Atacama B-Mode Search

The Atacama B-Mode Search (ABS) was an astronomical survey of the cosmic microwave background (CMB) in search of B-mode CMB polarization, carried out from 2012 to 2014 on a special-purpose telescope (ABS telescope) operating on the Atacama Plateau, located at the same site as the Atacama Cosmology Telescope (ACT). The survey had the nominal goal of discovering B-modes due to inflationary gravitational waves, but realistically was a test of equipment and methods and a source of data for combined analysis (cross-correlations) and to strengthen existing conclusions.