page_title: Sunyaev–Zeldovich effect
section_title: Observations
hierarchical_section_title: Sunyaev–Zeldovich effect / Observations
caption_attribution_description: English: The events surrounding the Big Bang were so cataclysmic that they left an indelible imprint on the fabric of the cosmos. We can detect these scars today by observing the oldest light in the Universe. As it was created nearly 14 billion years ago, this light — which exists now as weak microwave radiation and is thus named the cosmic microwave background (CMB) — has now expanded to permeate the entire cosmos, filling it with detectable photons. The CMB can be used to probe the cosmos via something known as the Sunyaev-Zel’dovich (SZ) effect, which was first observed over 30 years ago. We detect the CMB here on Earth when its constituent microwave photons travel to us through space. On their journey to us, they can pass through galaxy clusters that contain high-energy electrons. These electrons give the photons a tiny boost of energy. Detecting these boosted photons through our telescopes is challenging but important — they can help astronomers to understand some of the fundamental properties of the Universe, such as the location and distribution of dense galaxy clusters. This image shows the first measurements of the thermal Sunyaev-Zel’dovich effect from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile (in blue). Astronomers combined data from ALMA’s 7- and 12-metre antennas to produce the sharpest possible image. The target was one of the most massive known galaxy clusters, RX J1347.5–1145, the centre of which shows up here in the dark “hole” in the ALMA observations. The energy distribution of the CMB photons shifts and appears as a temperature decrease at the wavelength observed by ALMA, hence a dark patch is observed in this image at the location of the cluster. Links ESA/Hubble Picture of the Week
context_page_description: The Sunyaev–Zeldovich effect is the distortion of the cosmic microwave background radiation through inverse Compton scattering by high-energy electrons in galaxy clusters, in which the low-energy CMB photons receive an average energy boost during collision with the high-energy cluster electrons. Observed distortions of the cosmic microwave background spectrum are used to detect the disturbance of density in the universe. Using the Sunyaev–Zeldovich effect, dense clusters of galaxies have been observed.
context_section_description: In 1984, researchers from the Cambridge Radio Astronomy Group and the Owens Valley Radio Observatory first detected the Sunyaev–Zeldovich effect from clusters of galaxies . Ten years later, the Ryle Telescope was used to image a cluster of galaxies in the Sunyaev–Zeldovich effect for the first time.
  Instruments built specifically to study the effect include the Sunyaev–Zeldovich camera on the Atacama Pathfinder Experiment, and the Sunyaev–Zeldovich Array, which both saw first light in 2005. In 2012, the Atacama Cosmology Telescope (ACT) performed the first statistical detection of the kinematic SZ effect. In 2012 the kinematic SZ effect was detected in an individual object for the first time in MACS J0717.5+3745.
caption: First measurements of the thermal Sunyaev–Zeldovich effect from the Atacama Large Millimeter Array with one of the most massive galaxy clusters known, RX J1347.5-1145.[3]
exif: {"Image ImageDescription": "The events surrounding the Big Bang were so cataclysmic that they left an indelible imprint on the fabric of the cosmos. We can detect these scars today by observing the oldest light in the Universe. As it was created nearly 14 billion years ago, this light \u2014 which exists now as weak microwave radiation and is thus named the cosmic microwave background (CMB) \u2014 has now expanded to permeate the entire cosmos, filling it with detectable photons. The CMB can be used to probe the cosmos via something known as the Sunyaev-Zel\u2019dovich (SZ) effect, which was first observed over 30 years ago. We detect the CMB here on Earth when its constituent microwave photons travel to us through space. On their journey to us, they can pass through galaxy clusters that contain high-energy electrons. These electrons give the photons a tiny boost of energy. Detecting these boosted photons through our telescopes is challenging but important \u2014 they can help astronomers to understand some of the fundamental properties of the Universe, such as the location and distribution of dense galaxy clusters. This image shows the first measurements of the thermal Sunyaev-Zel\u2019dovich effect from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile (in blue). Astronomers combined data from ALMA\u2019s 7- and 12-metre antennas to produce the sharpest possible image. The target was one of the most massive known galaxy clusters, RX J1347.5\u20131145, the centre of which shows up here in the dark \u201chole\u201d in the ALMA observations. The energy distribution of the CMB photons shifts and appears as a temperature decrease at the wavelength observed by ALMA, hence a dark patch is observed in this image at the location of the cluster. Links  ESA/Hubble Picture of the Week", "Image Software": "Adobe Photoshop CC 2017 (Windows)", "Image DateTime": "2017:02:14 10:00:57"}