Max Planck Institute for Astrophysics | ALMA | 2017 Mar 17
Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) successfully imaged a radio “hole” around a galaxy cluster 4.8 billion light-years away. This is the highest resolution image ever taken of such a hole caused by the Sunyaev-Zel'dovich effect (SZ effect). The image proves ALMA’s high capability to investigate the distribution and temperature of gas around galaxy clusters through the SZ effect.
- The image shows the measurement of the SZ effect in the galaxy cluster RX J1347.5-1145 taken with ALMA (blue). The background image was taken by the Hubble Space Telescope. A “hole” caused by the SZ effect is seen in the ALMA observations.
Credit: ESA/Hubble & NASA, ALMA (ESO/NAOJ/NRAO),
T. Kitayama (Toho University, Japan)
A research team led by Tetsu Kitayama, Toho University, Japan, and Eiichiro Komatsu, Max Planck Institute for Astrophysics, Germany, used ALMA to investigate the hot gas in a galaxy cluster. The hot gas is a key component to understand the nature and evolution of galaxy clusters. Even though the hot gas does not emit radio waves itself, which would be detectable with ALMA, the gas scatters the radio waves of the Cosmic Microwave Background and makes a “hole” around the galaxy cluster. This is called the Sunyaev-Zel'dovich effect.
The team observed the galaxy cluster RX J1347.5-1145 located 4.8 billion light-years away. This galaxy cluster is well known among astronomers for its strong SZ effect and has been observed many times with radio telescopes. These observations revealed an uneven distribution of the hot gas in this galaxy cluster, which was not seen in X-ray observations. Astronomers therefore needed higher resolution observations; these however, were difficult to obtain with high-resolution radio interferometers as the hot gas in galaxy clusters is relatively smooth and widely-distributed. ...
The Sunyaev-Zel'dovich Effect at Five Arc-seconds: RXJ1347.5-1145 Imaged by ALMA - T. Kitayama et al
- Publications of the ASJ 68(5):88 (Oct 2016) DOI: 10.1093/pasj/psw082
arXiv.org > astro-ph > arXiv:1607.08833 > 29 Jul 2016