Probing Dust in the MWC 480 Disk from Millimeter to Centimeter Wavelengths
Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Astronomy, Peking University（北京大学天文学系）；European Southern Observatory（欧洲南方天文台）；Lunar and Planetary Laboratory, University of Arizona（亚利桑那大学月球与行星实验室）；Mullard Space Science Laboratory, University College London（伦敦大学学院穆拉德空间科学实验室）；Center for Astrophysics, Harvard & Smithsonian（哈佛&史密森尼天体物理中心）
Yangfan Shi, Feng Long, Enrique Macías, Gregory J. Herczeg, Paola Pinilla, Sean M. Andrews, David J. Wilner, Haochang Jiang, Ruobing Dong, Richard Teague, Ilari… 展开作者
Yangfan Shi, Feng Long, Enrique Macías, Gregory J. Herczeg, Paola Pinilla, Sean M. Andrews, David J. Wilner, Haochang Jiang, Ruobing Dong, Richard Teague, Ilaria Pascucci, Claudia Toci, Yuri Aikawa, Daniel Harsono, Yao Liu
备注：
29 pages, 18 figures, 4 tables. Accepted for publication in ApJ
我们利用深邃的高分辨率（约100毫弧秒）卡尔·G·扬斯基Very Large Array（VLA）Ka波段（9.1毫米）观测，对MWC 480周围的盘进行了研究，并通过与存档的阿塔卡马大型毫米波/亚毫米波阵列（ALMA）数据（0.87、1.17、1.33和3.0毫米）的联合分析，推断出尘埃的性质。在95天文单位处的显著尘埃环（B95）首次在9.1毫米波段被检测到，而较暗的外环在160天文单位处未被揭示。通过非参数化可见性建模，我们识别出两个新的环状特征：在所有波长范围内20-50天文单位处的平台，以及在B95环外0.87、1.17和1.33毫米波段的肩部，这与行星-盘相互作用的迹象一致。我们发现B95环的宽度在不同波长下保持不变，这表明碎片化主导径向扩散，或环内存在未解析的亚结构。解析光谱建模得到两种尘埃解，能够同样好地再现观测结果：紧凑颗粒或高度多孔（90%）颗粒，其中碳质成分分别由耐火有机物或无定形碳主导。推断的最大颗粒尺寸在两个环的位置达到峰值，并在B95环内达到厘米级。总尘埃质量为860±95_-78 M_⊕/1500±440_-330 M_⊕（内盘大/小颗粒解）和230±14_-13 M_⊕（两种尘埃混合物）。B95环单独包含100±5_-5 M_⊕和43±2_-2 M_⊕，足以组装巨行星的核心。最后，我们强调了宽带、多波段观测在确定原行星盘中尘埃组成和孔隙率方面的强大作用。
英文摘要：
We present deep, high-resolution ($\sim$100 mas) Karl G. Jansky Very Large Array (VLA) Ka-band (9.1 mm) observations of the disk around MWC 480, and infer dust properties through a combined analysis with archival Atacama Large Millimeter/submillimeter Array (ALMA) data at 0.87, 1.17, 1.33, and 3.0 mm. The prominent dust ring at 95 au (B95) is detected at 9.1 mm for the first time, while the faint outer ring at 160 au is not revealed. Through non-parametric visibility modeling, we identified two new annular features: a plateau within 20-50 au across all wavelengths, and a shoulder exterior to the B95 ring at 0.87, 1.17 and 1.33 mm, consistent with signatures of planet-disk interaction. We find that the width of the B95 ring remains constant across wavelengths, suggesting that fragmentation dominates over radial diffusion or that unresolved substructure is present within the ring. Resolved spectral modeling yields two families of dust solutions that reproduce the observations equally well: compact grains or highly porous (90\%) grains, with carbonaceous components dominated by refractory organics or amorphous carbon, respectively. The inferred maximum grain sizes peak at the locations of the two rings and reach centimeter within the B95 ring. The total dust masses are $860^{+95}_{-78}\rm~M_\oplus$/$1500^{+440}_{-330}\rm~M_\oplus$ (large/small-grain solution in inner disk) and $230^{+14}_{-13}\rm~M_\oplus$ for the two dust mixtures. The B95 ring alone contains $100^{+5}_{-5}\rm~M_\oplus$ and $43^{+2}_{-2}\rm~M_\oplus$, respectively, sufficient to assemble the cores of giant planets. Finally, we highlight the power of broadband, multi-wavelength observations in placing better constraints on dust composition and porosity in protoplanetary disks.
The MESAS Project: ALMA observations of the F-type stars $γ$ Lep, $γ$ Vir A, and $γ$ Vir B
由于缺乏大多数光谱类型的数据，在亚毫米到厘米波长范围内的恒星光谱仍然没有得到很好的限制。一个准确的表征恒星发射在这一制度是需要测试恒星大气模型，也是必不可少的揭示与未解决的星周碎片的排放。我们目前的ALMA观测的三个附近，主序星，碎片少，F-型恒星$γ$ Lep，$γ$ Vir A，和$γ$ Vir B在0.87和1.29毫米。我们使用这些数据来约束半经验大气模型。我们讨论了这些恒星的大气结构，探索潜在的短期变化，以及对碎片盘研究的潜在影响。这些结果是正在进行的活动的一部分，以获得长波长观测的碎片贫星，题为测量恒星大气层的发射在亚毫米/毫米波长（MESAS）。
