GROUND-BASED OBSERVATION OF VISIBLE AURORA ON JUPITER BY SPECTROSCOPIC IMAGING WITH NARROW BANDPASS

1. 利用高色散回声光谱仪（HIDES）和188cm望远镜对冈山天体物理观测站获得的木星可见极光观测结果进行了详细的检验，发现在木星南极区域有Hα极光的边缘（S/N ~ 1）探测。在详细分析2004年和2005年在haleakala山用Fabry-Perot干涉仪观测结果的基础上，得到了Io等离子体环面中硫离子发射强度、硫离子体速度及其与自转速度的偏差以及垂直于和平行于磁力线的离子温度的二维分布。从这些结果可以清楚地看出，在远离木卫一的区域内，向木卫一环提供的等离子体相当均匀，而且其数量每年都在变化。此外，利用3.7m AEOS望远镜耦合的Fabry-Perot干涉仪观测了木卫一附近钠原子的共振散射。对数据的详细分析表明，在木卫一的木星面和反木星面，钠原子的分布是不对称的。通过对钠原子共振散射的观察和计算机模拟，发现溅射、解离和分子离子的解离重组是产生高速钠原子的主要过程。

1. Detailed examination of observation results on Jupiter visible aurora obtained at Okayama Astrophysical Observatory with High Dispersion Echell Spectrograph (HIDES) coupled with a 188-cm telescope revealed marginal (S/N〜1) detection of Hα aurora in the southern polar region of Jupiter.2. Based on detailed analysis of observation results obtained at Mt.Haleakala using a Fabry-Perot interferometer in 2004 and 2005, two-dimensional distributions of sulfur ion emission intensity, bulk velocities of sulfur ions and their deviation from the corotation velocity in Io plasma torus were obtained as well as ion temperatures perpendicular and parallel to the magnetic field line. From these results, it became clear that plasma supply to the Io torus is considerably uniform in a region away from Io, and that its amount is variable from year to year. In addition, resonant scattering of sodium atoms in the close proximity to Io was observed by using the Fabry-Perot interferometer coupled to a 3.7m AEOS telescope. Detailed analysis of the data showed that distribution of sodium atoms are asymmetric with respect to Io's Jupiter side and anti-Jupiter side.3. Based on observation of resonant scattering of Iogenic sodium atoms and computer simulation, sputtering and dissociation and dissociative recombination of molecular ion are found to be the dominant processes for producing high-velocity sodium atoms.