Sunyaev-Zel'dovich effect
Encyclopedia
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 the low energy CMB
photons receive energy boost during collision with the high energy cluster electrons. 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.
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 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. 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. The use of surveys of clusters detected by their Sunyaev–Zel'dovich 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 forthcoming surveys (SPT, ACT, Planck).
Cosmic microwave background radiation
In cosmology, cosmic microwave background radiation is thermal radiation filling the observable universe almost uniformly....
(CMB) through inverse Compton scattering, in which the low energy CMB
CMB
CMB can mean:*The IATA airport code for Bandaranaike International Airport, Colombo – Sri Lanka's only international airport*C.M.B., the debut album of American R&B and pop group Color Me Badd...
photons receive energy boost during collision with the high energy cluster electrons. 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.
Introduction
The Sunyaev–Zel'dovich effect can be divided into:- thermalThermalA thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...
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. OstrikerJeremiah P. OstrikerJeremiah Paul Ostriker is an astrophysicist at Princeton University. He received his B.A. from Harvard, his Ph.D at the University of Chicago, and then carried out post-doctoral work at the University of Cambridge. From 1971 to 1995, Ostriker was a professor at Princeton, and served as Provost...
and Ethan VishniacEthan VishniacEthan Tecumseh Vishniac is an American astrophysicist, son of Wolf V. Vishniac, and grandson of Roman Vishniac. He is the Editor-in-Chiefof the Astrophysical Journal, Director of the Center for Astrophysical Sciences and a professor of Astronomy at McMaster University in Hamilton, Canada...
.) - polarization
Rashid Sunyaev
Rashid Sunyaev
Rashid Alievich Sunyaev was born in Tashkent, Uzbek SSR, on March 1, 1943 to a Tatar family, and educated at the Moscow Institute of Physics and Technology and Moscow State University . He became a professor at MIPT in 1974...
and Yakov Zel'dovich predicted the effect, and conducted research in 1969, 1972, and 1980. The Sunyaev–Zel'dovich effect is of major astrophysical
Astrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...
and cosmological
Physical cosmology
Physical cosmology, as a branch of astronomy, is the study of the largest-scale structures and dynamics of the universe and is concerned with fundamental questions about its formation and evolution. For most of human history, it was a branch of metaphysics and religion...
interest. It can help determine the value of the Hubble constant
Hubble's law
Hubble's law is the name for the astronomical observation in physical cosmology that: all objects observed in deep space are found to have a doppler shift observable relative velocity to Earth, and to each other; and that this doppler-shift-measured velocity, of various galaxies receding from...
. To distinguish the SZ effect due to galaxy clusters from ordinary density perturbations, both the spectral
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
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 intracluster plasma in galaxy cluster
Galaxy cluster
A galaxy cluster is a compact cluster of galaxies. Basic difference between a galaxy group and a galaxy cluster is that there are many more galaxies in a cluster than in a group. Also, galaxies in a cluster are more compact and have higher velocity dispersion. One of the key features of cluster is...
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. 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. The use of surveys of clusters detected by their Sunyaev–Zel'dovich 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 forthcoming surveys (SPT, ACT, Planck).
Timeline of observations
- 1983 — Researchers from the Cambridge Radio Astronomy GroupCavendish Astrophysics GroupThe Cavendish Astrophysics Group is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank.The group is the second largest of three...
and the Owens Valley Radio ObservatoryOwens Valley Radio ObservatoryThe Owens Valley Radio Observatory is a radio observatory located near Bishop, California, within the Owens Valley, California region, approximately 250 miles north of Los Angeles on the east side of the Sierra Nevada. It is owned and operated by the California Institute of Technology. For...
first detect the Sunyaev-Zel'dovich effect from clusters of galaxiesGalaxy clusterA galaxy cluster is a compact cluster of galaxies. Basic difference between a galaxy group and a galaxy cluster is that there are many more galaxies in a cluster than in a group. Also, galaxies in a cluster are more compact and have higher velocity dispersion. One of the key features of cluster is...
. - 1993 — The Ryle TelescopeRyle TelescopeThe Ryle Telescope was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004 three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19...
is the first telescope to image a cluster of galaxiesGalaxy clusterA galaxy cluster is a compact cluster of galaxies. Basic difference between a galaxy group and a galaxy cluster is that there are many more galaxies in a cluster than in a group. Also, galaxies in a cluster are more compact and have higher velocity dispersion. One of the key features of cluster is...
in the Sunyaev–Zel'dovich effect. - 2003 — The WMAP spacecraft maps the Cosmic Microwave BackgroundCosmic microwave background radiationIn cosmology, cosmic microwave background radiation is thermal radiation filling the observable universe almost uniformly....
(CMB) over the whole sky with some (limited) sensitivity to the Sunyaev–Zel'dovich effect - 2005 — The Atacama Pathfinder Experiment - Sunyaev-Zel'dovich camera saw first light and shortly after began pointed observations of galaxy clusters.
- 2005 — The Arcminute Microkelvin ImagerArcminute Microkelvin ImagerThe Arcminute Microkelvin Imager consists of a pair of interferometric radio telescopes - the Small and Large Arrays - located at the Mullard Radio Astronomy Observatory near Cambridge. AMI was designed, built and is operated by the Cavendish Astrophysics Group...
and the Sunyaev–Zel'dovich Array each begin surveys for very high redshift clusters of galaxiesGalaxy clusterA galaxy cluster is a compact cluster of galaxies. Basic difference between a galaxy group and a galaxy cluster is that there are many more galaxies in a cluster than in a group. Also, galaxies in a cluster are more compact and have higher velocity dispersion. One of the key features of cluster is...
using the Sunyaev–Zel'dovich effect - 2007 — The South Pole TelescopeSouth Pole TelescopeThe South Pole Telescope is a 10 metre diameter telescope located at the Amundsen-Scott South Pole Station, Antarctica. It is a microwave/millimetre-wave telescope that observes in a frequency range between 70 and 300 GHz...
(SPT) saw first light on February 16, 2007, and began science observations in March of that same year. - 2007 — The Atacama Cosmology TelescopeAtacama Cosmology TelescopeThe Atacama Cosmology Telescope is a six-metre telescope on Cerro Toco in the Atacama Desert in the north of Chile, near the Llano de Chajnantor Observatory. It is designed to make high-resolution, microwave-wavelength surveys of the sky in order to study the cosmic microwave background radiation...
(ACT) saw first light on June 8, and will soon begin an SZ survey of galaxy clusters. - 2008 — The South Pole TelescopeSouth Pole TelescopeThe South Pole Telescope is a 10 metre diameter telescope located at the Amundsen-Scott South Pole Station, Antarctica. It is a microwave/millimetre-wave telescope that observes in a frequency range between 70 and 300 GHz...
(SPT) discover for the first time galaxy clusters via the SZ effect. - 2009 — The Planck spacecraft, launched on May 14, 2009, to realize a full sky SZ survey of galaxy clusters.
See also
- Background radiationBackground radiationBackground radiation is the ionizing radiation constantly present in the natural environment of the Earth, which is emitted by natural and artificial sources.-Overview:Both Natural and human-made background radiation varies by location....
- Compton effect
- Cosmic background radiation
- Cosmic microwave background radiationCosmic microwave background radiationIn cosmology, cosmic microwave background radiation is thermal radiation filling the observable universe almost uniformly....
- Rashid SunyaevRashid SunyaevRashid Alievich Sunyaev was born in Tashkent, Uzbek SSR, on March 1, 1943 to a Tatar family, and educated at the Moscow Institute of Physics and Technology and Moscow State University . He became a professor at MIPT in 1974...
- Yakov Zel'dovich
- Yoel RephaeliYoel Rephaeli407074131Yoel Rephaeli is an Israeli-American cosmologist. He is a Professor of Physics at Tel Aviv University, Israel. Rephaeli is considered an expert on the subject of the Sunyaev-Zel'dovich effect and the astrophysics of galaxy clusters.-References:...
Further reading
- Royal Astronomical Society, Corrupted echoes from the Big Bang? RAS Press Notice PN 04/01
External links
- Corrupted echoes from the Big Bang? innovations-report.com.
- Sunyaev-Zel'dovich effect on arxiv.org