On August 6, an interferometer test was conducted at the Array Operations Site (AOS) at 5000 m asl and fringes of 120 baselines were successfully obtained with sixteen 12-m antennas. In radio interferometer, radio wave is received by a pair of antennas and synthesized by computer. With 16 antennas, we can obtain fringes of 120 baselines from 120 pairs of antennas.

The target object used in this test is 3C279, an active galaxy with strong emission in the constellation Virgo.

The picture shows the ALMA staff celebrating the success of the interferometer test. The large sheet of paper held by the man in the middle of the front row is the results of the interferometer test. As you can see in the photo, East Asian young researchers are working actively in Chile and playing important roles for the progress of ALMA.

[Photographed by Kengo Tachihara (JAO/NAOJ)]