星系形成吸收尘埃使宇宙变得更加清洁
文章来源:未知 文章作者:enread 发布时间:2016-06-30 08:41 字体: [ ]  进入论坛
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The Universe is becoming gradually cleaner as more and more cosmic dust is being mopped up by the formation of stars within galaxies1, an international team of astronomers2 has revealed. Peering back 12 billion years using the Herschel space telescope to produce far-infrared images of the sky, the team led by researchers at Cardiff University has been able to observe the very early formation of galaxies and compare them to galaxies that have formed much more recently.
 
The results showed that stars were forming inside galaxies much faster in the past compared to today, and that this rapid star birth is using up more and more of the cosmic dust that is ubiquitous in the Universe.
 
Cosmic dust is comprised of tiny solid particles that are found everywhere in space between the stars. The dust and the gas in the universe is the raw material out of which stars and galaxies form.
 
Though this blanket of material is key to the formation of stars and galaxies, it also acts as a sponge, absorbing almost half of the light emitted by stellar objects and making them impossible to observe with standard optical telescopes.
 
With the launch of the Herschel space telescope in 2009, researchers were provided with the perfect tool for probing this hidden universe. Owing to a collection of sensitive instruments, mirrors and filters, the Herschel telescope had the capacity to detect the dust through the far-infrared emission3 it emits, revealing the existence of stars and galaxies hidden by the dust.
 
Professor Steve Eales, a co-leader of the project from Cardiff University's School of Physics and Astronomy, said: "We were surprised to find that we didn't need to look far in the past to see signs of galaxy4 evolution. Our results show that the reason for this evolution is that galaxies used to contain more dust and gas in the past, and the universe is gradually becoming cleaner as the dust is used up."


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1 galaxies fa8833b92b82bcb88ee3b3d7644caf77     
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。
2 astronomers 569155f16962e086bd7de77deceefcbd     
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》
3 emission vjnz4     
n.发出物,散发物;发出,散发
参考例句:
  • Rigorous measures will be taken to reduce the total pollutant emission.采取严格有力措施,降低污染物排放总量。
  • Finally,the way to effectively control particulate emission is pointed out.最后,指出有效降低颗粒排放的方向。
4 galaxy OhoxB     
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。
TAG标签: dust universe cosmic
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