Establishment of the novel diagnostic tool of magnetic field via the Hanle effect

• Project/Area Number: 25887051
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Ryohko Ishikawa 国立天文台, ひので科学プロジェクト, 助教 (00709636)
• Project Period (FY): 2013-08-30 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 太陽物理学 / プラズマ・核融合 / 偏光 / 磁場

Outline of Final Research Achievements

We established a procedure to infer the magnetic field using the Hanle effect, which will enable us to diagnose the magnetism in solar chromosphere and the transition region. By mimicking the inversion of the linear polarization profiles of the hydrogen Lyman-alpha line (121.6 nm) that is the targeting spectrum of the sounding rocket experiment CLASP (launch in FY 2015), we investigated the range of magnetic field sensitive to the Hanle effect, ambiguity and uncertainty in the inversion, and the influence of atmospheric model on the results. The most important result is that it is difficult to uniquely determine the magnetic parameters only from the CLASP observables (i.e., linear polarization profiles), and simultaneous measurements to constrain one of parameters are critically important. Based on our study, we completed the planning of the CLASP experiment including the coordinated observation with other instruments, and investigated the future direction of the Hanle diagnostics.

Research Products

• [Int'l Joint Research] National Solar Observatory(米国)
• [Int'l Joint Research] Instituto de Astrofisica de Canarias(スペイン)
• [Journal Article] ON THE INVERSION OF THE SCATTERING POLARIZATION AND THE HANLE EFFECT SIGNALS IN THE HYDROGEN Lyα LINE (2014)
  • Author(s): R. Ishikawa, A. Asensio Ramos, L. Belluzzi, R. Manso Sainz, J. Stepan, J. Trujillo Bueno, M. Goto, and S. Tsuneta
  • Journal Title: The Astrophysical Journal Volume: 787 Issue: 2 Pages: 159-169
  • DOI: 10.1088/0004-637x/787/2/159
  • Peer Reviewed
• [Presentation] CLASP: A UV Spectropolarimeter on a Sounding Rocket for Probing the Chromosphere-Corona Transition Region (2015)
  • Author(s): R. Ishikawa et al.
  • Organizer: IAU XXIX General Assembly・Division E Science Meeting
  • Place of Presentation: アメリカ合衆国・ハワイ州・ホノルル
  • Year and Date: 2015-08-10
  • Int'l Joint Research / Invited
• [Presentation] CLASP sounding rocket experiment for probing the magnetic field in the upper chromosphere and the transition region (2015)
  • Author(s): R. Ishikawa and CLASP team
  • Organizer: ISSI workshop: Sub-arcsec Observations and Interpretation of the Chromosphere
  • Place of Presentation: スイス・ベルン
  • Year and Date: 2015-07-21
  • Int'l Joint Research / Invited
• [Presentation] ハンレ効果を用いた磁場診断の大気モデル依存性について (2015)
  • Author(s): 石川遼子、後藤基志、飯田佑輔、常田佐久
  • Organizer: 日本天文学会2015年春季年会
  • Place of Presentation: 大阪大学（大阪府、大阪市）
  • Year and Date: 2015-03-20
• [Presentation] 量子力学的ハンレ効果を用いた彩層～遷移層の磁場診断手法について (2014)
  • Author(s): 石川遼子
  • Organizer: 太陽研連シンポジウム「活動極大期を迎えた太陽研究の新たな展開 ---彩層プラズマ診断、宇宙天気、Solar-C---」
  • Place of Presentation: 京都府京都市, 京都大学理学研究科セミナーハウス
  • Invited
• [Presentation] 量子力学的ハンレ効果を用いた彩層～遷移層の磁場診断手法の検討 (2014)
  • Author(s): 石川遼子, A. Asensio Ramos, R. Manso Sainz, J. Trujillo Bueno, L. Belluzzi, J. Stepan, 後藤基志, 常田佐久, and the CLASP team
  • Organizer: 日本天文学会2014年春季年会
  • Place of Presentation: 東京都三鷹市, 国際基督教大学
• [Presentation] New diagnostic tool for magnetic fields in low-β plasma: CLASP (2013)
  • Author(s): Ryohko Ishikawa
  • Organizer: The Seventh Hinode Science Meeting
  • Place of Presentation: 岐阜県高山市, 飛騨・世界生活文化センター