The distribution of accretion rates as a diagnostic of protoplanetary disc evolution
The distribution of accretion rates as a diagnostic of protoplanetary disc evolution
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吸积率的分布作为原行星盘演化的诊断
DOI：
10.1093/mnras/stad1983
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发表时间：
2023
影响因子：
4.8
通讯作者：
Alexander R
中科院分区：
文献类型：
--
作者：
Alexander R
我们表明，观测到的吸积率分布是对原行星盘物理的一个强有力的诊断。由于角动量的湍流（“粘性”）传输导致的吸积与磁化盘风驱动的吸积的分布根本不同。我们发现，即使是在悲观的假设下，观测到的≥300个吸积率的均匀样本也足以在高可信度下区分这两种盘吸积机制。目前的金牛座T星吸积率样本没有这么大，而且还存在明显的不均匀性，因此粘性和风力驱动的模型与现有的观测结果基本一致。如果吸积是粘性的，观测到的吸积速率需要低的盘光蒸发速率（≤10−9M⊙yr−1）。因此，对恒星吸积率的统一、均匀的调查可以为原行星盘如何吸积这个长期存在的问题提供一个明确的答案。
We show that the distribution of observed accretion rates is a powerful diagnostic of protoplanetary disc physics. Accretion due to turbulent (‘viscous’) transport of angular momentum results in a fundamentally different distribution of accretion rates than accretion driven by magnetized disc winds. We find that a homogeneous sample of ≳300 observed accretion rates would be sufficient to distinguish between these two mechanisms of disc accretion at high confidence, even for pessimistic assumptions. Current samples of T Tauri star accretion rates are not this large, and also suffer from significant inhomogeneity, so both viscous and wind-driven models are broadly consistent with the existing observations. If accretion is viscous, the observed accretion rates require low rates of disc photoevaporation (≲10−9M⊙yr−1). Uniform, homogeneous surveys of stellar accretion rates can therefore provide a clear answer to the long-standing question of how protoplanetary discs accrete.