LIGO发布新闻:再次探测到引力波! 精选

已有 6559 次阅读 2016-6-16 08:58 |个人分类:科学新闻|系统分类:海外观察| 引力波, LIGO


此次探测到的双黑洞并合事件被称之为 The Boxing Day event.

The Boxing Day event differed from the LIGO's first gravitational wave observation in some important ways, however.

1.The gravitational wave arrived at the two detectors at almost the same time, indicating that the source was located somewhere in a ring of sky about midway between the two detectors. Knowing our detector sensitivity pattern, we can add that it was a bit more likely overhead or underfoot instead of to the West or the East. With only two detectors, however, we can't narrow it down much more than that. This differs from LIGO's first detected signal (GW150914, from 14 September 2015), which came from the 'southeast', hitting Louisiana's detector before Washington's.

2.The two merging black holes in the Boxing Day event were less massive (14 and 8 times the mass of our sun) than those observed in the first detection GW150914 (36 and 29 times the mass of our sun). While this made the signal weaker than GW150914, when these lighter black holes merged, their signal shifted into higher frequencies bringing it into LIGO’s sensitive band earlier in the merger than we observed in the September event. This allowed us to observe more orbits than the first detection–some 27 orbits over about one second (this compares with just two tenths of a second of observation in the first detection). Combined, these two factors (smaller masses and more observed orbits) were the keys to enabling LIGO to detect a weaker signal. They also allowed us to make more precise comparisons with General Relativity. Spoiler: the signal agrees, again, perfectly with Einstein’s theory.

3.Last but not least, the Boxing Day event revealed that one of the initial black holes was spinning like a top! – and this is a first for LIGO to be able to state this with confidence. A spinning black hole suggests that this object has a different history –- e.g. maybe it 'sucked in' mass from a companion star before or after collapsing from a star to form a black hole, getting spun-up in the process.



10 吕喆 李颖业 郑小康 田云川 decipherer shenlu guoyanghuawu yangb919 xlianggg sunyang86

该博文允许注册用户评论 请点击登录 评论 (5 个评论)


Archiver|手机版|科学网 ( 京ICP备07017567号-12 )

GMT+8, 2022-1-28 14:47

Powered by

Copyright © 2007- 中国科学报社