矮星系赫見黑洞 可究宇宙起源新聞網址 : http://tw.news.yahoo.com/article/url/d/a/110111/19/2kmz5.html
（法新社華盛頓10日電） 美國天文學家在鄰近銀河系旁發現1黑洞，其質量為太陽的1百萬倍，此發現有助了解宇宙的起源。
美國天文學會（American Astronomical Society）今天宣布，在某個「矮星系」（dwarf galaxy）中令人訝異的發現，證明黑洞是在該星系之前就形成。
維吉尼亞大學（University of Virginia）研究員瑞恩斯（Amy Reines）表示：「此發現提供星系早期演化的重要線索，這是從前不曾觀察到的。」
天文學家已研究韓尼茲（Henize）2-10星系多年，此星系距地球3000萬光年，形成恆星的速度極快。科學家認為此星系類似宇宙初期最早成立的星系群。
瑞恩斯與維吉尼亞大學和美國國家無線電天文台（National Radio Astronomy Observatory, NRAO）的西瓦科夫（Gregory Sivakoff）、強生（Kelsey Johnson），及NRAO的布羅根（Crystal Brogan），以國家科學基金會（National Science Foundation）的超大陣列電波望遠鏡和哈伯太空望遠鏡（Hubble Space Telescope）觀測韓尼茲2-10星系。
強生表示：「此星系可能類似早期宇宙的星系。宇宙初形成時，銀河才正要形成且經常碰撞在一塊。此銀河包括超級黑洞在內的所有物質，都能帶給我們重要新線索，有助了解當時黑洞及星系是如何形成的。」（譯者：中央社陳禹安）1
Rachel Kaufmanfor National Geographic NewsPublished January 10, 2011A supermassive black hole discovered inside a nearby dwarf galaxy may help explain how galaxies grew in the early universe.
At its center, nearly every large galaxy contains a supermassive black hole surrounded by a big bulge of stars.
But whether the black hole or the bulge formed first has long been a chicken-and-egg question in astronomy.(Related: "'Hidden' Black Holes Discovered in Distant Galaxies.")New x-ray and radio observations of the dwarf galaxy Henize 2-10 show that, while the tiny galaxy lacks a bulge, it very likely contains a supermassive black hole—one about a quarter as large as the black hole at the center of our Milky Way.
Henize 2-10 is small and irregularly shaped, and it's actively forming stars, which means it's very similar to early galaxies, researchers say.
The new finding therefore suggests that early galaxies also formed their central black holes before developing bulges.
"This is certainly evidence that the black holes came first," said Amy Reines, the doctoral candidate at the University of Virginia who discovered the black hole.But "I wouldn't say it's a done deal, because we don't know for sure there's only one path to galaxy formation."Galaxy Evolution in Action?Reines had been studying star-forming regions in Henize 2-10 using the Very Large Array in New Mexico and the Hubble Space Telescope when she found a compact source of radio waves emanating from the galaxy.The orbiting Chandra X-ray Observatory later revealed x-rays being emitted from the same source.The radiation pattern is "characteristic of a black hole feeding into its environment," Reines said. But unlike smaller black holes that form from collapsed stars, this black hole is about a million times the mass of a star. (Seeblack hole pictures.)Such supermassive black holes have been found in small galaxies before, but those galaxies are "like scaled-down versions of normal galaxies," Reines said."Henize 2-10 has this irregular shape ... and the star formation really sets it apart," she said. "We think we might be witnessing the early phase of galaxy evolution."(Related: "Black Hole Blasts Superheated Early Universe.")Meg Urry, a Yale University astronomer who was not involved in the current research, called the study well done, noting that "they have a lot of data."But as for whether Henize 2-10 is a key to unlocking the early universe, "you can never hang much on one object. They've done as well as can be done with only one object."The black-hole research appeared in the January 9 online edition of the journalNature.
更新日期:2010/12/21 10:51 記者曹逸雯卅台北報導