Editing Sunyaev–Zeldovich effect (section)

== Research ==
Current research is focused on modelling how the effect is generated by the intracluster plasma in [[galaxy cluster]]s, and on using the effect to estimate the [[Hubble constant]] and to separate different components in the angular average statistics of fluctuations in the background. Hydrodynamic structure formation simulations are being studied to gain data on thermal and kinetic effects in the theory.<ref>{{Cite journal|last1=Cunnama D.|first1=Faltenbacher F.|last2=Passmoor S.|first2=Cress C.|last3=Cress|first3=C.|last4=Passmoor|first4=S.|date=2009|title=The velocity-shape alignment of clusters and the kinetic Sunyaev–Zeldovich effect|journal=MNRAS Letters|volume=397|issue=1|page=L41–L45|arxiv=0904.4765|bibcode=2009MNRAS.397L..41C|doi=10.1111/j.1745-3933.2009.00680.x|doi-access=free |s2cid=9809159}}</ref> Observations are difficult due to the small amplitude of the effect and to confusion with experimental error and other sources of CMB temperature fluctuations. To distinguish the SZ effect due to galaxy clusters from ordinary density perturbations, both the [[Electromagnetic spectrum|spectral]] dependence and the spatial dependence of fluctuations in the [[cosmic microwave background]] are used.

A factor which facilitates high redshift cluster detection is the [[Angular size redshift relation|angular scale versus redshift relation]]: it changes little between redshifts of 0.3 and 2, meaning that clusters between these redshifts have similar sizes on the sky. The use of surveys of clusters detected by their Sunyaev–Zeldovich effect for the determination of cosmological parameters has been demonstrated by Barbosa et al. (1996). This might help in understanding the dynamics of dark energy in surveys ([[South Pole Telescope]], [[Atacama Cosmology Telescope]], ''[[Planck (spacecraft)|Planck]]'').