On the Effects of Self-obscuration in the (Sub)Millimeter Spectral Indices and the Appearance of Protostellar Disks
On the Effects of Self-obscuration in the (Sub)Millimeter Spectral Indices and the Appearance of Protostellar Disks
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DOI：
10.3847/1538-4357/aae779
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发表时间：
2018-10
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通讯作者：
R. Galv'an-Madrid;H. Liu;A. Izquierdo;A. Miotello;B. Zhao;C. Carrasco-Gonz'alez;S. Lizano;Luis F. Rodríguez
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作者：
R. Galv'an-Madrid;H. Liu;A. Izquierdo;A. Miotello;B. Zhao;C. Carrasco-Gonz'alez;S. Lizano;Luis F. Rodríguez
在本文中，我们探讨了自遮蔽的影响，在原恒星盘径向降低的温度梯度和较冷的中平面。我们的动机是最近的报告，解决黑暗的车道（“汉堡包”）和（亚）毫米光谱指数系统低于ISM值的光学薄尘埃，αISM = 3.7。我们探索了几个模型网格，缩放盘质量和变化的倾斜角i和观察频率ν从VLA Ka波段（137 GHz）到阿尔马波段8（1405 GHz）。我们还考虑了将（亚）毫米尘埃不透明度幂律指数β从1.7降低到1的影响。我们发现，需要一个在Mdisk = 0.01-2 M Ω范围内的盘质量分布来再现观测到的光谱指数分布，并且假设固定的β = 1.7给出比β = 1更好的结果。为了产生α ×10的一些情况，还需要盘质量的广泛分布，并且与最近的流体动力学模拟一致。虽然我们不排除在短的原恒星时间尺度内发生一些晶粒生长的可能性，但我们得出结论，需要考虑到自遮蔽。
In this paper we explore the effects of self-obscuration in protostellar disks with a radially decreasing temperature gradient and a colder midplane. We are motivated by recent reports of resolved dark lanes (“hamburgers”) and (sub)millimeter spectral indices systematically below the ISM value for optically thin dust, αISM = 3.7. We explore several model grids, scaling disk mass and varying inclination angle i and observing frequency ν from the VLA Ka band (∼37 GHz) to ALMA Band 8 (∼405 GHz). We also consider the effects of decreasing the index of the (sub-)millimeter dust opacity power-law β from 1.7 to 1. We find that a distribution of disk masses in the range Mdisk = 0.01–2 M⊙ is needed to reproduce the observed distribution of spectral indices, and that assuming a fixed β = 1.7 gives better results than β = 1. A wide distribution of disk masses is also needed to produce some cases with α ×10, and are consistent with recent hydrodynamical simulations. Although we do not rule out the possibility of some grain growth occurring within the short protostellar timescales, we conclude that self-obscuration needs to be taken into account.