无星核心巴纳德68的必然未来
The Inevitable Future of the Starless Core Barnard 68
摘要：
致密的小分子云核被认为是恒星的直接祖先。巴纳德68是研究得最好的例子之一，它被认为是一个稳定的球形气核原型，被弥漫的高压环境所限制。然而，对巴纳德68径向密度结构的观测表明，巴纳德68应该是引力不稳定和坍缩的，这似乎与其推断的长寿命和稳定性不一致。我们认为，巴纳德68目前正在经历一个致命的碰撞与另一个小的核心，这将导致引力坍缩。尽管这个系统仍然处于相互作用的早期阶段，我们的数值模拟表明，未来的引力坍缩已经可以在球体的外表面密度结构中检测到，该结构模仿了引力不稳定的Bonnor-Ebert球体的轮廓。在接下来的20万年里，巴纳德68将凝聚成一颗低质量的太阳型恒星，孤立地形成，周围是弥漫的热星际气体。正如在巴纳德68的现场所见，核心合并可能在触发恒星形成和塑造分子核心质量分布以及恒星初始质量函数方面发挥重要作用。
英文摘要：
Dense, small molecular cloud cores have been identified as the direct progenitors of stars. One of the best studied examples is Barnard 68 which is considered a prototype stable, spherical gas core, confined by a diffuse high-pressure environment. Observations of its radial density structure however indicate that Barnard 68 should be gravitationally unstable and collapsing which appears to be inconsistent with its inferred long lifetime and stability. We argue that Barnard 68 is currently experiencing a fatal collision with another small core which will lead to gravitational collapse. Despite the fact that this system is still in an early phase of interaction, our numerical simulations imply that the future gravitational collapse is already detectable in the outer surface density structure of the globule which mimicks the profile of a gravitationally unstable Bonnor-Ebert sphere. Within the next 200,000 years Barnard 68 will condense into a low-mass solar-type star(s), formed in isolation, and surrounded by diffuse, hot interstellar gas. As witnessed in situ for Barnard 68, core mergers might in general play an important role in triggering star formation and shaping the molecular core mass distribution and by that also the stellar initial mass function.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
