accepted for publication by A&A on 2019.02.25, 6 figures, 11 tables, ancillary data contains the full reaction tables and a full PDF version of the final manuscript as accepted for publication
The elemental depletion of interstellar sulfur from the gas phase has been a recurring challenge for astrochemical models. Observations show that sulfur remains relatively non-depleted with respect to its cosmic value throughout the diffuse and translucent stages of an interstellar molecular cloud, but its gas-phase constituents cannot account for this cosmic value towards higher-density environments. We have attempted to address this issue by modeling the evolution of an interstellar cloud from its pristine state as a diffuse atomic cloud to a molecular environment of much higher density, using a gas/grain astrochem. code and an enhanced sulfur reaction network. A common gas/grain reaction network has been systematically updated and greatly extended based on previous lit. and models, with a focus on the grain chemistry and processes. A simple model was used to benchmark the resulting network updates, and the results of the model were compared to typical astronomical observations sourced from the literature. Our new gas/grain model is able to reproduce the elemental depletion of sulfur, whereby sulfur can be depleted from the gas-phase by two orders of magnitude, and this process may occur under dark cloud conditions if the cloud has a chemical age of at least 1 Myrs. The resulting mix of sulfur-bearing species on the grain ranges across all the most common chemical elements (H/C/N/O), not dissimilar to the molecules observed in cometary environments. Notably, this mixture is not dominated simply by H2S, unlike all other current astrochem. models. Despite our relatively simple physical model, most of the known gas-phase S-bearing molecular abundances are accurately reproduced under dense conditions, however they are not expected to be the primary molecular sinks of sulfur. Our model predicts that most of the missing sulfur is in the form of organo-sulfur species trapped on grains.
Thermally irreversible sulfur chemisorption on silicate grains as a major sulfur reservoir in molecular clouds
Institute of Low Temperature Science, Hokkaido University（北海道大学低温科学研究所）；Department of Chemistry, Hiroshima University（广岛大学化学系）；Departamento de Astrofísica Molecular, Instituto de Física Fundamental, CSIC（西班牙国家研究委员会基础物理研究所分子天体物理学部）；RIKEN Pioneering Research Institute（理研先锋研究机构）
A quest for sulfur-bearing refractory species. Identification of CaS in the interstellar medium
Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙国家研究委员会-国家航空航天技术研究所）；Institut de Ciències de l’Espai (ICE), CSIC（空间科学研究所（ICE），西班牙国家研究委员会）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究学院（IEEC））；Department of Astronomy, University of Florida（佛罗里达大学天文学系）；I. Physikalisches Institut, Universität zu Köln（科隆大学第一物理研究所）；Observatorio Astronómico Nacional (OAN)（国家天文台（OAN））
Formation of thiocarbonic acid (H$_2$CS$_3$) -- the sulfur counterpart of carbonic acid (H$_2$CO$_3$) - in interstellar analog ices
W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa（夏威夷大学马诺阿分校 W.M. 凯克天体化学研究实验室）；Department of Chemistry, University of Hawaii at Manoa（夏威夷大学马诺阿分校化学系）；Department of Chemistry & Biochemistry, University of Mississippi（密西西比大学化学与生物化学系）；Université Paris-Saclay（巴黎萨克雷大学）
Where Have All the Sulfur Atoms Gone? Polycyclic Aromatic Hydrocarbon as a Possible Sink for the Missing Sulfur in the Interstellar Medium. I. The C--S Band Strengths
A detection of sulfur-bearing cyclic hydrocarbons in space
Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理研究所）；Centro de Astrobiología (CAB), CSIC-INTA（西班牙国家航空航天技术研究所/西班牙高等科学研究理事会天体生物学中心）；RIKEN（理化学研究所）
Water enhances the formation of refractory sulfur in interstellar ices
Centro de Astrobiología (CAB), INTA-CSIC（西班牙国家航空航天技术研究所-西班牙国家科学研究委员会天体生物学中心）；Departamento de Física de la Tierra y Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid（马德里康普顿斯大学物理科学学院地球与天体物理学系）；Instituto de Química Física Blas Cabrera (CSIC)（西班牙国家科学研究委员会布拉斯·卡布雷拉物理化学研究所）；Department of Physics, National Central University（中原大学物理系）
Abundances of planetary nebulae and evolved stars: Iron and sulfur depletion, and carbon and nitrogen enrichment, in low- and intermediate-mass stellar populations in the Milky Way
METAL: The Metal Evolution, Transport, and Abundance in the Large Magellanic Cloud Hubble program. III. Interstellar Depletions, Dust-to-Metal, and Dust-to-Gas Ratios Versus Metallicity
Reaction Mechanisms and Kinetics of CN and CCH with H2CS: Implications for Interstellar Sulfur Chemistry
De Vinci Higher Education, De Vinci Research Center（德文奇高等教育中心，德文奇研究中心）；Institut Supérieur des Arts Multimédia de la Manouba, Université de la Manouba（马努巴多媒体艺术学院，马努巴大学）；Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Condensée, Université Tunis El Manar（突尼斯理学院，凝聚态物质物理实验室，突尼斯埃尔曼纳尔大学）；Observatoire de Paris, Université PSL, CNRS-UMR 8112, LUX（巴黎天文台，巴黎文理研究大学，法国国家科学研究中心联合研究单位8112，LUX）；Department of Physics, College of Khurma University, Taif University（物理系，库尔玛学院，塔伊夫大学）
The physical and chemical structure of TMC-1. The spatial distribution and excitation conditions of carbon, oxygen, and sulfur bearing species: Depletion of CO and CS
Instituto de Física Fundamental (IFF-CSIC)（基础物理研究所）；Observatorio Astronómico Nacional (IGN)（国家天文台）；Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN)（耶贝斯天文台技术开发中心）
METAL: The Metal Evolution, Transport, and Abundance in the Large Magellanic Cloud Hubble program. II. Variations of interstellar depletions and dust-to-gas ratio within the LMC
Modeling the UV-photon irradiation of CS$_2$-bearing ices in the laboratory with the pyRate gas-grain astrochemical code. New insights into the missing sulfur problem
Max-Planck-Institut für Extraterrestrische Physik (MPE)（马克斯·普朗克地外物理研究所）；Centro de Astrobiología (CSIC-INTA)（天体生物学中心（西班牙国家科学技术研究委员会-国家航空航天技术研究所））
Connecting the dusty dots: dust depletion and extinction of local interstellar clouds
University of Geneva（日内瓦大学）；Wits Centre for Astrophysics, School of Physics, University of the Witwatersrand（威特沃特斯兰德大学物理学院天体物理中心）；European Southern Observatory（欧洲南方天文台）；Université Claude Bernard Lyon 1, Centre de Recherche Astrophysique de Lyon UMR5574（里昂第一大学克洛德·贝尔纳大学，里昂天体物理研究中心UMR5574）；French-Chilean Laboratory for Astronomy (FCLA), CNRS-IRL3386, U. de Chile（法智利天体物理实验室(FCLA)，CNRS-IRL3386，智利大学）；AURA for ESA, Space Telescope Science Institute（ESA支持的AURA，太空望远镜科学研究所）
Interstellar Silicon Depletion and the Ultraviolet Extinction
Spinning small silicate grains were recently invoked to account for the Galactic foreground anomalous microwave emission. These grains, if present, will absorb starlight in the far ultraviolet (UV). There is also renewed interest in attributing the enigmatic 2175 Angstrom interstellar extinction bump to small silicates. To probe the role of silicon in the UV extinction, we explore the relations between the amount of silicon required to be locked up in silicates [Si/H]_{dust} and the 2175 Angstrom bump or the far-UV extinction rise, based on an analysis of the extinction curves along 46 Galacti…
The Abundance of Boron in Diffuse Interstellar Clouds
我们提出了一个全面的调查硼丰度在弥漫的星际云的观测与空间望远镜成像光谱仪（STIS）的哈勃太空望远镜。我们的56条银河系视线的样本是对B II 1362共振线的存档STIS数据进行完整搜索的结果，每个检测都被O I 1355，Cu II 1358和Ga II 1414（可用时）以相同速度吸收的存在所证实。五个以前的测量星际B II戈达德高分辨率摄谱仪观测纳入我们的分析，产生一个合并的样本，超过四倍的视线与显着的硼检测。我们的调查也构成了第一个广泛的分析星际镓从STIS光谱和扩大以前发表的结果氧和铜。观测探测了高密度和低密度的扩散环境，使星际消耗的密度依赖效应能够在每个元素的气相丰度数据中清楚地识别出来。在硼的情况下，增加的相对贫化线的视线密度相当于0.8德克斯之间的丰度差的暖相和冷相的弥漫星际介质。在温暖的低密度气体中，硼的丰度为B/H =（2.4+/-0.6）*10^-10，这意味着相对于陨石硼的丰度，硼的丰度减少了60%。除了耗尽的影响，我们的调查揭示了具有增强的硼丰度的视线，这些硼丰度可能追踪最近产生的11 B，其产生于涉及宇宙射线或中微子的spiritual反应。未来的观测将有助于解开11B合成的两个spectrum通道的相对贡献。
Silicon, sulfur and iron in the interstellar medium: a high-resolution X-ray spectral study of GX 340+0
University of Chicago（芝加哥大学）；MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理学与空间研究所）；SRON Netherlands Institute for Space Research（荷兰空间研究所）；University of Michigan（密歇根大学）；European Space Agency (ESA), European Space Research and Technology Centre (ESTEC)（欧洲空间局（ESA）欧洲空间研究与技术中心（ESTEC））
