VOA标准英语2009年-Astronomers Detect Most Distant Cosmic Obj

By Jessica Berman
Washington
29 October 2009

 
Ultraviolet, X-Ray images of gamma-ray burst 
Astronomers¹ have discovered evidence of the oldest and most distant cosmic event ever detected, a burst from a dying star that occurred 13 billion years ago, very soon after the birth of the universe. Scientists hope the discovery of the ancient explosion will bring new insights into the evolution of the cosmos².

Astronomers say the high-energy gamma-ray burst from the dying star occurred 630 million years after the so-called Big Bang that is believed to have created the universe nearly 14 billion years ago.

The discovery suggests the so-called Dark Age of the universe, the period after the Big Bang before first-generation stars could fill the cosmos with light, ended much earlier than previously³ thought. Prior to the discovery, the earliest stellar explosion on record occurred 200 million years later and involved a star much closer to Earth.

Nial Tanvir of the University of Leicester in England headed one of two teams of scientists that discovered the gamma ray blast marking the death of the star.

Tanvir says the explosion of the dying star, or supernova, takes astronomers farther back in time than they have ever been. "... which really is the sort of era, the one last era, that is left undiscovered in cosmology. We have sort of mapped out the Universe to very great distances. And we are now sort of probing into the last era that we really have no observational clue as to what it was really like then," he said.

Tanvir says the discovery gives scientists a place in the sky to direct the earth-orbiting Hubble Space Telescope to look for other clues about the ancient Universe. "We think that if we look deeply enough, we will see a little galaxy⁴ there, a galaxy that hosted the star which exploded. Now we know exactly where to look. If we can go, for instance, as we are planning to do with the Hubble Space Telescope, and have a long hard stare at that patch of sky, then we may reveal that galaxy, and therefore learn something about the very early galaxies⁵," he said.

Dan Frail⁶ at the National Radio Astronomy Observatory⁷ in New Mexico is part of a team analyzing⁸ the waves of light given off by the star following its explosion, light that has taken more than 13 billion years to reach the Earth. Their observations may reveal what chemicals and compounds were dispersed⁹ during the Big Bang.

Until now, Frail says astronomers have presumed these ancient supernovae were brighter, hotter and more massive than the explosion of later generation stars. "And the next explosions that we study at these distances will tell us more about how the first generations of stars and first galaxies were formed. How the metals that make up the stars today got formed, how the light of the Universe got distributed. So, we have a lot to learn from studying these things; studying more examples of these objects," he said.

Two articles describing the discovery of the most distant cosmic object are published this week in the journal Nature.

1 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

2 cosmos   

n.宇宙；秩序，和谐

参考例句：

• Our world is but a small part of the cosmos.我们的世界仅仅是宇宙的一小部分而已。
• Is there any other intelligent life elsewhere in the cosmos?在宇宙的其他星球上还存在别的有智慧的生物吗？

3 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

4 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

5 galaxies   

星系( galaxy的名词复数 )； 银河系； 一群（杰出或著名的人物）

参考例句：

• Quasars are the highly energetic cores of distant galaxies. 类星体是遥远星系的极为活跃的核心体。
• We still don't know how many galaxies there are in the universe. 我们还不知道宇宙中有多少个星系。

6 frail   

adj.身体虚弱的；易损坏的

参考例句：

• Mrs. Warner is already 96 and too frail to live by herself.华纳太太已经九十六岁了，身体虚弱，不便独居。
• She lay in bed looking particularly frail.她躺在床上，看上去特别虚弱。

7 observatory   

n.天文台，气象台，瞭望台，观测台

参考例句：

• Guy's house was close to the observatory.盖伊的房子离天文台很近。
• Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。

8 analyzing   

v.分析；分析( analyze的现在分词 )；分解；解释；对…进行心理分析n.分析

参考例句：

• Analyzing the date of some socialist countries presents even greater problem s. 分析某些社会主义国家的统计数据，暴露出的问题甚至更大。 来自辞典例句
• He undoubtedly was not far off the mark in analyzing its predictions. 当然，他对其预测所作的分析倒也八九不离十。 来自辞典例句

9 dispersed   

adj. 被驱散的, 被分散的, 散布的

参考例句：

• The clouds dispersed themselves. 云散了。
• After school the children dispersed to their homes. 放学后，孩子们四散回家了。