Magnetic fields, outflows and feedback in spiral galaxies

螺旋星系中的磁场、流出和反馈

• 批准号: 184201-2011
• 负责人: Irwin, Judith
• 金额: $ 3.5万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=546009
• 关键词: Magnetic; fields; outflows; feedback; spiral

Spiral galaxies are surrounded by gaseous halos which show considerable structure and connect the interstellar medium (ISM, the gas between the stars) within the galaxy disk to the surrounding environment. The evidence is mounting that these halos are dynamic entities; that is, they manifest the expulsion of dust, gas (ionized, neutral and molecular), cosmic rays, and magnetic fields from galaxy disks. What is not yet clear is how many and what type of galaxy is more likely to display such halos, how much expelled material cycles back to the disk again, and how much material leaves the galaxy, enriching the intergalactic medium (IGM, the low density gas between galaxies). We know that such outflows (or `feedback') play a crucial role in the formation of galaxies, yet the nature and details of this activity are not well known. The evidence suggests that galaxy evolution (including that of our own Milky Way) is strongly influenced by such activity, yet we do not even know the main drivers of such activity.

螺旋星系被气态光环所包围，它们显示出相当大的结构，并将星系盘内的星际介质（ISM，恒星之间的气体）连接到周围环境中。 有证据表明这些光环是动态实体。也就是说，它们表现出从星系磁盘中驱除灰尘，气体（电离，中性和分子），宇宙射线和磁场。 尚不清楚的是，更有可能显示这样的光晕的星系，又有多少排出的材料循环再次回到磁盘上，以及多少材料离开银河系，富集了银河系介质（IgM，星系之间的低密度气体）。 我们知道，这种流出（或“反馈”）在星系的形成中起着至关重要的作用，但是这项活动的性质和细节并不众所周知。 证据表明，星系进化（包括我们自己的银河系的进化）受到这种活动的强烈影响，但我们甚至不知道这种活动的主要驱动因素。