Molecules with ALMA at Planet-forming Scales (MAPS). I. Program Overview and Highlights
Molecules with ALMA at Planet-forming Scales (MAPS). I. Program Overview and Highlights
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DOI：
10.3847/1538-4365/ac1432
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
K. Öberg;V. Guzmán;C. Walsh;Y. Aikawa;E. Bergin;C. Law;R. Loomis;Felipe Alarcón;S. Andrews
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文献类型：
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作者：
K. Öberg;V. Guzmán;C. Walsh;Y. Aikawa;E. Bergin;C. Law;R. Loomis;Felipe Alarcón;S. Andrews
行星在年轻恒星周围富含尘埃和气体的盘中形成并获得其成分，这一过程的结果与盘的化学性质密切相关。分子在盘上的分布调节行星的元素组成，包括C/N/O/S比和金属度（O/H和C/H），以及水和生物前相关有机物的获取。来自分子的辐射也编码了关于盘电离水平、温度结构、运动学和气体表面密度的信息，这些都是盘演化和行星形成模型的关键成分。行星形成尺度下的分子与阿尔马（MAPS）阿尔马大型计划旨在通过探索低至10 Au尺度的盘化学结构来扩展我们对行星形成化学的理解。MAPS计划的重点是五个磁盘-IM Lup，GM Aur，AS 209，HD 163296和MWC 480-其中尘埃子结构被检测到，行星形成似乎正在进行中。我们在四个光谱设置中观察到这些圆盘，它们共同覆盖了来自20多个不同物种的150条谱线。本文介绍了天体物理学杂志增刊的MAPS特刊，概述了计划的动机，磁盘样本，观测细节和校准策略。我们还强调了关键的结果，包括发现灰尘，气体和化学亚结构之间的联系，大水库的腈和其他有机物的内部磁盘区域，并提高了大多数磁盘的C/O比。我们将讨论这些结果是如何重塑我们对行星形成化学的看法的。
Planets form and obtain their compositions in dust- and gas-rich disks around young stars, and the outcome of this process is intimately linked to the disk chemical properties. The distributions of molecules across disks regulate the elemental compositions of planets, including C/N/O/S ratios and metallicity (O/H and C/H), as well as access to water and prebiotically relevant organics. Emission from molecules also encodes information on disk ionization levels, temperature structures, kinematics, and gas surface densities, which are all key ingredients of disk evolution and planet formation models. The Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program was designed to expand our understanding of the chemistry of planet formation by exploring disk chemical structures down to 10 au scales. The MAPS program focuses on five disks—around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480—in which dust substructures are detected and planet formation appears to be ongoing. We observed these disks in four spectral setups, which together cover ∼50 lines from over 20 different species. This paper introduces the Astrophysical Journal Supplement’s MAPS Special Issue by presenting an overview of the program motivation, disk sample, observational details, and calibration strategy. We also highlight key results, including discoveries of links between dust, gas, and chemical substructures, large reservoirs of nitriles and other organics in the inner disk regions, and elevated C/O ratios across most disks. We discuss how this collection of results is reshaping our view of the chemistry of planet formation.