Secondary gas in debris discs released following the decay of long-lived radioactive nuclides, catastrophic, or resurfacing collisions
Secondary gas in debris discs released following the decay of long-lived radioactive nuclides, catastrophic, or resurfacing collisions
复制标题
长寿命放射性核素衰变、灾难性或重铺碰撞后碎片盘中释放的二次气体
DOI：
10.1093/mnras/stad2912
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发表时间：
2023
影响因子：
4.8
通讯作者：
Bonsor A
中科院分区：
文献类型：
--
作者：
Bonsor A
围绕太阳以外的恒星运行的类柯伊伯带，最常见的是通过碰撞中产生的小尘埃的热发射来检测到的。气体（尤其是二氧化碳）的排放凸显了这些星子的彗星性质。在这里，我们提出了这些带中类彗星天体释放气体的模型，这既是由于它们的热物理演化，最显着的是长寿命放射性核素的衰变，也是由于碰撞演化，包括灾难性和温和的表面重铺碰撞。我们表明，如果非灾难性碰撞或热演化主导二氧化碳气体的释放，则气体释放速率与粉尘释放速率不成正比。在这种情况下，推断彗星的成分时必须小心。非灾难性碰撞比灾难性碰撞更早地主导天然气生产，具体取决于星子带的特性。我们强调彗星热演化的重要性，包括至关重要的长寿命放射性核素的衰变，如果存在大型（10-100公里）星子，彗星作为年轻（<50 Myr）行星系统周围二氧化碳气体的来源。
Kuiper-like belts of planetesimals orbiting stars other than the Sun are most commonly detected from the thermal emission of small dust produced in collisions. Emission from gas, most notably CO, highlights the cometary nature of these planetesimals. Here, we present models for the release of gas from comet-like bodies in these belts, both due to their thermophysical evolution, most notably the decay of long-lived radioactive nuclides, and collisional evolution, including catastrophic and gentler resurfacing collisions. We show that the rate of gas release is not proportional to the rate of dust release, if non-catastrophic collisions or thermal evolution dominate the release of CO gas. In this case, care must be taken when inferring the composition of comets. Non-catastrophic collisions dominate the gas production at earlier times than catastrophic collisions, depending on the properties of the planetesimal belt. We highlight the importance of the thermal evolution of comets, including crucially the decay of long-lived radioactive nuclides, as a source of CO gas around young (<50 Myr) planetary systems, if large (10–100 km) planetesimals are present.