Surveys and high resolution imaging of jets from evolved stars

2010 Fiscal Year Final Research Report

• Project/Area Number: 20540234
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Astronomy
• Research Institution: Kagoshima University
• Principal Investigator: IMAI Hiroshi Kagoshima University, 理工学研究科(理学系), 准教授 (70374155)
• Co-Investigator(Kenkyū-buntansha): DEGUCHI Shuji 国立天文台, 野辺山宇宙電波観測所, 准教授 (20197825)
• Co-Investigator(Renkei-kenkyūsha): HIROTA Tomoya 国立天文台, 水沢VLBI観測所, 助教 (10325764) ; HONMA Mareki 国立天文台, 水沢VLBI観測所, 准教授 (20332166) ; NAKAGAWA Akiharu 鹿児島大学, 理工学研究科(理学系), 助教 (60535631)
• Research Collaborator: NAKASHIMA Jun-ichi 香港大学, 理学部, 助理教授 ; KWOK Sun 港大学, 理学部, 教授 ; HE Jin-Hua 雲南天文台(中国), 研究員 ; DIAMOND Philip J. Commonwealth Scientific and Industrial Research Organisation (オーストラリア), 教授 ; UKITA Nobuharu 国立天文台, 光赤外研究部, 准教授 ; SAKAI Tsuyoshi 東京大学, 天文教育研究センター, プロジェクト助教 ; TAFOYA Daniel 鹿児島大学, 大学院・理工学研究科, 日本学術振興会外国人研究員
• Project Period (FY): 2008 – 2010
• Keywords: 電波天文学

Research Abstract

We have studied the "water fountain" sources that exhibit bipolar fast jets traced by water vapor maser emission and associated with evolved star. We found a "helix" pattern of jet from one the water fountains and obtained its annual parallax distance. In another source, we found high velocity components of carbon-monoxide emission and an extremely low ^<12>CO/^<13>CO intensity ratio. These results suggest that the parental stars of the water fountains should be intermediate-mass (2-8 solar masses) stars and the jets should play a major role to shape planetary nebulae.

Research Products

• [Journal Article] Annual Parallax Distance and Kinematical Property of H_2O Masers in IRAS 19312+1950 (2011)
  • Author(s): Imai H., Tafoya, D., Hirota, T., Honma, M., Miyaji, T.
  • Journal Title: Publ.Astron.Soc.Japan 63,No.1 Pages: 81-87
  • Peer Reviewed
• [Journal Article] Measurement of the Distance and Proper Motions of the H_2O Masers in the Young Planetary Nebula K 3-35 (2011)
  • Author(s): Tafoya, D., Imai, H., GOmez, Y., Torrelles, J.M., Patel, N.A., Anglada, G, Miranda, L.F., Honma, M., Hirota, T., Miyaji, T.
  • Journal Title: Publ.Astron.Soc.Japan 63,No.1 Pages: 71-80
  • Peer Reviewed
• [Journal Article] Maser Properties of the Enigmatic IRAS Source 19312+1950 (2011)
  • Author(s): Nakashima, J., Deguchi, S., Imai, H., Kemball, A., Lewis, B.M.
  • Journal Title: Astrophys.J. 728 Pages: 76-89
  • Peer Reviewed
• [Journal Article] Japanese VLBI Network Mapping of SiO_v=3 J=1-0 Maser Emission in W Hydrae (2010)
  • Author(s): Imai, H., Nakashima, J., Deguchi, S., Yamauchi A., Nakagawa, A., Nagayama, T.
  • Journal Title: Publ.Astron.Soc.Japan 62,No.2 Pages: 431-439
  • Peer Reviewed
• [Journal Article] CO J=3-2 Emission from the "Water Fountain" Sources IRAS 16342-3814 and IRAS 18286-0959 (2009)
  • Author(s): Imai H., He, J.-H., Nakashima, J., Ukita, N., Deguchi, S., Koning, N.
  • Journal Title: Publ.Astron.Soc.Japan 61,No.6 Pages: 1365-1372
  • Peer Reviewed
• [Journal Article] First detection of CO lines in a water fountain star (2008)
  • Author(s): He, J.-H., Imai, H., Hasegawa, T.I., Campbell, S.W., Nakashima, J.
  • Journal Title: Astron.Astrophys. 48 Pages: L21-L24
  • Peer Reviewed
• [Presentation] VLBI Mapping of Multiple Maser Lines with the East Asia VLBI Network (2010)
  • Author(s): 今井裕
  • Organizer: Asian-Pacific Radio Science Conference 2010
  • Place of Presentation: 富山
  • Year and Date: 20100900
• [Presentation] VERAプロジェクトチーム"惑星状星雲K3-35にイ寸随する水メーザー源の年周視差計測 (2010)
  • Author(s): 今井裕
  • Organizer: 日本天文学会春季年会
  • Place of Presentation: 広島
  • Year and Date: 20100300
• [Presentation] 一酸化珪素メーザー v=3 J=1-0輝線のVLBIによる初撮像 (2009)
  • Author(s): 今井裕、出口修至、中川亜紀治、永山匠、山内彩
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 山口
  • Year and Date: 20090900
• [Presentation] 「宇宙の噴水」天体からのCO J=3-2輝線の検出 (2008)
  • Author(s): 今井裕、Jin-Hua He, 中島淳一、出口修至
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 岡山
  • Year and Date: 20080900
• [Presentation] OH maser envelopes of the 'water fountain' sources (2008)
  • Author(s): 今井裕
  • Organizer: 9th European VLBI Network Symposium
  • Place of Presentation: イタリア・ボローニヤ
  • Year and Date: 20080900
• [Remarks] ホームページ等
  • URL: http://milkyway.sci.kagoshima-u.ac.jp/~imai