对新一代日冕空间可见光和近红外发射线观测的需要
The Need for a New Generation of Space-based Visible and Near-IR Emission Line Observations of the Corona
摘要：
可见光和近红外（V + NIR）发射线是在日全食期间首次在日冕中发现的，它们继续为研究日冕的物理特性提供独特的机会。现今最常观测到的日冕发射线是在极紫外线中，主要是碰撞激发的发射。另一方面，V + NIR线被辐射激发到高的日光投射距离。事实上，最近的日食观测已经证明了V + NIR谱线的诊断潜力，这些谱线至少在3.4 Rs之外仍然可以观察到。V + NIR谱线可用于推断关键等离子体参数，例如：电子和离子温度、磁场强度和形态、离子冻结距离、日冕等离子体的多普勒运动以及通过这些参数的时间变化来推断日冕物质抛射的动力学。目前和计划中的天基日冕仪，如太阳轨道器和Proba 3，将有一些V + NIR线的过滤器，但只有非常小的选择。因此，他们在推断电子或离子温度以及日冕的其他关键物理特性方面的能力将受到限制。地基DKIST和UCoMP将很快提供V + NIR线观测，但它们将被限制在约1.5 Rs的最大日光投射距离。为了更好地探索中日冕，并了解太阳风和空间天气事件的形成，我们必须部署更多的天基资产，以测量在日光投影距离超过1.5 Rs的V + NIR发射线的广泛选择。掩星可以通过传统的日冕仪、外部掩星仪等新方法、绕月轨道上的月球掩星或基于月球的月食观测（即，日全食（Total Solar Eclipse on the Moon）
英文摘要：
Visible and near-infrared (V+NIR) emission lines were the first to be discovered in the corona, during total solar eclipses, and they continue to offer unique opportunities to study the physical properties of the corona. The most commonly observed coronal emission lines today are in the extreme ultraviolet, which are dominated by collisionally excited emission. V+NIR lines on the other hand, are radiatively excited out to high helioprojective distances. Indeed, recent eclipse observations have demonstrated the diagnostic potential of V+NIR lines, which are still observable out to at least 3.4 Rs. V+NIR lines can be used to infer key plasma parameters such as: the electron and ion temperatures, magnetic field strength and morphologies, the ionic freeze-in distances, Doppler motions of coronal plasmas, and the dynamics of coronal mass ejections through time variations of these parameters. Current and planned space-based coronagraphs, such as Solar Orbiter and Proba 3, will have some filters for V+NIR lines, but will only have an exceptionally small selection. They will thus be limited in their ability to infer electron or ion temperatures, as well as other crucial physical properties of the corona. The ground-based DKIST and UCoMP will soon offer V+NIR line observations, but they will be limited to a maximum helioprojective distance of about 1.5 Rs. To better explore the middle corona, and to understand the formation of the solar wind and space weather events, it is essential that we deploy additional space-based assets to measure a wide selection of V+NIR emission lines at helioprojective distances beyond 1.5 Rs. Occulting of the solar disk could be achieved by a conventional coronagraph, by novel methods such as an external occulter, by lunar occultations in situ in orbit around the Moon, or by lunar based observations of lunar eclipses (i.e., total solar eclipse on the Moon).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
