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Full-Text Articles in Physical Sciences and Mathematics

Rotational Quenching Of Hd Induced By Collisions With H2 Molecules, Yier Wan, Nadulvalath Balakrishnan, B. H. Yang, R. C. Forrey, P. C. Stancil Jun 2019

Rotational Quenching Of Hd Induced By Collisions With H2 Molecules, Yier Wan, Nadulvalath Balakrishnan, B. H. Yang, R. C. Forrey, P. C. Stancil

Chemistry and Biochemistry Faculty Research

Rate coefficients for rotational transitions in HD induced by H2 impact for rotational levels of HD j ≤ 8 and temperatures 10 K ≤ T ≤ 5000 K are reported. The quantum mechanical close-coupling (CC) method and the coupled-states (CS) decoupling approximation are used to obtain the cross-sections employing the most recent highly accurate H2–H2 potential energy surface (PES). Our results are in good agreement with previous calculations for low-lying rotational transitions The cooling efficiency of HD compared with H2 and astrophysical applications are briefly discussed.


One Solution To The Mass Budget Problem For Planet Formation: Optically Thick Disks With Dust Scattering, Zhaohuan Zhu, Shangjia Zhang, Yan-Fei Jiang, Akimasa Kataoka, Tilman Birnstiel, Cornelis P. Dullemond, Sean M. Andrews, Jane Huang, Laura M. Perez, John M. Carpenter, Xue-Ning Bai, David J. Wilner, Luca Ricci May 2019

One Solution To The Mass Budget Problem For Planet Formation: Optically Thick Disks With Dust Scattering, Zhaohuan Zhu, Shangjia Zhang, Yan-Fei Jiang, Akimasa Kataoka, Tilman Birnstiel, Cornelis P. Dullemond, Sean M. Andrews, Jane Huang, Laura M. Perez, John M. Carpenter, Xue-Ning Bai, David J. Wilner, Luca Ricci

Physics & Astronomy Faculty Research

Atacama Large Millimeter Array (ALMA) surveys have suggested that the dust in Class II disks may not be enough to explain the averaged solid mass in exoplanets, under the assumption that the mm disk continuum emission is optically thin. This optically thin assumption seems to be supported by recent Disk Substructures at High Angular Resolution Project (DSHARP) observations where the measured optical depths are mostly less than one. However, we point out that dust scattering can considerably reduce the emission from an optically thick region. If that scattering is ignored, an optically thick disk with scattering can be misidentified as …