ALMA achieves unprecedented cosmic microwave background temperature measurement at redshift 0.89
A Keio University-led research team, working with the National Astronomical Observatory of Japan, has precisely measured the cosmic microwave background radiation (CMB) temperature at redshift z=0.89, corresponding to about 7 billion years ago, by analyzing archival Atacama Large Millimeter/submillimeter Array (ALMA) data targeting the quasar PKS1830-211. The CMB is faint primordial radiat