The Atacama Cosmology Telescope(ACT) is located on Cerro Toco at an altitude of 5200 meters in the Atacama Desert of northern Chile. It’s a 6m telescope which is designed to make high-resolution measurements of the cosmic microwave background (CMB) temperature and polarization anisotropies and detect massive galaxy clusters. The telescope is made of two parts. The secondary mirror is surrounded in the middle by the primary mirror and ground screen framing, which makes the whole telescope looks like a nest from outside. ACT firstly showed up at 22th October 2007.
So far it already has completed three seasons of observation and now is in the fourth season of observation. The ACT could observe light, radiation and identify on the order of a thousand galaxy clusters in the survey region. It could observe the oldest light in the universe and the cosmic microwave background(CMB), mapping them on arcminute to degree scales.
ATC had made enormous contributions to people’s understanding of cosmology. The observation of ATC from 2007 and 2013 was especially significant. From 2007 to 2011, ATC observed along two constant-declination strips on the sky: one running along the celestial equator, and the other along declination -55? in the southern sky. From the data ATC detected, scientist came out with “Temperature and Gravitational Lensing Power Spectrum Measurements From Thress Seasons of Data”, which is contributed to tightening the precision on many of fundamental parameters that characterize the universe.In 2012, scientists released “Evidence of Galaxy Cluster Motions with the Kinematic Sunyaev-Zel’dovich Effect” through the data ACT observed, which wined “Top Ten” of “PHYSICS WORLD Breakthrough for 2012”. It using high-resolution microwave sky maps made by the Atacama Cosmology Telescope.
It was the first evidence for motions of galaxy clusters and groups via microwave background temperature distortions due to the kinematic Sunyaev-Zel’dovich effect.