From Nature, 12 January 2022
Star formation near the Sun is driven by expansion of the Local Bubble
太阳附近的恒星形成是由局部气泡的扩张驱动的
Catherine Zucker1,2 ✉, Alyssa A. Goodman1, João Alves3, Shmuel Bialy1,4, Michael Foley1,
Joshua S. Speagle5,6,7, Josefa Groβschedl3, Douglas P. Finkbeiner1,8, Andreas Burkert9,10,
Diana Khimey1 & Cameren Swiggum3,11
For decades we have known that the Sun lies within the Local Bubble, a cavity of low-density, high-temperature plasma surrounded by a shell of cold, neutral gas and dust. However, the precise shape and extent of this shell, the impetus and timescale for its formation, and its relationship to nearby star formation have remained uncertain, largely due to low-resolution models of the local interstellar medium. Here we report an analysis of the three-dimensional positions, shapes and motions of dense gas and young stars within 200 pc of the Sun, using new spatial and dynamical constraints. We find that nearly all of the star-forming complexes in the solar vicinity lie on the surface of the Local Bubble and that their young stars show outward expansion mainly perpendicular to the bubble’s surface. Tracebacks of these young stars’ motions support a picture in which the origin of the Local Bubble was a burst of stellar birth and then death (supernovae) taking place near the bubble’s centre beginning approximately 14 Myr ago. The expansion of the Local Bubble created by the supernovae swept up the ambient interstellar medium into an extended shell that has now fragmented and collapsed into the most prominent nearby molecular clouds, in turn providing robust observational support for the theory of supernova-driven star formation.
几十年来，我们已经知道太阳位于局部气泡内，局部气泡是一个低密度、高温等离子体的腔体，被一层冷的、中性的气体和尘埃所包围。然而，这个壳层的精确形状和范围，它形成的动力和时间尺度，以及它与附近恒星形成的关系仍然不确定，这主要是由于当地星际介质的低分辨率模型。在本文中，我们利用新的空间和动力学约束，分析了距离太阳200秒差距内致密气体和年轻恒星的三维位置、形状和运动。我们发现，太阳附近几乎所有的恒星形成复合物都位于局部气泡的表面，它们的年轻恒星主要向外扩张，垂直于气泡的表面。对这些年轻恒星运动的追溯支持了这样一种说法，即本地气泡的起源是大约14密尔以前发生在气泡中心附近的恒星诞生和死亡(超新星)的爆发。由超新星产生的局部气泡的膨胀将周围的星际介质扫进了一个扩展的外壳，现在这个外壳已经破碎并坍缩成附近最显著的分子云，反过来为超新星驱动的恒星形成理论提供了有力的观测支持。
逐句对照
For decades we have known that the Sun lies within the Local Bubble, a cavity of low-density, high-temperature plasma surrounded by a shell of cold, neutral gas and dust.
几十年来，我们已经知道太阳位于局部气泡内，局部气泡是一个低密度、高温等离子体的腔体，被一层冷的、中性的气体和尘埃所包围。
| cavity n. a hole or empty space inside sth solid 洞；孔；窟窿；腔 plasma 等离子体 neutral 中性的 |
However, the precise shape and extent of this shell, the impetus and timescale for its formation, and its relationship to nearby star formation have remained uncertain, largely due to low-resolution models of the local interstellar medium.
然而，这个壳层的精确形状和范围，它形成的动力和时间尺度，以及它与附近恒星形成的关系仍然不确定，这主要是由于当地星际介质的低分辨率模型。
| impetus : the force or energy with which sth moves 动量；动力；惯性 interstellar adj. between the stars in the sky 星际的 |
Here we report an analysis of the three-dimensional positions, shapes and motions of dense gas and young stars within 200 pc of the Sun, using new spatial and dynamical constraints.
在本文中，我们利用新的空间和动力学约束，分析了距离太阳200秒差距内致密气体和年轻恒星的三维位置、形状和运动。
| pc: parsec 秒差距(3.26光年) a unit of measure for interstellar space that is equal to 3.26 light-years. |
We find that nearly all of the star-forming complexes in the solar vicinity lie on the surface of the Local Bubble and that their young stars show outward expansion mainly perpendicular to the bubble’s surface.
我们发现，太阳附近几乎所有的恒星形成复合物都位于局部气泡的表面，它们的年轻恒星主要向外扩张，垂直于气泡的表面。
| vicinity : a surrounding or nearby region 附近 perpendicular adj. 垂直的 |
Tracebacks of these young stars’ motions support a picture in which the origin of the Local Bubble was a burst of stellar birth and then death (supernovae) taking place near the bubble’s centre beginning approximately 14 Myr ago.
对这些年轻恒星运动的追溯支持了这样一种说法，即本地气泡的起源是大约1400万年以前发生在气泡中心附近的恒星诞生和死亡(超新星)的爆发。
| supernovae 超新星 |
超新星爆炸