日本地球惑星科学連合2025年大会

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM11] Frontiers in solar physics

2025年5月26日(月) 17:15 〜 19:15 ポスター会場 (幕張メッセ国際展示場 7・8ホール)

コンビーナ:鳥海 森(宇宙航空研究開発機構 宇宙科学研究所)、Sterling Alphonse(NASA/MSFC)、渡邉 恭子(防衛大学校)、今田 晋亮(東京大学理学系研究科地球惑星科学専攻)

17:15 〜 19:15

[PEM11-P05] Testing a coronal heating model of the young Sun through Model-Observation Comparisons

*坂本 文平1庄田 宗人1今田 晋亮1 (1.東京大学大学院 理学系研究科 地球惑星科学専攻)

キーワード:太陽コロナ

The stellar corona is the primary source of stellar XUV (X-ray and extreme ultraviolet) emissions, which significantly influence planetary atmospheric evolution. Understanding the long-term history of the solar corona is essential for reconstructing the history of the solar system. A major challenge in estimating the young Sun’s high-energy emission is the difficulty of directly observing XUV radiation. Because of this, numerical modeling is essential for determining the emission rate.The purpose of this study is to examine whether a model, capable of reproducing the solar XUV emission, is applicable to young solar-type stars. To achieve this, we modeled the coronal emissions of solar-type stars with varying surface magnetic fluxes, where the surface magnetic flux serves as a proxy for stellar age. For each run, we computed the fluxes of emission lines over various formation temperatures. The emission line flux and surface magnetic flux follow a power-law relationship, with the index dependent on the line formation temperature. We observe that the power-law indices vary with formation temperature, following the same trend as in observations, where higher temperatures correspond to larger indices. Compared to previous studies, our findings demonstrate that the model can explain observations even in the wavelength range longer than 912 Å. Our results indicate that the current solar coronal heating model is applicable to young Sun, although further observational validations are necessary for a more comprehensive model assessment.