The Line Emission Mapper X-ray Probe-class mission concept is based on a microcalorimeter array tuned to energies in the range 0.1 to 2 keV. The study of cosmic ecosystems defines the directed portion of the Line Emission Mapper (LEM) mission, thus LEM has been optimized for observations of diffuse X-ray-emitting gas, largely with very low surface brightness. To broaden the range of targets that general observers can study with LEM, we have investigated the particular needs for UV/optical bright stars and solar-system objects. X-ray microcalorimeters are susceptible to degraded energy resolution that can result from thermal noise from residual UV, optical, and IR radiation. Using the present baseline design of the microcalorimeter thermal filters, we compute the UV-IR loading expected from bright stars over the effective temperature range 3500 to 39,000 K and from solar-system objects. The dominant leak of out-of-band energy is in the far-UV around 1500 Å, with a secondary peak of throughput around 4000 Å. For stars with magnitudes V<10 and for all solar-system planets as well as the Moon, the loading is significant, indicating that additional UV/optical blocking is essential if bright objects are to be observed. We have investigated the efficacy of several filter options for optical-blocking filters on the LEM filter wheel, demonstrating that new technology development is not necessary to open up many of these classes of objects to investigation with the high spectral resolution of LEM.

中文翻译：

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将线发射测绘仪的高分辨率 X 射线光谱扩展到紫外/光学明亮源

线发射测绘仪 X 射线探针级任务概念基于调谐至 0.1 至 2 keV 范围内能量的微量热计阵列。对宇宙生态系统的研究定义了线发射测绘器 (LEM) 任务的定向部分，因此 LEM 已针对扩散 X 射线发射气体的观测进行了优化，主要是表面亮度非常低的气体。为了扩大普通观测者可以使用 LEM 研究的目标范围，我们研究了紫外线/光学明亮恒星和太阳系物体的特殊需求。X 射线微量热计很容易受到能量分辨率下降的影响，这是由残余紫外线、光学和红外线辐射的热噪声造成的。使用微热量计热过滤器的现有基线设计，我们计算了有效温度范围 3500 至 39,000 K 的明亮恒星和太阳系物体的预期 UV-IR 负载。带外能量的主要泄漏位于 1500 Å 左右的远紫外区域，吞吐量的次要峰值约为 4000 Å。对于视星等 V<10 的恒星以及所有太阳系行星以及月球来说，载荷很大，这表明如果要观测明亮的物体，额外的紫外线/光学阻挡是必不可少的。我们研究了 LEM 滤光轮上光学阻挡滤光片的几种滤光片选项的功效，证明新技术的开发并不需要开发许多此类物体来利用 LEM 的高光谱分辨率进行研究。