08年五大天文新发现 Top 5 Amazing Astronomy Discoveries in 2008
发布: 2008-12-28 11:41 | 作者: webmaster | 来源: 本站原创 | 查看: 307次
4. 千奇百怪的黑洞
黑洞拥有惊人的密度，任何物质——甚至包括光线在内——都无法逃脱它们的可怕引力。虽然仍无法直接进行观察，但天文学家还是根据黑洞对附近天体的影响，得出存在这种庞然大物的结论。2008年，天文学家发现了形形色色的黑洞家族成员，其中一些成员上演的行为似乎有些疯狂。在旋转速度方面，天文学家发现了旋转速度最快的黑洞——速度接近光速；在体积方面，他们又发现一个足以吞噬180亿个太阳的巨型黑洞。在这个巨型黑洞面前，天文学家于2008年发现的个头最小的黑洞就像是一个侏儒。科学家表示，黑洞家族中的“小不点”质量只有太阳的3.8倍左右，直径也不过15英里(24公里)。
除此之外，研究人员还在这一年发现了一些特大质量的黑洞，它们就位于很多或所有星系的中心，从喷流末端涌出巨型气泡。(物质被黑洞巨大引力“没收”后，能量会以放射物和高能粒子喷射方式被吐出黑洞。)巨泡最终破裂并释放内部的气态物质。热气释放过程阻止黑洞及其所在星系的体积出现巨大膨胀。此外，黑洞也能以“戴面具的逃亡者”形象示人。电脑模拟结果显示，在两个黑洞合并后，所产生的能量可能将这个新形成的黑洞“踢”出所在星系。同样是在2008年，科学家还第一次探测到一个“流浪”的黑洞，其移动速度达到每小时590万英里(每秒2650公里)。
4. Black hole antics
Black holes are so dense that nothing, not even light, can escape their gravitational grips. Though invisible, astronomers have inferred the presence of the dark behemoths from their effects on nearby objects. And this year, it seems, all the crazies came out of their cosmic closets.
Take the fastest spinning black hole, found to whirl around at speeds approaching the speed of light.
And when it comes to obesity, one black hole could've gobbled up 18 billion suns. This giant would dwarf the smallest black hole found this year, weighing in at about 3.8 times the mass of our sun and spanning just 15 miles (24 km) in diameter.
Researchers also found this year that some supermassive black holes, which reside at the centers of many or all galaxies, spew out giant bubbles from the tips of their jets. (As material falls into the gravitational clutches of a black hole, the energy can be spit out as jets of radiation and high-speed particles.) The bubbles ultimately pop, spilling their gaseous guts. Turns out, the hot gas keeps the black hole and its galaxy from ballooning to mega sizes.
Black holes can also take the form of "masked fugitive." Computer simulations revealed that when two black holes merge, the energy produced can kick the newly merged black hole clear out of its galaxy.
Also, for the first time this year, scientists detected such a rogue black hole racing along at 5,900,000 mph (2,650 kilometers per second).
