Gas modelling in the disc of HD 163296
Gas modelling in the disc of HD 163296
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HD 163296 光盘中的气体建模
DOI：
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发表时间：
2011
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通讯作者：
M. Spaans
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作者：
I. Tilling;P. Woitke;P. Woitke;P. Woitke;G. Meeus;A. Mora;B. Montesinos;P. Riviere;C. Eiroa;Wing;A. Isella;A. Roberge;C. Martin;I. Kamp;C. Pinte;G. Sandell;William Vacca;F. Menard;I. Mendigut'ia;G. Duchêne;G. Duchêne;W. Dent;G. Aresu;R. Meijerink;M. Spaans
我们提出了详细的模型适合于观测的光盘around Herbig Ae星星HD 163296。这颗经过充分研究的天体的年龄为1400万年，有证据表明它有一个延伸到1540 Au的环星盘。我们使用辐射热化学光盘代码ProDiMo模拟气体和尘埃的拱星盘HD 163296，并试图通过拟合观测线和连续数据来确定盘的属性。其中包括作为开放时间关键计划GASPS（原行星系统中的气体）的一部分获得的新Herschel/PACS观测，包括对[Oi] 63µm线的探测和其他几条远红外线的上限。我们用连续谱数据和12 CO 3-2、2-1和13 CO J=1-0谱线跃迁以及H2 S（1）跃迁的地面观测数据补充了这一点。我们探讨了恒星紫外线变化和尘埃沉降对线发射以及衍生的圆盘性质的影响。我们的拟合结果导致推导出的气体/尘埃比在9-100的范围内，这取决于所作的假设。我们注意到，线通量一般是敏感的尘埃沉降的程度在光盘中，随着线通量的增加，沉降模式。这在内盘中的暖气体中形成的谱线中最为明显，但低激发分子谱线也受到影响。这对从线观测中推导盘状气体质量的尝试有着严重的影响。我们推导出相对于ISM水平的分数PAH丰度在0.007和0.04之间。在详细分析观测结果的基础上，利用恒星和紫外过量输入光谱，我们发现所有观测结果都与先前假设的圆盘几何相一致。
We present detailed model fits to observations of the disc aro und the Herbig Ae star HD 163296. This well-studied object has an age of∼ 4 Myr, with evidence of a circumstellar disc extending out to∼ 540 AU. We use the radiation thermo-chemical disc code ProDiMo to model the gas and dust in the circumstellar disc of HD 163296, and attempt to determine the disc properties by fitting to observational line and continuum data. These include new Herschel/PACS observations obtained as part of the open-time key program GASPS (Gas in Protoplanetary Systems), consisting of a detection of the [Oi] 63µm line and upper limits for several other far infrared lines. We complement this with continuum data and ground-based observations of the 12 CO 3-2, 2-1 and 13 CO J=1-0 line transitions, as well as the H 2 S(1) transition. We explore the effects of stellar ultraviolet variability and dust settling on the line emission, and on th e derived disc properties. Our fitting e fforts lead to derived gas/dust ratios in the range 9-100, depending on the assumptions made. We note that the line fluxes are sensitive in general to the degree of dust settli ng in the disc, with an increase in line flux for settled models. This is most pronoun ced in lines which are formed in the warm gas in the inner disc, but the low excitation molecular lines are also affected. This has serious implications for attempts to derive the disc gas mass from line observations. We derive fractional PAH abundances between 0.007 and 0.04 relative to ISM levels. Using a stellar and UV excess input spectrum based on a detailed analysis of observations, we find that the all observations are consiste nt with the previously assumed disc geometry.