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

白色矮星、中子星和黑洞是宇宙中一些最极端的天体。在这些致密的物体中，类似于太阳的质量可以集中在地球大小的物体（白色矮星），城市大小的物体（中子星）或无限小的点（黑洞）。尽管它们具有奇异的性质，但这些紧凑的物体也是宇宙中反复出现的各种尺度，吸积盘和准直喷流的过程的家园。吸积盘是围绕中心物体的结构，其中材料流到中心物体上。在某些情况下，物质可能会设法流出，大概垂直于光盘，在射流。这种过程的结合在各种各样的天体上都可以看到：行星形成的圆盘与年轻恒星吸积，并可以产生喷流;围绕白色矮星、中子星和恒星质量黑洞运行的恒星的外层物质与致密天体吸积，并以接近光速的速度流动（相对论喷流）可以形成;星系中心的物质可以吸积到超大质量黑洞上，也会产生相对论喷流。尽管吸积物理学和喷流形成具有普遍性，但仍有许多悬而未决的问题。相对论性喷流也非常重要，因为它们可以显著影响其环境。天文学家目前认为，来自超大质量黑洞的相对论性喷流可能在星系形成中发挥重要作用。

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.