Dust Traps and the Formation of Cavities in Transition Discs: A millimetre to sub-millimetre comparison survey
Brodie J. Norfolk, Sarah T. Maddison, Christophe Pinte, Nienke van der Marel, Richard A. Booth, Logan Francis, Jean-François Gonzalez, François Ménard, Chris M.… 展开作者
Brodie J. Norfolk, Sarah T. Maddison, Christophe Pinte, Nienke van der Marel, Richard A. Booth, Logan Francis, Jean-François Gonzalez, François Ménard, Chris M. Wright, Gerrit van der Plas, Himanshi Garg
The origin of the inner dust cavities observed in transition discs remains unknown. The segregation of dust and size of the cavity is expected to vary depending on which clearing mechanism dominates grain evolution. We present the results from the Discs Down Under program, an 8.8 mm continuum Australia Telescope Compact Array (ATCA) survey targeting 15 transition discs with large (> 20 au) cavities, and compare the resulting dust emission to Atacama Large millimetre/sub-millimetre Array (ALMA) observations. Our ATCA observations resolve the inner cavity for 8 of the 14 detected discs. We fit the visibilities and reconstruct 1D radial brightness models for 10 sources with a S/N > 5sigma. We find that, for sources with a resolved cavity in both wavebands, the 8.8 mm and sub-mm brightness distributions peak at the same radius from the star. We suggest that a similar cavity size for 8.8 mm and sub-mm dust grains is due to a dust trap induced by the presence of a companion.
Large Dust Grains and a Possible Dust Trap in the Polar Circumbinary Disc of HD 98800B
Queen Mary University of London（伦敦大学玛丽女王学院）；University of Cambridge（剑桥大学）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）；European Southern Observatory（欧洲南方天文台）；Center for Astrophysics | Harvard & Smithsonian（哈佛与史密森尼天体物理中心）；Boston University（波士顿大学）；Institute for Astrophysical Research, Boston University（波士顿大学天体物理研究所）；University Grenoble Alpes（格勒诺布尔阿尔卑斯大学）
Observational signatures of eccentric Jupiters inside gas cavities in protoplanetary discs
预测一颗年轻行星如何塑造其母行星盘的气体和尘埃排放是限制原行星盘观测中不可见行星存在的关键。我们调查的情况下，2木星质量的行星，成为偏心后，迁移到一个低密度的气体空腔在其母盘。进行二维流体动力学模拟，并通过三维辐射转移计算进行后处理。在我们的圆盘模型中，行星偏心率达到~0.25，这导致空腔内气体密度的强烈不对称。这些不对称性通过光解离而增强，并且在12 CO J=3-2积分强度图中形成大尺度不对称性。它们被证明是可检测的角分辨率和噪声水平类似的ALMA观测中实现的。此外，行星的偏心率使空腔内的气体偏心，这表现为12 CO J=3-2的速度图中的等速度线变窄，拉伸和扭曲。然而，行星的偏心率并没有引起可检测的签名，在13 CO和C18 O J=3-2内的腔，因为低柱密度。在腔外，气体保持近圆形轨道，垂直延伸的光学厚CO发射在圆盘倾角> 30度的积分强度图中显示出四瓣图案。在我们的模型中，空腔内缺乏大小尘埃，这进一步意味着当行星在空腔内偏心或仍然是圆形时，亚毫米连续辐射的合成图像和近红外偏振散射光的合成图像不会显示出显着差异。
