Millimeter gap contrast as a probe for turbulence level in protoplanetary disks

查看全文 作　　者：Yao [1,2]Liu;Gesa H.-[3]M.Bertrang;Mario [3]Flock;Giovanni [4,5]P.Rosotti;Ewine F.van [1]Dishoeck;Yann [6]Boehler;Stefano [7]Facchini;Can [8]Cui;Sebastian [9]Wolf;Min [2]Fang 机构地区：[1]Max-Planck-Institut für Extraterrestrische Physik,Garching,85748,Germany;[2]Purple Mountain Observatory&Key Laboratory for Radio Astronomy,Chinese Academy of Sciences,Nanjing,210023,China;[3]Max-Planck-Institut für Astronomie,Heidelberg,D-69117,Germany;[4]Leiden Observatory,Leiden University,Leiden,NL-2300,the Netherlands;[5]School of Physics and Astronomy,University of Leicester,Leicester,LE17RH,UK;[6]UniversitéGrenoble Alpes,French National Centre for Scientific Research,Institute for Planetary Sciences and Astrophysics,Grenoble,Grenoble,F-38000,France;[7]European Southern Observatory,Garching,85748,Germany;[8]Department of Applied Mathematics and Theoretical Physics,University of Cambridge,Centre for Mathematical Sciences,Cambridge,CB3 OWA,UK;[9]Institut für Theoretische Physik und Astrophysik,Christian-Albrechts-Universität zu kiel,Kiel,24118,Germany 出　　处：《Science China(Physics,Mechanics & Astronomy)》索引2022年第65卷第12期,共14页 基　　金：supported by the National Natural Science Foundation of China(Grant No.11973090);the Science Research Grants from the China Manned Space Project(Grant No.CMS-CSST-2021-B06);supported by the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Program(Grant No.757957);supported by the Netherlands Organisation for Scientific Research(Grant No.016.Veni.192.233);STFC Ernest Rutherford Fellowship(Grant No.ST/T003855/1)。 摘　　要：Turbulent motions are believed to regulate angular momentum transport and influence dust evolution in protoplanetary disks.Measuring the strength of turbulence is challenging through gas line observations because of the requirement for high spatial and spectral resolution data,and an exquisite determination of the temperature.In this work,taking the well-known HD 163296 disk as an example,we investigated the contrast of gaps identified in high angular resolution continuum images as a probe for the level of turbulence.With self-consistent radiative transfer models,we simultaneously analyzed the radial brightness profiles along the disk major and minor axes,and the azimuthal brightness profiles of the B67 and B100 rings.By fitting all the gap contrasts measured from these profiles,we constrained the gas-to-dust scale height ratioΛto be 3.0^(+0.3)_(−0.8),1.2^(+0.1)_(−0.1),and≥6.5 for the D48,B67,and B100 regions,respectively.The varying gas-to-dust scale height ratios indicate that the degree of dust settling changes with radius.The inferred values forΛtranslate into a turbulence level of α_(turb)<3×10^(−3) in the D48 and B100 regions,which is consistent with previous upper limits set by gas line observations.However,turbulent motions in the B67 ring are strong with α_(turb)∼1.2×10^(−2).Due to the degeneracy betweenΛand the depth of dust surface density drops,the turbulence strength in the D86 gap region is not constrained. 关 键 词：protoplanetary disks radiative transfer planet formation