哈勃观测到宇宙间的相互作用
This image from the NASA/ESA Hubble Space Telescope feels incredibly three-dimensional for a piece of deep-space imagery. The image shows Arp 282, an interacting galaxy pair composed of the Seyfert galaxy NGC 169 (bottom) and the galaxy IC 1559 (top). Interestingly, both galaxies have monumentally energetic cores known as active galactic nuclei (AGN), although that is difficult to tell from this image, which is fortunate. If the image revealed the full emission of both AGNs, their brilliance would obscure the beautifully detailed tidal interactions we see in this image. Tidal forces occur when an object’s gravity causes another object to distort or stretch. The direction of tidal forces is away from the lower-mass object and toward the higher mass object. When two galaxies tidally interact, gas, dust, and even entire star systems can move toward one galaxy and away from the other. The image reveals this process in action as delicate streams of matter visibly link the two galaxies.
Astronomers now accept that an important aspect of how galaxies evolve is the way they interact with one another. Galaxies can merge, collide, or brush past one another – each interaction significantly affecting their shapes and structures. As common as such interactions may be, it is rare to capture an image of two galaxies interacting in such a visibly dynamic way.
Text credit: European Space Agency (ESA)
Image credit: ESA/Hubble & NASA, J. Dalcanton, Dark Energy Survey, Department of Energy (DOE), Cerro Tololo Inter-American Observatory/NoirLab/National Science Foundation/Association of Universities for Research in Astronomy (AURA), Sloan Digital Sky Survey (SDSS); Acknowledgment: J. Schmidt
这张来自NASA/ESA哈勃太空望远镜的深空图像给人一种难以置信的三维感觉。这张照片显示了Arp 282，一个相互作用的星系对，由塞弗特星系NGC 169（底部）和星系IC 1559（顶部）组成。有趣的是，这两个星系都有被称为活动星系核（AGN）的巨大能量核心，尽管从这张图片上很难看出来，这也是幸运的。如果这张照片显示了两个AGN的全部发射，那么它们的亮度将会掩盖我们在这张照片中看到的漂亮而详细的潮汐相互作用。当一个物体的重力导致另一个物体扭曲或伸展时，就会产生潮汐力。潮汐力的方向是远离低质量的物体，而朝着高质量的物体。当两个星系潮汐地相互作用时，气体、尘埃甚至整个恒星系统都可以向一个星系移动，并远离另一个星系。这幅图像揭示了这一过程，微妙的物质流明显地连接着两个星系。
天文学家现在承认星系进化的一个重要方面是它们相互作用的方式。星系可以相互合并、碰撞或擦身而过——每一次的相互作用都会显著地影响它们的形状和结构。尽管这种相互作用可能很常见，但捕捉到两个星系以如此明显的动态方式相互作用的图像却很少见。
文字来源：European Space Agency (ESA)
影像来源：ESA/Hubble & NASA, J. Dalcanton, Dark Energy Survey, Department of Energy (DOE), Cerro Tololo Inter-American Observatory/NoirLab/National Science Foundation/Association of Universities for Research in Astronomy (AURA), Sloan Digital Sky Survey (SDSS); 致谢：J. Schmidt