标题： 赫歇尔对原行星盘中气体的观测（GASPS）。 首次与大规模模型网格进行比较 显示英文标题

标题： The Herschel view of Gas in Protoplanetary Systems (GASPS). First comparisons with a large grid of models

摘要： 赫歇尔空间天文台的GASPS核心计划是一项针对原行星盘气相成分的调查，目标是240个具有广泛年龄、光谱类型和盘属性的对象。 为了分析这一大量数据，并启动原行星盘气体与尘埃性质的一致性研究，我们结合了辐射传递代码MCFOST和气体热平衡及化学代码ProDiMo的能力，计算出了一个包含300,000个盘模型的网格（DENT）。 我们展示了首次赫歇尔/GASPS线状数据和连续谱数据与DENT模型网格预测结果的对比。 我们的目标是测试DENT网格中已经识别出的一些主要趋势，同时定义更好的经验诊断方法来估算原行星盘的总气体质量。 对于赫比格星，光球紫外辐射似乎是主导的气体加热机制；而对于T Tauri星，紫外过量和/或X射线发射则占主导地位。 DENT网格揭示了远红外线分析的复杂性以及将这些观测结果反演为物理量的难度。 赫歇尔线状观测数据与连续谱数据和/或亚毫米波段旋转线（特别是CO线）相结合，对于详细表征恒星盘的物理和化学性质是必需的。 显示英文摘要

摘要： The Herschel GASPS Key Program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of protoplanetary discs, we have combined the capabilities of the radiative transfer code MCFOST with the gas thermal balance and chemistry code ProDiMo to compute a grid of 300 000 disc models (DENT). We present a comparison of the first Herschel/GASPS line and continuum data with the predictions from the DENT grid of models. Our objective is to test some of the main trends already identified in the DENT grid, as well as to define better empirical diagnostics to estimate the total gas mass of protoplanetary discs. Photospheric UV radiation appears to be the dominant gas-heating mechanism for Herbig stars, whereas UV excess and/or X-rays emission dominates for T Tauri stars. The DENT grid reveals the complexity in the analysis of far-IR lines and the difficulty to invert these observations into physical quantities. The combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and chemical properties of circumstellar discs.