Osaka Prefecture University

Osaka Prefecture University Radiotelescope Used for First Radio Inferometer Measurements in Japan at frequency band of 230GHz

LastUpDate: July 06, 2015

Osaka Prefecture University Radiotelescope Used for First Radio Inferometer Measurements in Japan at frequency band of 230GHz

-A Step Toward Measuring Black Holes-

A joint research by the Astrophysics Laboratory of the Osaka Pre1fecture University Graduate School of Science, Yamaguchi University, the National Astronomical Observatory of Japan (NAOJ), the Institute of Space and Astronautical Science (ISAS), the National Institute of Information and Communications Technology (NICT), Ibaraki University and Kyoto University succeeded in Japan’s first 230 GHz band very-long-baseline inferometry (VLBI) measurements. With the cooperation of the NAOJ, the Astrophysics Laboratory developed and operated two 230 GHz radiotelescopes, the OPU 1.85m and the SPART 10m telescope(Photo1). Experiments are currently underway using these two telescopes.

Black holes are known as astronomical bodies of such supergravity that they attract everything, even light itself. Their existence has been confirmed indirectly by a few different methods, but never directly. Confirming the existence of black holes is an important area of research.

Very long baseline inferometry (VLBI) is a promising way to definitely prove the existence of black holes. We have increased the angular resolution which in VLBI is proportional to the radio frequency used and which is an indicator of how well you can discriminate the object. To detect black holes it is estimated that we need a signal of at least 230 GHz. In previous VLBI measurements in Japan we had achieved signals of only about 86 GHz, but now we have caught up with the standard of the world.

By amassing the power of VLBI astronomy all over the country, this research has rapidly improved VLBI technology in Japan and has been an opportunity for Japan to make a great contribution to an international research area, of black hole detection.

(Photo1) Very long baseline inferometry at the Nobeyama Radio Observatory

In one corner of the Nobeyama Observatory a 1.85m radiotelescope and the SPART radiotelescope are installed 150m apart. By summing the signals from both, extremely high angular resolution can be achieved.

Contact:

Project Professor Hideo Ogawa

Associate Professor Hiroyuki Maezawa

Astrophysics Laboratory, Graduate School of Science, Osaka Prefecture University

Tel +81-72-254-9726,+81-72-254-7674