发表机构
University of Central Florida; Space Telescope Science Institute; Johns Hopkins University; University of Arizona（中佛罗里达大学; 太空望远镜科学研究所; 约翰斯·霍普金斯大学; 亚利桑那大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
我们构建了覆盖宽参数范围的褐矮星热辐射贡献函数网格，揭示云对发射深度的影响，并提供数据库和Web工具以辅助光谱观测规划与解释。
AI 中文摘要
我们展示了一组热辐射贡献函数及其对应的大气光谱模型，适用于有云和无云的褐矮星，覆盖有效温度 $T_{\rm eff} \in [500, 2000]$ K，表面重力 $\log g = [3.5, 5.5]$ [cgs]，沉降效率 $f_{\rm sed} = 1, 2, 3, 4$ 和 8，以及涡流扩散系数 $\log K_{\rm zz} = [6, 11]$。我们使用 Sonora Diamondback 模型的温度-压力廓线，结合 picaso 辐射传输代码和 virga 云建模代码，探索不同大气参数如何影响化学平衡大气中发射辐射的垂直分布。我们确认云的不透明度显著影响 CH$_4$、H$_2$O、CO、NH$_3$、CO$_2$ 等显著分子特征以及 Na 和 K 原子特征的大气发射深度。大气发射深度在 $J$ 波段以及 Na 和 K 双线的中分辨率光谱中变化最为显著。我们的分析强调了有云和无云大气在表征 L、L/T 过渡型和 T 型褐矮星时的压力-波长差异，并展示了贡献函数如何指导有针对性的光谱研究。为便于观测规划，我们提供了一个可访问的数据库和基于 Web 的应用程序，使社区能够将观测数据与我们的模型光谱和贡献函数网格（波长范围 0.5 - 30 $\mu$m）进行比较。
英文摘要
We present a grid of thermal emission contribution functions and their corresponding atmospheric spectra model for cloudy and cloud-free brown dwarfs, spanning effective temperatures $T_{\rm eff} \in [500, 2000]$ K, surface gravities $\log g = [3.5, 5.5]$ [cgs], sedimentation efficiencies $f_{\rm sed} = 1, 2, 3, 4$ and 8, and eddy diffusion coefficients $\log K_{\rm zz} = [6, 11]$. We use temperature-pressure profiles from the Sonora Diamondback models in conjunction with the picaso radiative transfer code and the cloud modeling code virga, to explore how different atmospheric parameters influence the vertical distribution of emitted radiation for atmospheres in chemical equilibrium. We confirm that cloud opacity significantly impacts atmospheric emission depth in prominent molecular features such as CH$_4$, H$_2$O, CO, NH$_3$, CO$_2$, and atomic features Na and K. The atmospheric emission depth varies most notably in the $J$-band, and at mid-resolution spectra in the Na and K doublets. Our analysis highlights pressure-wavelength differences between cloudy and cloud-free atmospheres for characterizing L, L/T transition, and T-type brown dwarfs and demonstrates how contribution functions can guide targeted spectroscopic investigations. To facilitate observational planning, we provide an accessible database and web-based application that enable the community to compare observational data with our model grid of spectra and contribution functions with a wavelength range of 0.5 - 30 $μ$m.
Comments31 pages, 22 figures, 3 tables. Accepted for publication in ApJ 29-Aug-2026. Model grid and web tool available at https://ltcfgrid.research.ucf.edu/ and on Zenodo (doi:10.5281/zenodo.17834338)
