黑洞，引力如此巨大，以致於任何靠近它的物質都會墜入其中，甚至連光都無法逃逸。我們一直認為它會吞噬星球，可是最新的觀察竟然發現恰恰相反——黑洞孕育了星系！
天文學家觀測了一系列的星系，發現基本上黑洞的大小與其所在星系中心由星塵組成的核球大小有直接的比例關係：黑洞的質量通常是核球質量的千分之一。
但是當天文學家觀測更遙遠的星系時，驚訝地發現黑洞與核球的質量不再維持固定的比例，而且最遙遠的星系中的黑洞質量比預期的還要大的更多！
因為愈遙遠的星系其年齡愈古老，也代表我們觀測到的影像愈接近宇宙誕生之際（如果某個星系距離我們五十億光年，就表示那裡發出的光要花五十億年的時間才到達地球，也就是說我們現在看到的是五十億年前的影像）。如果黑洞是藉由吞噬週遭星球與氣體而增加質量，照理說宇宙早期星系裡的黑洞應該還來不及「長大」啊，為甚麼那時黑洞質量佔星系質量的比例反而比較高？
按此推測，難道是先有黑洞存在，然後才孕育了週遭的星系？聽起來實在不可思議，不過能有更好的解釋嗎？
天文學家希望正在新墨西哥州與智利建造中的天文望遠鏡未來能提供更佳的數據。如果證實確是如此，也許宇宙就不會如我們本來以為的：終將走向死寂的命運；反而可以生生不息呢！
Yo Galaxy's Mama Is a Black Hole
By Clara Moskowitz January 07, 2009
Lurking deep inside the center of almost all galaxies is a ravenous, super-massive black hole, and new research suggests the black hole may have given birth to its galaxy. This could be the answer to a long-standing astronomical chicken-and-egg problem.
By observing a series of galaxies and measuring the motions of swirling gas inside them, astronomers were able to weigh the galaxies and their resident black holes. They found that in general, there is a direct relationship between the size of a black hole and the size of the central bulge of stars and gas in the galaxy around it: Black holes usually weigh about one one-thousandth of the mass of the galactic bulge.
But when the researchers looked at galaxies that were farther away, and thus effectively dating from earlier periods in the universe’s history (because the more distant we look, the longer an object’s light has taken to reach us, so the older it is), they found a surprising pattern.
The usual mass ratio between black hole and galaxy didn’t hold up. Instead, the black holes in the farthest away galaxies — the ones we are seeing in the youngest stage of development — were much larger than expected.
"The simplest conclusion is that the black holes come first and they somehow grow the galaxy around them," said astronomer Chris Carilli of the National Radio Astronomy Observatory during a briefing Wednesday at the American Astronomical Society's meeting in Long Beach, California.
If this is true, it raises many significant questions about why the black holes and galaxies are so linked, and how black holes help galaxies grow.
"We don't know what mechanism is at work here, and why, at some point in the process, the 'standard' ratio between the masses is established," said Caltech astronomer Dominik Riechers in a press release. Riechers also worked on the study.
Some theorize that the strong winds and jets surrounding black holes could help feed star formation and induce galaxies to grow. But the violent environments of black holes have also been thought too chaotic to harbor stable star formation.
The researchers hope to better understand the seemingly symbiotic relationship between galaxies and their gobbling black hole inhabitants when new observation tools come online soon. The Expanded Very Large Array (EVLA) being built in New Mexico, and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, expected to be completed by 2012, should dramatically increase the sensitivity and resolution available for studies of distant galaxies.
"We really do need to confirm this with further observations," Carilli said. "In fact the future looks extremely bright for these kinds of studies."
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