论文标题
对欧罗巴尾巴的可见波长光谱的内源性和外生贡献
Endogenic and Exogenic Contributions to Visible-wavelength Spectra of Europa's Trailing Hemisphere
论文作者
论文摘要
欧罗巴的尾随半球的组成反映了内源地质重塑和外源性硫辐射的综合影响。使用使用哈勃太空望远镜获得的Europa的空间分辨可见的波长光谱，我们绘制了整个后半球的多个光谱特征，并将其地理位置与大型地质，磁层轰炸和表面色的分布进行比较。基于这种比较，我们将光谱的某些方面解释为纯粹的外源硫辐射溶解产物和其他方面，是由内源物质和磁层硫的混合物形成的放射溶解产物。在我们的光谱中看到的两个吸收的空间分布 - 向近紫外线的广泛衰退和在530 nm处的独特特征 - 与以前从地面分光光度法中提出的硫同形同性恋者一致。但是，另外两个特征的地理位置 - 360 nm处的吸收特征和红色波长处的光谱斜率 - 与内源性物质更一致，而内源物质已通过硫辐射消化而改变。我们建议辐射的硫酸盐盐作为该材料的潜在候选物，但是我们无法用可用数据识别特定物种。
The composition of Europa's trailing hemisphere reflects the combined influences of endogenous geologic resurfacing and exogenous sulfur radiolysis. Using spatially resolved visible-wavelength spectra of Europa obtained with the Hubble Space Telescope, we map multiple spectral features across the trailing hemisphere and compare their geographies with the distributions of large-scale geology, magnetospheric bombardment, and surface color. Based on such comparisons, we interpret some aspects of our spectra as indicative of purely exogenous sulfur radiolysis products and other aspects as indicative of radiolysis products formed from a mixture of endogenous material and magnetospheric sulfur. The spatial distributions of two of the absorptions seen in our spectra -- a widespread downturn toward the near-UV and a distinct feature at 530 nm -- appear consistent with sulfur allotropes previously suggested from ground-based spectrophotometry. However, the geographies of two additional features -- an absorption feature at 360 nm and the spectral slope at red wavelengths -- are more consistent with endogenous material that has been altered by sulfur radiolysis. We suggest irradiated sulfate salts as potential candidates for this material, but we are unable to identify particular species with the available data.
