Toward the event horizon with Astro-H

在大多数星系的中心都存在着一个比太阳大几百万甚至几十亿倍的超大质量黑洞。其中一些怪物非常活跃，它们可以使周围的物质比其宿主星系中的所有恒星都亮。最接近黑洞的物质，就在它即将跳出事件视界时，受到宇宙中最剧烈的条件的影响。黑洞的极端引力可以将恒星撕裂，并以接近光速的速度将物质抛向周围，然后最终被吞噬。有时这种物质会被猛烈地抛出，以至于它完全从黑洞区域被抛出，并被抛回星系附近，在那里它可能对宿主星系的条件产生巨大的影响。最靠近黑洞的物质被加热到数百万度甚至更热，并以X射线能量辐射。

A supermassive black hole that is millions or even billions of times more massive than the Sun resides at the centres of most galaxies. Some of these monsters are so active that they can make the surrounding material shine brighter than all the stars in its host galaxy. The material closest to the black hole, just as it is about to plunge beyond the event horizon, is subjected to the most violent conditions in the Universe. The extreme gravity of the black hole can tear stars apart and fling matter around at velocities close to the speed of light before it is finally ingested. Sometimes this material can be thrown out so violently that it is completely ejected from the black hole region and hurled back into the galactic neighbourhood where it may have a resounding effect on the conditions in the host galaxy. The matter closest to the black hole is heated to millions of degrees or even hotter, and it radiates at X-ray energies.