We have made the measurements of H₂-broadened line shape parameters of CH₄ transitions in the v₂+v₃ band located at 2.2 µm. These measurements support atmospheric opacity calculations of cold giant planets, hot Jupiters, and low mass brown dwarfs, for which H₂ is the dominant atmospheric constituent. For this reason, a series of spectra of pure CH₄ and CH₄H₂ mixtures were obtained in the Octad (4100–4600 cm⁻¹) region for a wide temperature range between 80 and 370 K using a Bruker 125HR high-resolution Fourier transform spectrometer (FTS) at Jet Propulsion Laboratory (JPL). Three custom-designed gas absorption cells vacuum-coupled to the FTS were used to obtain the spectra. All spectra were fit simultaneously using a multispectrum non-linear least-squares fitting software, which adopts a speed-dependent Voigt line shape using full line mixing taken into account through a relaxation matrix operation. H₂ pressure broadened half-widths, and H₂ pressure-induced shift coefficients were determined in 11 J-manifolds covering P(4) – R(6) plus the Q-branch. The temperature dependences of the width and shift coefficients were determined based upon the power law and the linear models. Collisional line mixing coefficients for CH₄H₂ were retrieved for ten transition pairs. For the same transitions, speed dependence parameters for the CH₄H₂ transitions were found to be smaller than for CH₄-air-broadening. We have compiled the retrieved line parameters in an electronic format and reported as supplemental document. This will facilitate the analyses of planetary and exoplanetary atmospheres using ground-, air- and space-based observations (e.g., Keck I and II, SOFIA, JWST).

我们已经对位于2.2 µm的v ₂ + v ₃带中CH ₄跃迁的H _2-扩展线形参数进行了测量。这些测量结果支持了冷的巨型行星，热的木星和低质量的棕矮星的大气不透明度计算，其中H ₂是主要的大气成分。因此，在八角（4100–4600 cm ^-1）中获得了一系列纯CH ₄和CH ₄ H ₂混合物的光谱。使用喷气推进实验室（JPL）的布鲁克125HR高分辨率傅里叶变换光谱仪（FTS）在80至370 K的宽温度范围内）真空耦合至FTS的三个定制设计的气体吸收池用于获得光谱。使用多光谱非线性最小二乘拟合软件同时拟合所有光谱，该软件采用依赖速度的Voigt线形，并通过松弛矩阵运算考虑了全线混合。H ₂压力加宽了一半宽度，H ₂压力引起的偏移系数在11个J流形中确定，覆盖P（4）– R（6）加上Q分支。根据幂定律和线性模型确定宽度和位移系数的温度依赖性。对于十个过渡对，获取了CH ₄ H _2的碰撞线混合系数。对于相同的转变，发现CH ₄ H ₂转变的速度依赖性参数小于CH _4-空气扩散的速度依赖性参数。我们已将检索到的线路参数汇编为电子格式，并作为补充文件进行了报告。这将有助于使用地面，空中和空间观测（例如， Keck I和II，SOFIA，JWST）。