Motivated by the development of high-dispersion spectrographs in the mid-infrared (MIR) range, we study their application to the atmospheric characterization of nearby nontransiting temperate terrestrial planets around M-type stars. We examine the detectability of CO₂, H₂O, N₂O, and O₃ features in high-resolution planetary thermal emission spectra at 12–18 μm assuming an Earth-like profile and a simplified thermal structure. The molecular line width of such planets can be comparable to or broader than the Doppler shift due to the planetary orbital motion. Given the likely difficulty in knowing the high-resolution MIR spectrum of the host star with sufficient accuracy, we propose observing the target system at two quadrature phases and extracting the differential spectra as the planetary signal. In this case, the signals can be substantially suppressed compared with the case where the host star spectrum is perfectly known, as some parts of the spectral features do not remain in the differential spectra. Despite this self-subtraction, the CO₂ and H₂O features of nearby (≲5 pc) systems with mid-/late-M host stars would be feasible with a 6.5 m class cryogenic space telescope, and orbital inclination could also be constrained for some of them. For CO₂ and N₂O in a 1 bar Earth-like atmosphere, this method would be sensitive when the mixing ratio is 1–10³ ppm. The detectability of molecules except O₃ is not significantly improved when the spectral resolution is higher than , although the constraint on the orbital inclination is improved. This study provides some benchmark cases useful for assessing the value of MIR high-resolution spectroscopy in terms of characterization of potentially habitable planets.

受到中红外（MIR）范围内高色散光谱仪的发展的推动，我们研究了它们在M型恒星周围附近的非过渡温带地球行星的大气特征中的应用。我们检查CO的可检测₂，H ₂ O，N ₂ O，和O _3层的特征在高分辨率行星热发射光谱在12-18 μm假定具有类地剖面和简化的热结构。由于行星轨道运动，这种行星的分子线宽度可以与多普勒频移相当或比其宽。鉴于很难以足够的精度了解主恒星的高分辨率MIR光谱，我们建议在两个正交相位上观测目标系统，并提取差分光谱作为行星信号。在这种情况下，由于光谱特征的某些部分没有保留在微分光谱中，因此与完全了解主星光谱的情况相比，可以基本上抑制信号。尽管有这种自我减法，CO ₂和H ₂具有6.5 m级低温太空望远镜的附近（≲5pc）系统具有中/晚M个主星的其他功能将是可行的，并且其中一些轨道的倾斜也可能受到限制。对于在1 bar的类地大气中的CO ₂和N ₂ O，当混合比为1–10 ³ ppm时，此方法将很灵敏。当光谱分辨率高于时，除O ₃以外的分子的可检测性没有明显改善，尽管改善了对轨道倾角的约束。这项研究提供了一些基准案例，可用于从潜在宜居行星的表征方面评估MIR高分辨率光谱学的价值。