标题： 具有多孔尘埃消光系数的原行星盘中的尘埃质量 显示英文标题

标题： Dust mass in protoplanetary disks with porous dust opacities

摘要： 阿塔卡马大型毫米/亚毫米阵列（ALMA）的观测表明，在假设毫米波连续辐射是光学薄的情况下，原行星盘的质量不足以形成已知的系外行星群体。 在这项工作中，我们研究了在辐射传递模型中考虑尘埃颗粒的孔隙度如何影响质量的确定。 结果显示，具有多孔尘埃消光特性的盘面产生相似的尘埃温度，但毫米波流量系统性地低于包含致密尘粒的盘面。 此外，我们重新校准了广泛范围的恒星参数下尘埃温度与恒星亮度之间的关系，并使用传统的解析方法计算了一大批盘面的尘埃质量。 我们的计算所得中值尘埃质量约为文献结果的6倍，这主要由多孔和致密颗粒的不同消光特性驱动。 盘面尘埃质量和系外行星质量之间累积分布函数的比较显示，如果颗粒是多孔的，则中值系外行星质量约为中值尘埃质量的二分之一，并且没有系外行星系统的质量高于最巨大的盘面。 我们的分析表明，采用多孔尘埃消光特性可能缓解了行星形成的质量预算问题。 作为一个例子，用来说明光学深度和多孔尘埃消光特性对质量估算的综合影响，我们对IRAS 04370+2559盘面进行了新的IRAM/NIKA-2观测，并对其能谱能量分布进行了详细的辐射传递建模。 最佳拟合的尘埃质量大约比传统解析计算的结果高100倍。 未来需要在不同波长上进行空间分辨观测，以更好地限制尘埃质量。 显示英文摘要

摘要： ALMA surveys have suggested that protoplanetary disks are not massive enough to form the known exoplanet population, under the assumption that the millimeter continuum emission is optically thin. In this work, we investigate how the mass determination is influenced when the porosity of dust grains is considered in radiative transfer models. The results show that disks with porous dust opacities yield similar dust temperature, but systematically lower millimeter fluxes compared to disks incorporating compact dust grains. Moreover, we recalibrate the relation between dust temperature and stellar luminosity for a wide range of stellar parameters, and calculate the dust masses of a large sample of disks using the traditionally analytic approach. The median dust mass from our calculation is about 6 times higher than the literature result, and this is mostly driven by the different opacities of porous and compact grains. A comparison of the cumulative distribution function between disk dust masses and exoplanet masses show that the median exoplanet mass is about 2 times lower than the median dust mass, if grains are porous, and there are no exoplanetary systems with masses higher than the most massive disks. Our analysis suggests that adopting porous dust opacities may alleviate the mass budget problem for planet formation. As an example illustrating the combined effects of optical depth and porous dust opacities on the mass estimation, we conduct new IRAM/NIKA-2 observations toward the IRAS 04370+2559 disk and perform a detailed radiative transfer modeling of the spectral energy distribution. The best-fit dust mass is roughly 100 times higher than the value from the traditionally analytic calculation. Future spatially resolved observations at various wavelengths are required to better constrain the dust mass.