium. It causes a strong [[drag (physics)| drag]] force to be exerted on the body. It is given by: | |||
<math>P= \rho v^2</math> <ref> Relativistic Astrophysics and Cosmology, A Fabian and Lasenby, University of Cambridge Lecture Notes, Michaelmas 2010. </ref> | |||
where P is the pressure, <math>\rho</math> is the density of the fluid and v the velocity of the body. Alternatively the body can be stationary and v describe the velocity of the fluid, e.g. the [[solar wind]]. | |||
For example, a [[meteor]] traveling through the Earth's atmosphere produces a [[shock wave]] generated by the extremely rapid compression of air in front of the meteoroid. It is primarily this ram pressure (rather than [[friction]]) which heats the air which in turn heats the meteoroid as it flows around it.<ref>Plait, p.1</ref> | |||
[[Galaxy|Galaxies]] in [[galaxy cluster|clusters]] experience ram pressure as they move through the [[intracluster medium]]; it is capable of stripping the galaxy of much of its [[interstellar gas]].<ref> Grebel, Gallagher, Harbeck, pp.1-15</ref> | |||
==Notes== | |||
<div class="references-small"><references/></div> | |||
==References== | |||
*Grebel, Gallagher, Harbeck (2003) [http://arxiv.org/abs/astro-ph/0301025 ''The Progenitors of Dwarf Spheroidal Galaxies'' ] ArXiv.org. retrieved Nov. 2007 | |||
== External links == | |||
*[http://arxiv.org/abs/physics/0609156 Educational materials on air resistance] | |||
{{astronomy-stub}} | |||
[[Category:Fluid dynamics]] | |||
Revision as of 09:39, 23 June 2013
In physics, ram pressure is a pressure exerted on a body which is moving through a fluid medium. It causes a strong drag force to be exerted on the body. It is given by:
where P is the pressure, is the density of the fluid and v the velocity of the body. Alternatively the body can be stationary and v describe the velocity of the fluid, e.g. the solar wind.
For example, a meteor traveling through the Earth's atmosphere produces a shock wave generated by the extremely rapid compression of air in front of the meteoroid. It is primarily this ram pressure (rather than friction) which heats the air which in turn heats the meteoroid as it flows around it.[2]
Galaxies in clusters experience ram pressure as they move through the intracluster medium; it is capable of stripping the galaxy of much of its interstellar gas.[3]
Notes
References
- Grebel, Gallagher, Harbeck (2003) The Progenitors of Dwarf Spheroidal Galaxies ArXiv.org. retrieved Nov. 2007
External links
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