TNG50模拟：星系团是如何形成的
Simulation TNG50: A Galaxy Cluster Forms
Video Credit: IllustrisTNG Project; Visualization: Dylan Nelson (Max Planck Institute for Astrophysics) et al.
Music: Symphony No. 5 (Ludwig van Beethoven), via YouTube Audio Library
Explanation: How do clusters of galaxies form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. A recent effort is TNG50 from IllustrisTNG, an upgrade of the famous Illustris Simulation. The first part of the featured video tracks cosmic gas (mostly hydrogen) as it evolves into galaxies and galaxy clusters from the early universe to today, with brighter colors marking faster moving gas. As the universe matures, gas falls into gravitational wells, galaxies forms, galaxies spin, galaxies collide and merge, all while black holes form in galaxy centers and expel surrounding gas at high speeds. The second half of the video switches to tracking stars, showing a galaxy cluster coming together complete with tidal tails and stellar streams. The outflow from black holes in TNG50 is surprisingly complex and details are being compared with our real universe. Studying how gas coalesced in the early universe helps humanity better understand how our Earth, Sun, and Solar System originally formed.
Tomorrow’s picture: unexpectedly red rays
TNG50模拟：星系团是如何形成的
影片提供: IllustrisTNG Project; 视象化: Dylan Nelson (Max Planck Institute for Astrophysics) et al.
配乐: Symphony No. 5 (Ludwig van Beethoven), via YouTube Audio Library
说明: 星系团是如何形成的？由于宇宙的变化过于缓慢难以追踪，只能借助较快速演化的电脑模拟来找答案。近来的一项努力是来自IllustrisTNG的TNG50模拟，而IllustrisTNG本身则是著名揭示模拟（Illustris Simulation）的进阶版。这部主题影片的前半部分追踪主要成分是氢的宇宙气体，从早期宇宙至现在如何演化成星系和星系团；其中，较明亮的色泽标示移动较快速的气体。而随着宇宙的年龄渐增，气体掉入重力阱、星系形成、星系自转、星系互撞及合并，在此同时，黑洞在星系的核心形成并高速喷出周围的气体。这部影片的后半部分转而追踪恒星，呈现星系团的形成过程，以及其中出现的潮汐尾和恒星流。TNG50模拟所呈现的黑洞外泛流意外的复杂，而其细部结构正在与真实宇宙相关的现象进行比对。研究在早期宇宙中气体如何聚合，可让人类更了解地球、太阳和太阳系当初是如何形成的。
明日的图片: unexpectedly red rays
