Sanemichi Z. Takahashi^1,2 and Takayuki Muto³
Astrophysical Journal 865, 102 Link to Article [DOI: 10.3847/1538-4357/aadda0]
¹Department of Applied Physics, Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677, Japan
²National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
³Division of Liberal Arts, Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677, Japan

Structure formation in young protoplanetary disks is investigated using a one-dimensional model including the formation and the evolution of disks. Recent observations with ALMA found that a ring–hole structure may be formed in young protoplanetary disks, even when the disk is embedded in the envelope. We present a one-dimensional model for the formation of a protoplanetary disk from a molecular cloud core and its subsequent long-term evolution within a single framework. Such long-term evolution has not been explored by numerical simulations due to the limitations of computational power. In our model, we calculate the time evolution of the surface density of the gas and dust with the wind mass loss and the radial drift of the dust in the disk. We find that the MHD disk wind is a viable mechanism for the formation of a ring–hole structure in young disks. We perform a parameter study of our model and derive conditions for the formation of ring–hole structures within 6 × 10⁵ yr after the start of the collapse of the molecular cloud core. The final outcome of the disk shows five types of morphology; this can be understood by comparing the timescales of the viscous diffusion, the mass loss by MHD disk wind, and the radial drift of the dust. We discuss the implication of the model for the WL 17 system, which is suspected to be an embedded, yet transitional, disk.

¹Yu.Shkuratov, ¹Ye.Surkov, ²M.Ivanov, ¹V.Korokhin, ¹V.Kaydash, ³G.Videen, ⁴C.Pieters, ¹D.Stankevich
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2018.11.002]
¹V.N. Karazin Kharkiv National University, 35 Sumska St, Kharkiv, 61022, Ukraine
²V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 19, Kosygin st., 119991 Moscow, Russia
³Space Science Institute, 4750 Walnut St. Suite 205, Boulder CO 80301, USA
⁴Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA
Copyright Elsevier

We provide and test a method to obtain significant improvement of available Chandrayaan-1 M³ data. The advance is achieved using the Gaussian λ-convolution of spectra and Fourier filtration of images. The main result is imagery of the reflectance across different wavelengths as well as parameters of 1 μm and 2 μm absorption bands with unprecedented quality. This approach can be particularly useful for further investigations using M³ data, since it produces improved imagery of various lunar surface characteristics. We studied a region comprising a portion of the Aristarchus Plateau, Montes Agricola, and a small part of the mare surface in Ocean Procellarum to the north of Montes Agricola. We found that the lava flows in the area between the Aristarchus Plateau and Montes Agricola have a chemical/mineral composition different in comparison with mare areas to the northwest of the ridge Montes Agricola. We also identified distinct spectral properties of morphologically young craters located on the plateau and mare surface. A correlation diagram for positions of the minima of the 1 μm and 2 μm bands allows a cluster analysis of the region, and we map areas associated with a cluster corresponding to pyroclastic glasses. Relationships between geologic and spectral parameter maps were established.

¹Speelmanns, I.M., ¹Schmidt, M.W., ¹Liebske, C.
Geophysical Research Letters 45, 7434-7443 Link to Article [DOI: 10.1029/2018GL079130]
¹ETH Zurich, Department of Earth Sciences, Zurich ZH,, Switzerland

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