论文标题
外部太阳系星云的寿命来自碳质软管
Lifetime of the Outer Solar System Nebula From Carbonaceous Chondrites
论文作者
论文摘要
原星盘（PPD）的演变和寿命在行星系统的形成和结构中起着核心作用。天文观测表明，PPD在两个时标的进化，在恒星上累积了多达数百万年（MYR），然后在<1 Myr <1 Myr内进行气体散发。由于太阳星云磁场是由原球磁盘的气体维持的，因此我们可以使用古磁测量来推断太阳星云的寿命。在这里，我们使用对陨石的古磁测量来限制这一生命周期，并研究太阳星云是否具有两种时限的演化。我们报告了两种碳质软管的整体样本的古磁测量：Allan Hills A77307和Dominion范围08006。形成钙铝富含钙的夹杂物后的MYR。再加上先前的古磁研究，我们得出结论，在1-3 AU区域耗散星云后，太阳星云的耗散发生在<1.5 Myr，这表明原始磁盘在其生命的两次频率演化中都通过插入式和/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或或/或或或或或或一定程度地逐渐消失。我们还讨论了使用散装软件获得太阳星云场的稳健记录所需的未来方向，包括从陨石中获取年龄和实验工作，以确定磁铁矿如何在软骨母体身体变化过程中获得磁化。
The evolution and lifetime of protoplanetary disks (PPDs) play a central role in the formation and architecture of planetary systems. Astronomical observations suggest that PPDs evolve in two timescales, accreting onto the star for up to several million years (Myr) followed by gas dissipation within <1 Myr. Because solar nebula magnetic fields are sustained by the gas of the protoplanetary disk, we can use paleomagnetic measurements to infer the lifetime of the solar nebula. Here, we use paleomagnetic measurements of meteorites to constrain this lifetime and investigate whether the solar nebula had a two-timescale evolution. We report on paleomagnetic measurements of bulk subsamples of two CO carbonaceous chondrites: Allan Hills A77307 and Dominion Range 08006. If magnetite in these meteorites can acquire a crystallization remanent magnetization that recorded the ambient field during aqueous alteration, our measurements suggest that the local magnetic field strength at the CO parent body location was <0.9 \muT at some time between 2.7 and 5.1 Myr after the formation of calcium-aluminum-rich inclusions. Coupled with previous paleomagnetic studies, we conclude that the dissipation of the solar nebula in the 3-7 AU region occurred <1.5 Myr after the dissipation of the nebula in the 1-3 AU region, suggesting that protoplanetary disks go through a two-timescale evolution in their lifetime, consistent with dissipation by photoevaporation and/or magnetohydrodynamic winds. We also discuss future directions necessary to obtain robust records of solar nebula fields using bulk chondrites, including obtaining ages from meteorites and experimental work to determine how magnetite acquires magnetization during chondrite parent body alteration.
