Large area sky surveys of hydroxyl maser sources and establishment of their high precision trigonometry

2015 Fiscal Year Final Research Report

• Project/Area Number: 25610043
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: Kagoshima University
• Principal Investigator: IMAI Hiroshi 鹿児島大学, 理工学域理学系, 准教授 (70374155)
• Co-Investigator(Kenkyū-buntansha): ASAKI YOSHIHARU 国立天文台, 大学共同利用機関等, 准教授 (00332148) ; NAKANISHI HIROYUKI 鹿児島大学, 理工学研究科(理学系), 准教授 (90419846)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 水酸基メーザー / 高精度天体測量 / 広視野掃天観測 / 天の川銀河 / 星周ガス縁

Outline of Final Research Achievements

We have explored hydroxyl maser (microwave amplification by stimulated emission of radiation) sources, which are expected as important standard candles for the study on the structure of the Milky Way Galaxy and the kinematics of the Magellanic Clouds orbiting the Milky Way. Through unbiased sky survey, we have elucidated the true distribution of hydroxy maser sources in the Galactic plane, enabling us to precisely estimate the total number of visible hydroxy maser sources in the whole Milky Way. The estimated number is larger than expected. Moreover, we succeeded in trigonometric measurement for hydroxy maser sources by using a new data calibration technique on the Galactic scale. Thus we have been convinced that hydroxyl masers are quite useful for elucidating the dynamics of the Milky Way--Magellanic Clouds system and its history in the near future and we could taken great progress in developing effective strategy on maser surveys and high precision trigonometry.

Free Research Field

恒星・星間物理学