标题： 行星状星云的起源与形态：检验双星假说 显示英文标题

标题： The Origin and Shaping of Planetary Nebulae: Putting the Binary Hypothesis to the Test

摘要： 行星状星云（PNe）是在渐近巨星支（AGB）阶段的恒星经历强烈的质量损失期时抛射出的包层气体。 这些星云具有令人惊叹的各种形状，其中大多数是非球对称的。 围绕是什么以及什么因素塑造了这些演化中的中间质量恒星的包层气体的争论已经持续了二十年。 如今，科学界逐渐达成共识，即单颗恒星无法轻易地制造出行星状星云并赋予它们非球对称的形状，而二元伴星，甚至可能是亚恒星质量的伴星，在大多数情况下可能是必需的。 然而，这一理论假设尚未通过观测得到验证。 在这篇综述中，我们将从理论和观测两个角度讨论这个问题，阐明阻碍清晰观测测试的障碍以及改善现状的方法。 我们还讨论了该假设的间接检验及其对恒星天文学和星系天文学的意义。 显示英文摘要

摘要： Planetary nebulae (PNe) are circumstellar gas ejected during an intense mass-losing phase in the the lives of asymptotic giant branch stars. PNe have a stunning variety of shapes, most of which are not spherically symmetric. The debate over what makes and shapes the circumstellar gas of these evolved, intermediate mass stars has raged for two decades. Today the community is reaching a consensus that single stars cannot trivially manufacture PNe and impart to them non spherical shapes and that a binary companion, possibly even a sub-stellar one, might be needed in a majority of cases. This theoretical conjecture has however not been tested observationally. In this review we discuss the problem both from the theoretical and observational standpoints, explaining the obstacles that stand in the way of a clean observational test and ways to ameliorate the situation. We also discuss indirect tests of this hypothesis and its implications for stellar and galactic astrophysics.