标题： 原行星盘中的多孔尘埃颗粒：应用于HL Tau盘 显示英文标题

标题： Porous Dust Particles in Protoplanetary Disks: Application to the HL Tau Disk

摘要： 基于射电干涉仪观测的尘埃连续谱和偏振观测所约束的尘埃颗粒大小彼此至少相差一个量级。 受小行星和其他太阳系小天体（例如罗塞塔任务观测到的）多孔尘埃的启发，我们研究了尘埃颗粒的孔隙率如何影响这两种方法估算出的颗粒大小。 多孔颗粒具有较低的折射率，这会影响尘埃的吸收率和偏振分数。 由于米氏干涉图样较弱，如果颗粒尺寸超过几百微米，多孔颗粒在毫米波段的吸收率比致密颗粒低。 因此，使用多孔颗粒推断的尘埃质量可以高出六倍。 致密颗粒与多孔颗粒之间最显著的区别在于它们的散射特性。 多孔颗粒具有更广泛的颗粒尺寸范围，并且由于尘埃自散射而产生高线性偏振，允许毫米到厘米大小的颗粒来解释偏振观测结果。 采用贝叶斯方法，我们利用多孔颗粒拟合了阿塔卡马大型毫米/亚毫米阵列 (ALMA) 和甚大天线阵 (VLA) 对 HL Tau 星盘的多波长连续谱和毫米波偏振观测数据。 从 1 毫米到 1 米的适度多孔颗粒可以解释连续谱和偏振观测结果，特别是在 20 到 60 天文单位之间的区域。 如果 HL Tau 中的颗粒是多孔的，则根据当前的偏振观测结果，其孔隙率应在 70% 到 97% 之间。 我们还预测，未来对更长波长（例如 ALMA B1 和下一代甚大天线阵 ngVLA）的自散射线性偏振观测可能进一步限制颗粒的孔隙率和大小。 显示英文摘要

摘要： Dust particle sizes constrained from dust continuum and polarization observations by radio interferometry are inconsistent by at least an order of magnitude. Motivated by porous dust observed in small Solar System bodies (e.g., from the Rosetta mission), we explore how the dust particle's porosity affects the estimated particle sizes from these two methods. Porous particles have lower refractive indices, which affect both opacity and polarization fraction. With weaker Mie interference patterns, the porous particles have lower opacity at mm wavelengths than the compact particles if the particle size exceeds several hundred microns. Consequently, the inferred dust mass using porous particles can be up to a factor of six higher. The most significant difference between compact and porous particles is their scattering properties. The porous particles have a wider range of particle sizes with high linear polarization from dust self-scattering, allowing mm-cm-sized particles to explain polarization observations. With a Bayesian approach, we use porous particles to fit HL Tau disk's multi-wavelength continuum and mm-polarization observations from ALMA and VLA. The moderately porous particles with sizes from 1 mm-1 m can explain both continuum and polarization observations, especially in the region between 20-60 au. If the particles in HL Tau are porous, the porosity should be from 70% to 97% from current polarization observations. We also predict that future observations of the self-scattering linear polarization at longer wavelengths (e.g., ALMA B1 and ngVLA) have the potential to further constrain the particle's porosity and size.