On September 2, an interferometer test was conducted with the first Japanese 7-m and first 12-m antennas at the Array Operations Site (AOS) at 5000 m asl and interference fringes were successfully detected.

The target object is a quasar 0538-044, located in the constellation Pictor about 7.3 billion years away.

This is the first successful interferometer test with two antennas of different diameters (7-m and 12-m) at the AOS, although we had already confirmed their linkage at the Operations Support Facility (OSF) at 2900 m asl. The test results demonstrate that Japanese 7-m antennas are ready for operation as part of the ALMA telescope.

The picture shows observation staff members. Kouichiro Nakanishi (second from right), CSV scientist at the Joint ALMA Observatory (JAO), is showing the test results.
[Photographed by Gamel Martinez (JAO)]