[P-PS06] 月の科学と探査

[PPS06-10] 月面天文台：メートル波電波干渉計の実現に向けた概念検討

*岩田 隆浩¹、土屋 史紀²、山田 亨¹、磯部 直樹¹、関本 裕太郎¹、宮崎 康行¹、宇佐美 尚人¹、井口 聖³、高橋 慶太郎⁴、大西 利和⁵、山内 大介⁶ (1.宇宙航空研究開発機構　宇宙科学研究所、2.東北大学、3.国立天文台、4.熊本大学、5.大阪府立大学、6.神奈川大学)

キーワード：月面天文台、電波干渉計

The highly accurate observation in the lower frequency band below about 10 MHz is yet to be realized, so that this range is remarkable as one of the last frontiers for astronomy. This is mainly because that the terrestrial ionosphere prevents us from observing radio waves below the ionospheric cut-off frequency on the ground. It is, moreover, difficult to observe the faint radio waves from planets and celestial objects even on the earth's orbit because of the interference caused by solar bursts, artificial noises and terrestrial aurora emissions. The lunar far-side is a suitable site for such the lower frequency astronomical observations because noises from the Earth can always be avoided and radio waves from the Sun can be shielded during the lunar night.
One of the major targets of the astronomy on the lunar far-side is to realize the first detection of the 21-cm line of the neutral hydrogen from, so cold, the dark age of the universe. Emissions from extrasolar planets are also expected to be observed. In this paper, we report the progress of a conceptual study on a lunar astronomical observatory consisting of meter-wave radio interferometer on the lunar far-side. This observatory targets beyond 100 antennas extended to the maximum baseline of more than 100km, which provides the spatial resolution of about 1 arc-min at 10 MHz. We will also report about the feasibility study of the first-step pilot probe with three antenna units.