Development of optical telescopes with nano-second time resolution and sub-miliarcsecond angular resolution

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K20929
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 16:Astronomy and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Saito Takayuki 東京大学, 宇宙線研究所, 准教授 (60713419)
• Co-Investigator(Kenkyū-buntansha): 猪目 祐介 東京大学, 宇宙線研究所, 技術職員 (90869710)
• Project Period (FY): 2020-07-30 – 2024-03-31
• Keywords: 時間領域天文学 / チェレンコフ望遠鏡 / 強度干渉計

Outline of Final Research Achievements

In order to use CTA Large Sized Telescope as a nano-second resolution optical telescope and an intensity interferometry device, it was necessary to reduce the dead time which takes at each readout. Also, there was a large room for improvement in the choice of photosensors. For the dead time problem, originally we planned to solve it by a modification of the readout board. However, we solved it differently. The analog output signal was extracted from the telescope and transferred via an optical fiber to the external data acquisition device. As for the improvement of photosensors, we tried to upgrade the current photomultiplier to SiPM. For that, it was necessary to develop a signal summation circuit, a signal shaping circuit, and a temperature compensation circuit. All of the three were successfully developed. However, we could not install them to the telescope.

Free Research Field

高エネルギー宇宙物理学

Academic Significance and Societal Importance of the Research Achievements

人間の目で宇宙を見上げても、宇宙の一部しか見えない。明るい部分しか見えないし、可視光しか知覚できないし、超高速変動も認識できない。一つ目を解決するのが光学望遠鏡、二つ目を解決するのが他波長望遠鏡、そして３つ目の解決を目指したのが本研究である。本研究をさらに発展させれば、また人類が知らない天体現象が見つかる可能性が大いにあり、人類の持つ宇宙像に修正が加わると期待できる。