本帖最后由 gohomeman1 于 2009-8-7 16:06 编辑
http://hubblesite.org/newscenter/archive/releases/2009/24/full/
The full news release story:
报告全文
Looking almost 11 billion years into the past, astronomers have measured the motions of stars for the first time in a very distant galaxy and clocked speeds upwards of one million miles per hour, about twice the speed of our Sun through the Milky Way.
回溯大约110亿年前的早期宇宙，天文学家第一次测量了极其遥远星系中的恒星运动。它们的运动时速高达一百万英里，大约是我们太阳绕银河核心旋转速度的2倍。天文学家为如何形成这些致密星系伤脑筋，也许它们最终成为大星系的致密核球区了。
The fast-moving stars shed new light on how these distant galaxies,which are a fraction the size of our Milky Way, may have evolved into the full-grown galaxies seen around us today. The results will be published in the August 6, 2009 issue of the journal Nature, with acompanion paper in the Astrophysical Journal.
快速移动的恒星流泻出它们的第一线星光照亮了星系，虽然这些星系的大小仅相当于银河系的一角，但它们终将演化成今天我们周围的成熟大星系。报告将刊登在2009.8.6出版的《自然》杂志期刊上，同时刊发在《天体物理学》期刊上。
"This galaxy is very small, but the stars are whizzing around as if they were in a giant galaxy that we would find closer to us and not so far back in time," says Pieter van Dokkum, professor of astronomy and physics at Yale University in New Haven, Conn., who led the study. It is still not understood how galaxies like these, with so much mass in such a small volume, can form in the early universe and then evolve into the galaxies we see in the more contemporary, nearby universe,which is about 13.7 billion years old.
美国康涅狄格州纽黑文市耶鲁大学，研究团队带头人、天体物理学家兼天文学家皮耶特.冯·多克姆说：“这个星系非常小，但其中恒星的运动极快，貌似它们就在我们周围的那些巨型星系中而不是在深远的过去。”自137亿年前宇宙诞生至今，我们尚不明白早期宇宙中是如何形成如此小而恒星密度如此高的星系的，然后它们又是如何演化为我们当前观测到的大星系的。
The work by the international team combined data collected using NASA's Hubble Space Telescope with observations taken by the 8-meter Gemini South telescope in Chile. According to van Dokkum, "The Hubble data, taken in 2007, confirmed that this galaxy was a fraction the size of most galaxies we see today in the more evolved, older universe. The giant, 8-meter mirror of the Gemini telescope then allowed us to collect enough light to determine the overall motions of the stars using a technique not very different from the way police use laserlight to catch speeding cars." The Gemini near-infrared spectroscopic observations required an extensive 29 hours on the sky to collect the extremely faint light from the distant galaxy, which goes by the designation 1255-0.
一个国际团队的工作综合了哈勃太空望远镜和智利双子南座8米大型望远镜的数据。据冯·多克姆说：“哈勃的数据摄于2007年，它确认了这个星系仅仅相当于我们现在看见的大型成熟星系的一丁点大；而双子南座的8米巨型望远镜让我们能收集足够的星光以测定其中恒星的运动全貌。我们使用的方法与警察采用激光测速仪抓获超速汽车大同小异。”双子座近红外摄谱仪对天空中特定区域曝光29小时左右，以获取编号为1255-0的超远距离星系的极度黯淡的星光。
"By looking at this galaxy we are able to look back in time and see what galaxies looked like in the distant past when the universe was very young," says team member Mariska Kriek of Princeton University in Princeton, N.J. 1255-0 is so far away that the universe was only about 3 billion years old when its light was emitted.
“通过观测这个星系我们能够回溯过去，去看看在宇宙还相当年轻的遥远古老时代，星系是怎样的”，普林斯顿大学（位于美国新泽西州普林斯顿市）的玛丽斯卡.克瑞克说。 1255-0星系是如此遥远，以致于它的星光上路（到我们）时，宇宙仅有30亿岁。
Astronomers confess that it is a difficult riddle to explain how such compact, massive galaxies form, and why they are not seen in the current, local universe. "One possibility is that we are looking at what will eventually be the dense central region of a very large galaxy," explains team member Marijn Franx of Leiden University in the Netherlands. "The centers of big galaxies may have formed first,presumably together with the giant black holes that we know exist in today's large galaxies that we see nearby."
如此致密的大质量星系是如何形成的，现在的宇宙又为何观测不到，天文学家承认这是个难题。“一种可能就是我们正在观测的是最终演化为一个大型星系的致密核球区域，”荷兰莱顿大学的Marijn Franx解释道。“核球区域和其中的超级黑洞可能先期形成，就像存在于我们附近的那些大型星系一样。”（非常遥远的星系也必然是非常早期的星系，而我们附近的星系都是星系比较近代的面貌——gohomeman1注）
To witness the formation of these extreme galaxies astronomers planto observe galaxies even farther back in time in great detail. By using the Wide Field Camera 3, which was recently installed on the Hubble Space Telescope, such objects should be detectable. "The ancestors of these extreme galaxies should have quite spectacular properties as they probably formed a huge amount of stars, in addition to a massive black hole, in a relatively short amount of time," says van Dokkum.
为亲眼目击这些极端星系形成的第一手资料，天文学家计划更详细地观测宇宙更早年代的星系。哈勃太空望远镜的最新利器——第3代广域相机（WFC3）将能观测到这些极度遥远的天体。“这些致密星系的祖先在极短时间内形成巨量恒星的星暴景象该是多壮观啊，还有形成那个超级黑洞，”冯·多克姆补充道。
This research follows recent studies revealing that the oldest, most luminous galaxies in the early universe are very compact yet surprisingly have stellar masses similar to those of present-day elliptical galaxies. The most massive galaxies we see in the local universe (where we don't look back in time significantly) that have a mass similar to 1255-0 are typically five times larger than the young compact galaxy. How galaxies grew so much in the past 10 billion years is an active area of research, and understanding the dynamics in these young compact galaxies is a key piece of evidence in eventually solving this puzzle.
这一最新研究结果揭示了早期宇宙中那些古老的极为明亮的星系是非常致密的，并令人惊讶的具有与现在的椭圆星系相当的恒星质量。我们附近宇宙中的大型星系（显然我们也没回溯多古老的年代），如果质量与年轻的致密星系1255-0相当，直径就要大5倍。100亿年前早期星系的成长研究是当前的一个热点，而搞清这些致密星系的天体动力学关系是最终解决这个难题的一把钥匙。
The Hubble Space Telescope observations were made with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).
执行本次观测的哈勃太空望远镜仪器是近红外相机和多天体摄谱仪（NICMOS）.
The Gemini observations were made using the Gemini Near Infrared Spectrograph (GNIRS), which is currently undergoing upgrades and will be reinstalled on the Gemini North telescope on Mauna Kea in 2010.
双子南座天文台的观测仪器是双子近红外摄谱仪（GNIRS），它当前正在升级并将于2010年重新安装到双子北座天文台的（夏威夷）莫纳克亚峰顶。
For illustrations and more information, visit:
更多详细信息和图表，请参阅以下网址：
http://hubblesite.org/news/2009/24
http://www.gemini.edu
CONTACT
联系人
Ray Villard
雷.维拉德
Space Telescope Science Institute, Baltimore, Md.
马里兰州 巴尔的摩市 太空望远镜科研所
410-338-4514
villard@stsci.edu
Peter Michaud
彼得.米肖
Gemini Observatory, Hilo, Hawaii
夏威夷 希洛市 双子座天文台
808-974-2510
pmichaud@gemini.edu |
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