Editing Sunyaev–Zeldovich effect (section)

== Overview ==
The Sunyaev–Zeldovich effect was predicted by [[Rashid Sunyaev]] and [[Yakov Zeldovich]] to describe anisotropies in the CMB. The effect is caused by the CMB interacting with high energy electrons. These high energy electrons cause inverse Compton scattering of CMB photons which causes a distortion in the radiation spectrum of the CMB. The Sunyaev–Zeldovich effect is most apparent when observing galactic clusters. Analysis of CMB data at higher angular resolution (high [[Multipole|<math>\ell</math>-values]]) requires taking into account the Sunyaev–Zeldovich effect.

The Sunyaev–Zeldovich effect can be divided into different types:

* [[Thermal energy|Thermal]] effects, where the CMB photons interact with electrons that have high energies due to their temperature
* [[Kinematic]] effects, a second-order effect where the CMB photons interact with electrons that have high energies due to their bulk motion (also called the Ostriker–Vishniac effect, after [[Jeremiah P. Ostriker]] and [[Ethan Vishniac]].<ref>{{Cite journal|last1=Ostriker|first1=Jeremiah P.|last2=Vishniac|first2=Ethan T.|name-list-style=amp|date=1986|title=Generation of Microwave Background Fluctuations from Nonlinear Perturbations at the Era of Galaxy Formation|journal=Astrophysical Journal Letters|volume=306|page=L51|bibcode=1986ApJ...306L..51O|doi=10.1086/184704}}</ref>)
* [[Polarization (waves)|Polarization]]

The Sunyaev–Zeldovich effect is of major [[Astrophysics|astrophysical]] and [[Physical cosmology|cosmological]] interest. It can help determine the value of the [[Hubble's law|Hubble constant]], determine the location of new galaxy clusters, and in the study of cluster structure and mass. Since the Sunyaev–Zeldovich effect is a scattering effect, its magnitude is independent of redshift, which means that clusters at high redshift can be detected just as easily as those at low redshift.