Study of brown dwarf atmosphere based on AKARI specctra

• Project/Area Number: 22540260
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Astronomy
• Research Institution: Japan Aerospace Exploration Agency
• Principal Investigator: YAMAMURA Issei 独立行政法人宇宙航空研究開発機構, 宇宙科学研究所, 准教授 (40322630)
• Project Period (FY): 2010 – 2012
• Project Status: Completed (Fiscal Year 2012)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2011: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2010: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 光学赤外線天文学 / スペース赤外線観測 / 褐色矮星 / 大気構造 / 赤外線分光 / あかり / 低温度星 / 二酸化炭素 / 近赤外線 / 赤外線分光観測 / 「あかり」 / 分子組成

Research Abstract

This research aims better understanding of physical and chemical condition in atmospheres of brown dwarfs, objects connecting stars and planets. Thanks to excellent quality near-IR spectra obtained by AKARI, we (1) confirmed that CO and CO2 abundances do not follow a standard theory, (2) found possible variation in elemental abundance among the objects, and (3) discussed radii of the dwarfs for the first time.

Research Products

• [Journal Article] ON THE RADII OF BROWN DWARFS MEASURED WITH AKARI NEAR-INFRARED SPECTROSCOPY (2013)
  • Author(s): S. Sorahana, I. Yamamura, H. Murakami
  • Journal Title: The Astrophysical Journal Volume: 767 Issue: 1 Pages: 77-81
  • DOI: 10.1088/0004-637x/767/1/77
  • Peer Reviewed
• [Journal Article] AKARI OBSERVATIONS OF BROWN DWARFS. III. CO, CO_2 and CH_4 FUNDAMENTAL BANDS AND PHYSICAL PARAMETERS (2012)
  • Author(s): S. Sorahana, I. Yamamura
  • Journal Title: The Astrophysical Journal Volume: 760 Issue: 2 Pages: 151-167
  • DOI: 10.1088/0004-637x/760/2/151
  • Peer Reviewed
• [Journal Article] NEW INSIGHT ON BROWN DWARF ATMOSPHERES REVEALED BY AKARI (2012)
  • Author(s): S. Sorahana, I. Yamamura
  • Journal Title: Publications of The Korean Astronomical Society Volume: 27 Issue: 4 Pages: 183-184
  • DOI: 10.5303/pkas.2012.27.4.183
  • Peer Reviewed
• [Journal Article] AKARI OBSERVATIONS OF BROWN DWARFS. II. CO_2 AS PROBEOF CARBON AND OXYGEN ABUNDANCE IN BROWN/ DWARFS. (2011)
  • Author(s): T. Tsuji, I. Yamamura, S. Sorahana
  • Journal Title: The Astrophysical Journal Volume: 734 Issue: 2 Pages: 73-80
  • DOI: 10.1088/0004-637x/734/2/73
  • Peer Reviewed
• [Journal Article] AKARI Observations of Brown Dwarfs. I. CO and CO2 Bands in the Near-Infrared Spectra (2010)
  • Author(s): Yamamura, I., Tsuji, T., Tanabe, T
  • Journal Title: The Astrophysical Journal Volume: 722 Issue: 1 Pages: 682-698
  • DOI: 10.1088/0004-637x/722/1/682
• [Journal Article] AKARI Observations of Brown Dwarfs.I.CO and CO_2 Bands in the Near Infrared Spectra (2010)
  • Author(s): 山村一誠
  • Journal Title: The Astrophysical Journal Volume: 722 Pages: 682-698
  • Peer Reviewed
• [Presentation] New Aspect of Brown Dwarf Atmospheres seen by AKARI (2012)
  • Author(s): Sorahana, S., Yamamura, I
  • Organizer: 17th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun,
  • Place of Presentation: バルセロナ貿易センター、スペイン
• [Presentation] 「あかり」による褐色矮星の近赤外線分光観測 VIII.スペクトル型に対する褐色矮星の半径の変化 (2012)
  • Author(s): 空華 智子, 山村 一誠
  • Organizer: 日本天文学会2012年秋季年会
  • Place of Presentation: 大分大学
• [Presentation] New Aspect of Brown Dwarf Atmospheres seen by AKARI (2012)
  • Author(s): Sorahana, S., Yamamura, I.
  • Organizer: 17th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun
  • Place of Presentation: The World Trade Center Barcelona
• [Presentation] 「あかり」による褐色矮星の近赤外線分光観測VII.:金属量をパラメータとしたスペクトルの解析 (2011)
  • Author(s): 空華智子
  • Organizer: 日本天文学会2011年秋期年会
  • Place of Presentation: 鹿児島大学
  • Year and Date: 2011-09-20
• [Presentation] 「あかり」による褐色倭星の近赤外線分光観測VI.:CO_2分子存在量の元素組成依存性 (2011)
  • Author(s): 山村一誠
  • Organizer: 日本天文学会2011年春季年会
  • Place of Presentation: 筑波大学
  • Year and Date: 2011-03-17
• [Presentation] AKARI Observations of Brown Dwarfs (2010)
  • Author(s): Yamamura, I.,
  • Organizer: 16th Cambridge Workshop on Cool Stars,
  • Place of Presentation: ワシントン大学、USA
• [Presentation] AKARI Observations of Brown Dwarfs (2010)
  • Author(s): 山村一誠
  • Organizer: 16th Cambridge Workshop on Cool Stars
  • Place of Presentation: ワシントン大学(米国)
• [Presentation] Analysis of CH4 Q-branch absorption in Brown Dwarf Spectra Observed by AKARI (2010)
  • Author(s): 空華智子
  • Organizer: 16th Cambridge Workshop on Cool Stars
  • Place of Presentation: ワシントン大学(米国)