One of the Roman Space Telescopes principal science objectives is to measure dark energy's equation-of-state using a strategic combination of imaging and spectroscopic surveys at high galactic latitude. Type Ia Supernovae survey requirements demand 0.3% photometric accuracy and calibration of key systematic effects. One of these is count rate dependent nonlinearity (CRNL) that if uncorrected affects the accuracy of SNe Ia distance measurements. Romans Relative Calibration System (RCS) enables on-orbit measurement and tracking of CRNL, through a direct illumination mode and a simultaneous lamp plus scene mode. We present results on the impact of CRNL calibration on the dark energy figure of merit (FoM), for a specific reduction of RCS capabilities. We examined many combinations of illumination and passbands, finding that only six meet the requirements. No RCS at all results in a factor of 5 degradation in the FoM.

罗马太空望远镜的主要科学目标之一是在高星系纬度使用成像和光谱调查的战略组合来测量暗能量的状态方程。Ia 型超新星调查要求 0.3% 的光度精度和关键系统效应的校准。其中之一是计数率相关非线性 (CRNL)，如果不加以校正，它将影响 SNe Ia 距离测量的准确性。Romans 相对校准系统 (RCS) 通过直接照明模式和同时灯加场景模式实现对 CRNL 的在轨测量和跟踪。我们展示了 CRNL 校准对暗能量品质因数 (FoM) 的影响的结果，以具体降低 RCS 能力。我们检查了照明和通带的许多组合，发现只有六个符合要求。完全没有 RCS 会导致 FoM 下降 5 倍。