论文标题
从增强Protostars II的预序序模型的脉冲不稳定。建模$δ$ scuti星的梯形图，而无需旋转分裂
Pulsational instability of pre-main-sequence models from accreting protostars II. Modelling echelle diagrams of $δ$ Scuti stars without rotational splitting
论文作者
论文摘要
早期恒星进化的物理学（例如积聚过程）通常不正确地包括在预定序列模型的计算中，从而导致模型网格不足，从而导致结果中的系统错误。我们的目的是研究用于序列前序列恒星的星介异常建模的当前和改进的方法。我们计算了包括早期增生阶段的序列序列模型的广泛网格，并使用所得的平衡模型作为计算理论频谱的输入。这些光谱用于研究建模梯形图以找到最可靠的方法的不同方法。通过应用Petersen图，我们提出了一种简单的算法，以从观察到的脉动频率中提取梯形图。我们表明，具有不足输入物理和不完善的建模方法的模型网格导致提取的恒星参数中低估的不确定性和系统错误。我们对HD 139614的重新讨论导致的恒星参数与Murphy等人得出的参数不同。 （2021）。我们通过应用Akaike和贝叶斯信息标准进行了先前研究和结果之间的模型比较。尽管与我们的10-D模型有关的结果尚无定论，但它们（非常）具有固定积聚参数的6-D模型的强有力证据（导致与10-D模型几乎相同的恒星参数）比Murphy等人所采用的模型所优选。 （2021）。通常，我们的建模方法可以对恒星参数（Δr〜0.05 r_ \ odot，Δlogg <〜0.01和Δm_\ star〜0.1 m_ \ odot）提供狭窄的约束。经过广泛测试的建模方法和自动提取梯形图应使我们将来能够研究更多的预序列序列Delta Scuti恒星，并导致可靠的恒星参数。
The physics of early stellar evolution (e.g. accretion processes) is often not properly included in the calculations of pre-main-sequence models, leading to insufficient model grids and hence systematic errors in the results. We aim to investigate current and improved approaches for the asteroseismic modelling of pre-main-sequence delta Scuti stars. We calculated an extensive grid of pre-main-sequence models including the early accretion phase and used the resulting equilibrium models as input to calculate theoretical frequency spectra. These spectra were used to investigate different approaches in modelling echelle diagrams to find the most reliable methods. By applying Petersen diagrams, we present a simple algorithm to extract echelle diagrams from observed pulsation frequencies. We show that model grids with insufficient input physics and imperfect modelling approaches lead to underestimated uncertainties and systematic errors in the extracted stellar parameters. Our re-discussion of HD 139614 leads to different stellar parameters than the ones derived by Murphy et al. (2021). We performed a model comparison between this previous investigation and our results by applying the Akaike and Bayesian information criteria. While the results with regard to our 10-d model are inconclusive, they show (very) strong evidence of a 6-d model with fixed accretion parameters (leading to almost identical stellar parameters to those of the 10-d model) to be preferred over the model applied by Murphy et al. (2021). In general, our modelling approach can provide narrow constraints on the stellar parameters (ΔR ~ 0.05 R_\odot, Δlog g <~ 0.01, and ΔM_\star ~ 0.1 M_\odot). The extensively tested modelling approaches and automatic extraction of echelle diagrams should allow us to study many more pre-main-sequence delta Scuti stars in the future and lead to reliable stellar parameters.
