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

2015 Fiscal Year Final Research Report

• 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
• 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.

Free Research Field

太陽物理学