Sunyaev-Zel'dovich effect

From Wikipedia, the free encyclopedia

Physical cosmology

Universe · Big Bang Age of the universe Timeline of the Big Bang Ultimate fate of the universe Early Universe Inflation · Nucleosynthesis GWB · Neutrino Background Cosmic microwave background Expanding universe Redshift · Hubble's law Metric expansion of space Friedmann equations FLRW metric Structure formation Shape of the universe Structure formation Galaxy formation Large-scale structure Components Lambda-CDM model Dark energy · Dark matter Timeline Timeline of cosmology... Experiments Observational cosmology 2dF · SDSS COBE · BOOMERanG · WMAP Scientists Einstein · Hawking · Friedman · Lemaître · Hubble · Penzias · Wilson · Gamow · Dicke · Zel'dovich · Mather · Rubin · Smoot· others

This box: view • talk • edit

The Sunyaev-Zel'dovich effect (often abbreviated as the SZ effect) is the result of high energy electrons distorting the cosmic microwave background radiation (CMB) through inverse Compton scattering, in which some of the energy of the electrons is transferred to the low energy CMB photons. Observed distortions of the cosmic microwave background spectrum are used to detect the density perturbations of the universe. Using the Sunyaev-Zel'dovich effect, dense clusters of galaxies have been observed.

Contents 1 Introduction 2 Timeline of observations 3 See also 4 References 4.1 Journals 5 Further reading 6 External links

[edit] Introduction

The Sunyaev-Zel'dovich effect can be divided into:

• 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.^[1])
• polarization

Rashid Sunyaev and Yakov Zel'dovich predicted the effect, and conducted research in 1969, 1972, and 1980. The Sunyaev-Zel'dovich effect is of major astrophysical and cosmological interest. It can help determine the value of the Hubble constant. To distinguish the SZ effect due to galaxy clusters from ordinary density perturbations, both the spectral dependence and the spatial dependence of fluctuations in the cosmic microwave background are used. Analysis of CMB data at higher angular resolution (high l values) requires taking into account the Sunyaev-Zel'dovich effect.

Current research is focused on modelling how the effect is generated by the intra-cluster plasma in galaxy clusters, 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. Observations are difficult due to the small amplitude of the effect and to confusion with experimental error and other sources of CMB temperature fluctuations. However, since the Sunyaev-Zel'dovich effect is a scattering effect, its magnitude is independent of redshift. This is very important: it means that clusters at high redshift can be detected just as easily as those at low redshift. Another factor which facilitates high-redshift cluster detection is the 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.

[edit] Timeline of observations

• 1983 — Researchers from the Cambridge Radio Astronomy Group and the Owens Valley Radio Observatory first detect the Sunyaev-Zel'dovich effect from clusters of galaxies.
• 1993 — The Ryle Telescope begins regular observations of the Sunyaev-Zel'dovich effect from clusters of galaxies
• 2003 — The WMAP satellite maps the Cosmic Microwave Background (CMB) over the whole sky with some (limited) sensitivity to the Sunyaev-Zel'dovich effect
• 2005 — The Arcminute Microkelvin Imager and the Sunyaev-Zel'dovich Array each begin surveys for very high redshift clusters of galaxies using the Sunyaev-Zel'dovich effect
• 2007 — The South Pole Telescope (SPT) saw first light on February 16, 2007, and began science observations in March of that same year.
• 2007 — The Atacama Cosmology Telescope (ACT) saw first light on June 8, and will soon begin an SZ survey of galaxy clusters

[edit] See also

• Background radiation
• Compton effect
• Cosmic background radiation
• Cosmic microwave background radiation
• Rashid Sunyaev
• Yakov Zel'dovich
• Yoel Rephaeli

[edit] References

[edit] Journals

• Birkinshaw; et al. (1984). "The Sunyaev-Zel'dovich effect towards three clusters of galaxies". Nature 309: 34–35. doi:10.1038/309034a0. 
• Birkinshaw, Mark (1999). "The Sunyaev Zel'dovich Effect". Physics Reports 310: 97. 
• Cen, Renyue; Jeremiah P. Ostriker (1994). "A hydrodynamic approach to cosmology: the mixed dark matter cosmological scenario". The Astrophysical Journal 431: 1. 
• Hu, Jian; Yu-Qing Lou. "Magnetic Sunyaev-Zel'dovich effect in galaxy clusters". ApJL. arXiv:astro-ph/0402669. 
• Ma, Chung-Pei; J. N. Fry (May 27, 2002). "Nonlinear Kinetic Sunyaev-Zel'dovich Effect". PRL. arXiv:astro-ph/0106342. 
• Myers, A. D.; et al.. "Evidence for an Extended SZ Effect in WMAP Data". Astrophysics. arXiv:astro-ph/0306180. 
• Rephaeli, Y. (1995). "Comptonization Of The Cosmic Microwave Background: The Sunyaev-Zeldovich Effect". Annual Review of Astronomy and Astrophysics 33: 541–580. 
• Springel, Volker; Martin White and Lars Hernquist. "Hydrodynamic Simulations of the Sunyaev-Zel'dovich effect(s)". ApJ. arXiv:astro-ph/0008133. 
• Sunyaev, R. A.; Ya. B. Zel'dovich (1970). "Small-Scale Fluctuations of Relic Radiation". Astrophysics and Space Science 7: 3. 
• Sunyaev, R. A.; Ia. B Zel'dovich (1980). "Microwave background radiation as a probe of the contemporary structure and history of the universe". Annual review of astronomy and astrophysics 18: 537–560. 
• Diego, J.M; E. Martinez, J.L. Sanz, N. Benitez, J. Silk (2002). "The Sunyaev-Zel'dovich effect as a cosmological discriminator". Monthly Notices of the Royal Astronomical Society, 331: 556–568. 

[edit] Further reading

• Royal Astronomical Society, Corrupted echoes from the Big Bang? RAS Press Notice PN 04/01

[edit] External links

• Corrupted echoes from the Big Bang? innovations-report.com.