Molecules with ALMA at Planet-forming Scales (MAPS) XII: Inferring the C/O and S/H ratios in Protoplanetary Disks with Sulfur Molecules
Romane Le Gal, Karin I. Öberg, Richard Teague, Ryan A. Loomis, Charles J. Law, Catherine Walsh, Edwin A. Bergin, Francois Menard, David J. Wilner, Sean M. Andre… 展开作者
Romane Le Gal, Karin I. Öberg, Richard Teague, Ryan A. Loomis, Charles J. Law, Catherine Walsh, Edwin A. Bergin, Francois Menard, David J. Wilner, Sean M. Andrews, Yuri Aikawa, Alice S. Booth, Gianni Cataldi, Jennifer B. Bergner, Arthur D. Bosman, L. Ilsedore Cleeves, Ian Czekala, Kenji Furuya, Viviana V. Guzmán, Jane Huang, John D. Ilee, Hideko Nomura, Chunhua Qi, Kamber R. Schwarz, Takashi Tsukagoshi, Yoshihide Yamato, Ke Zhang
备注：
Accepted for publication in The Astrophysical Journal Supplement (27 pages, 13 figures, 5 tables)
Sulfur-bearing molecules play an important role in prebiotic chemistry and planet habitability. They are also proposed probes of chemical ages, elemental C/O ratio, and grain chemistry processing. Commonly detected in diverse astrophysical objects, including the Solar System, their distribution and chemistry remain, however, largely unknown in planet-forming disks. We present CS ($2-1$) observations at $\sim0."3$ resolution performed within the ALMA-MAPS Large Program toward the five disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. CS is detected in all five disks, displaying a variety of radial intensity profiles and spatial distributions across the sample, including intriguing apparent azimuthal asymmetries. Transitions of C$_2$S and SO were also serendipitously covered but only upper limits are found. For MWC 480, we present complementary ALMA observations at $\sim0."5$, of CS, $^{13}$CS, C$^{34}$S, H$_2$CS, OCS, and SO$_2$. We find a column density ratio N(H$_{2}$CS)/N(CS)$\sim2/3$, suggesting that a substantial part of the sulfur reservoir in disks is in organic form (i.e., C$_x$H$_y$S$_z$). Using astrochemical disk modeling tuned to MWC 480, we demonstrate that $N$(CS)/$N$(SO) is a promising probe for the elemental C/O ratio. The comparison with the observations provides a super-solar C/O. We also find a depleted gas-phase S/H ratio, suggesting either that part of the sulfur reservoir is locked in solid phase or that it remains in an unidentified gas-phase reservoir. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.
Unveiling the Chemical Complexity and C/O Ratio of the HD 163296 Protoplanetary Disk: Constraints from Multi-line ALMA Observations of Organics, Nitriles, Sulfur-bearing, and Deuterated Molecules
Ammonium salt formation and abundance in protoplanetary disks
Université Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255（波尔多大学）；Carl Sagan Center, SETI Institute（卡尔·萨根中心，SETI研究所）；NASA Ames Research Center（NASA艾姆斯研究中心）
PRODIGE -- envelope to disk with NOEMA VIII. Sulfur oxides trace a shock caused by a streamer in the inner envelope of a protostar
European Southern Observatory（欧洲南方天文台）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理研究所）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Department of Physics and Astronomy, University of Rochester（罗切斯特大学物理与天文系）；Taiwan Astronomical Research Alliance (TARA)（台湾天文研究联盟）；Institute of Astronomy and Astrophysics, Academia Sinica（中央研究院天文及天文物理学研究所）；Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文研究所）；IPAG, Université Grenoble Alpes, CNRS（格勒诺布尔阿尔卑斯大学CNRS IPAG实验室）
Inventories of Rich Carbon-Chain Chemistry in Prestellar and Starless Cores in the Perseus Molecular Cloud
University of California, Berkeley（加州大学伯克利分校）；National Radio Astronomy Observatory（美国国家射电天文台）；RIKEN Cluster for Pioneering Research（理化学研究所先导研究集群）；Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心，西班牙科学研究中心-国家航空航天技术研究所）
