星系壁纸
by Top: NASA/JPL-Caltech. Lower-left: Hubble Legacy Archive, NASA, ESA. Bottom-right: NASA/ESA
NASA Image Library · 公有领域（Public Domain）
关于这张图
Top: An illustration of NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, in orbit. The unique school bus-long mast allows NuSTAR to focus high energy X-rays. Lower-left: A color image from NASA's Hubble Space Telescope of one of the nine galaxies targeted by NuSTAR in search of hidden black holes. Bottom-right: An artist's illustration of a supermassive black hole, actively feasting on its surroundings. The central black hole is hidden from direct view by a thick layer of encircling gas and dust. http://photojournal.jpl.nasa.gov/catalog/PIA19348
