AI 中文总结
研究系外小行星带中的水汽盘，改编扩展模型跟踪其脱气等过程，通过模拟探索参数空间，发现太阳质量及以上恒星的系统产水汽高效，内行星能大量吸水，当前设备有望探测到此类水汽盘。
AI 中文摘要
对数十个与冷系外柯伊伯带相关的次级一氧化碳气体盘的观测及其他论据，使克拉尔等人（2024年）提出水冰也可能在系外小行星带升华，这为包括地球在内的类地行星的水输送提供了新途径。我们旨在对这种水汽盘进行建模，并描述其在一系列不同宿主恒星的太阳系中的物理特性。我们进一步研究这些系统内部区域潜在行星吸收这种水的影响。我们改编并扩展了克拉尔等人（2024年）的模型，以跟踪水汽盘的脱气、光解离和粘性演化。我们进行了一系列模拟来探索参数空间，重点关注恒星质量、母带质量及其轨道位置。我们还纳入了一颗内行星，以估计作为盘特性和系统结构函数的水吸收质量。我们发现，拥有太阳质量（及更高）恒星的系统能非常高效地产生水汽，使带中几乎所有初始存在的冰升华。在大多数情况下，大部分气体质量在恒星光度最高时早期产生。内行星吸收的水量可接近带的初始冰质量，导致行星的水储量与地球相当或超过地球，可能形成海洋行星。我们发现，在包含系外小行星带的系统中，原行星盘消散后不久就会发生水脱气。即使在相对低质量的水盘中，阿塔卡马大型毫米/亚毫米波阵列（ALMA）、詹姆斯·韦布空间望远镜（JWST）和极大望远镜（ELT）也能够在数千万年内探测到这种水汽。因此，如果存在这种水汽盘，用当前设备应该可以探测到。
英文摘要
Observations of tens of secondary CO gas discs associated with cold exo-Kuiper belts together with other arguments have led Kral et al (2024) to propose that water ice could also sublimate in exo-asteroid belts, suggesting a new pathway for the delivery of water to terrestrial planets, including Earth. We aim to model such water vapour discs and to characterise their physical properties across a range of extrasolar systems with different host stars. We further investigate the implications for the accretion of this water by potential planets located in the inner regions of these systems. We adapt and extend the model of Kral et al (2024) to follow the outgassing, photodissociation, and viscous evolution of water vapour discs. We perform a suite of simulations exploring the parameter space, focusing on the stellar mass, the mass of the parent belt, and its orbital location. We additionally include an inner planet to estimate the mass of water accreted as a function of disc properties and system architecture. We find that systems hosting Sun's mass (and higher) stars produce water vapour very efficiently, sublimating nearly all of the ice initially present in the belt. In most cases, the bulk of the gas mass is generated early, when the stellar luminosity is highest. The amount of water accreted by inner planets can approach the initial ice mass of the belt, leading to planets with water inventories comparable to or exceeding those of Earth, potentially creating ocean planets. We find that water outgassing occurs early after the protoplanetary disc dissipates in systems containing exo-asteroid belts. ALMA, JWST and ELT are capable of detecting this water vapour for several tens of millions of years, even in relatively low-mass water discs. Hence, if such water gas discs are present, they should be detectable with current facilities.
Comments18 pages, 20 figures
