Constraining accretion and relativistic jet physics with multi-wavelength observations of accreting compact objects

通过对吸积致密物体的多波长观测来约束吸积和相对论射流物理

• 批准号: 402752-2011
• 负责人: Sivakoff, GregoryRobert
• 金额: $ 1.97万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=488164
• 关键词: Constraining; accretion; relativistic; jet; physics

White dwarfs, neutron stars, and black holes are some of the most extreme objects in the Universe. In these dense objects, a mass similar to that of the Sun can be concentrated in objects the size of the Earth (white dwarfs), the size of a city (neutron stars), or an infinitesimal point (black holes). Despite their exotic nature, these compact objects are also home to processes that appears repeatedly in the Universe over a variety of scales, accretion discs and collimated outflows of jets. Accretion discs are structures around central objects where material flows onto the central object. In some cases, material may manage to flow out, presumably perpendicular to the disc, in jets. This combination of processes is seen across a wide variety of astronomical objects: the discs from which planets form accrete onto young stars and can produce jets; material from the outer envelopes of stars orbiting around white dwarfs, neutron stars, and stellar-mass black holes accrete onto the compact objects and jets of material flowing near the speed of light (relativistic jets) can form; and material at the center of galaxies can accrete onto supermassive black holes, also producing relativistic jets. Despite the universal nature of accretion physics and jet formation, there are many open questions. Relativistic jets are also extremely important as they can significantly impact their environment. Astronomers currently believe that the relativistic jets from supermassive black holes may play an important role in how galaxies form.

白矮星、中子星和黑洞是宇宙中一些最极端的天体。在这些致密的天体中，类似太阳的质量可以集中在地球大小的天体(白矮星)、城市大小的天体(中子星)或无穷小的点(黑洞)中。尽管这些致密天体具有奇特的性质，但它们也是在宇宙中反复出现的过程的家园，这些过程以各种尺度、吸积盘和平行的喷流流出。吸积盘是围绕中心物体的结构，物质流到中心物体上。在某些情况下，物质可能会设法以射流的形式流出，假定是垂直于圆盘。这一过程的组合可以在各种各样的天文物体上看到：行星形成的圆盘附着在年轻恒星上，可以产生喷流；围绕白矮星、中子星和恒星质量的黑洞运行的恒星的外层包层的物质附着在致密物体上，可以形成接近光速的物质喷流(相对论喷流)；星系中心的物质可以附着在超大质量黑洞上，也产生相对论喷流。尽管吸积物理和喷流形成具有普遍的性质，但仍有许多悬而未决的问题。相对论喷流也是极其重要的，因为它们可以显著影响环境。天文学家目前认为，来自超大质量黑洞的相对论喷流可能在星系的形成过程中发挥重要作用。