Department of Astronomy, University of Texas at Austin, 2515 Speedway Stop C1400, Austin, TX 78712, USA.
Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA.
Science. 2018 Sep 7;361(6406):1016-1019. doi: 10.1126/science.aap8900.
Galaxies grow inefficiently, with only a small percentage of the available gas converted into stars each free-fall time. Feedback processes, such as outflowing winds driven by radiation pressure, supernovae, or supermassive black hole accretion, can act to halt star formation if they heat or expel the gas supply. We report a molecular outflow launched from a dust-rich star-forming galaxy at redshift 5.3, 1 billion years after the Big Bang. The outflow reaches velocities up to 800 kilometers per second relative to the galaxy, is resolved into multiple clumps, and carries mass at a rate within a factor of 2 of the star formation rate. Our results show that molecular outflows can remove a large fraction of the gas available for star formation from galaxies at high redshift.
星系的生长效率低下，每次自由下落时只有一小部分可用气体转化为恒星。反馈过程，如由辐射压力、超新星或超大质量黑洞吸积驱动的外流，可以通过加热或驱逐气体供应来阻止恒星形成。我们报告了从红移 5.3 的富含尘埃的恒星形成星系中发射的分子外流，这是在大爆炸后 10 亿年。外流相对于星系达到了高达 800 公里/秒的速度，分解为多个团块，并以接近恒星形成率 2 倍的速率携带质量。我们的结果表明，分子外流可以从高红移星系中去除大量可用于恒星形成的气体。
