首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Star birth, which transformed primordial gas into the countless starry galaxies of the present day universe, surged to high leve
Star birth, which transformed primordial gas into the countless starry galaxies of the present day universe, surged to high leve
admin
2009-02-10
48
问题
Star birth, which transformed primordial gas into the countless starry galaxies of the present day universe, surged to high levels much earlier than astronomers had thought. Two teams of observers have looked into the early universe for the longwavelength radiation that signal star formation in dusty young galaxies. In tomorrow’s Nature, they report seeing galaxies rapidly spawning stars when the universe was less than a third of its present age.
Astronomers have been searching at great distance -- which correspond to earlier times -- to find the heyday of star birth. But interstellar dust is thick in star-forming regions hiding the light of hot young stars and reradiating it in the infra red. Observations by infrared satellites have already revealed large number of star-forming galaxies as much as halfway back to the big bang. But for even older, more distant stars and galaxies, the expansion of the universe stretches the infrared radiation into the submillimeter waveband, a twilight region of the spectrum between infrared and radio.
Earlier this year, a U. K. team led by Michael Rowan -- Robinson of London’s Imperial College pointed a submillimeter telescope on Mauna Kea, Hawaii, at the Hubble Deep Field, the small patch of sky where the Hubble Space Tele scope captured optical images of some of the most distant galaxies ever. Five of the brightest submillimeter sources they found match up with faint, old galaxies in the Hubble image, and four of the five date from when the universe was between a third and a fifth of its present age -- up to 9 billion years ago. Their submillimeter brilliance indicates that these galaxies are spawning stars perhaps 100 times faster than our own galaxy, says team member James Dunlop of the University of Ed inburgh. A U. S. -Japanese group has made other submillimeter images that support this picture of frenzied star birth in the early universe.
The observations are "a very exciting new development," says Max Pettini, an astrophysicist at Britain’s Royal Green wich Observatory. Star formation, he says, is "part and parcel of the broader question of how the universe evolved from the smooth conditions of the big hang into the galaxies we see today. "However, Charles Steidel of the California Institute of Technology cautions that the distance and hence the age of these submillimeter sources is "somewhat ambiguous, "because of the submillimeter camera’s coarse resolution.
We can infer that the word "ambiguous" in the last paragraph probably means ______.
选项
A、clear
B、uncertain
C、mysterious
D、satisfying
答案
B
解析
最后一段最后一句话意思为,“然而,加州理工学院的查尔斯,斯戴德提醒说,由于亚毫米摄像机调焦不准,它所提供的有关距离及年龄的资料有点模糊不清”,所以推断出B正确。
转载请注明原文地址:https://kaotiyun.com/show/D26K777K
0
专业英语四级
相关试题推荐
Countlessmedicalstudieshaveconcludedthatplayingtoomanyvideogamescanbeharmfultoone’shealth.Now,however,itturn
IfNajibullahZaziiseverythingtheFBIsaysheis,thentheAfghan-bornDenverairport-shuttle-busdriverrepresentsanewkin
IfNajibullahZaziiseverythingtheFBIsaysheis,thentheAfghan-bornDenverairport-shuttle-busdriverrepresentsanewkin
IfNajibullahZaziiseverythingtheFBIsaysheis,thentheAfghan-bornDenverairport-shuttle-busdriverrepresentsanewkin
A、Upto12hours.B、Upto20hours.C、Upto18hours.D、Upto24hours.B细节题。录音中提到:underpresentimmigrationregulations,intern
ThepresentdayAfrican-Americanpopulation,likemanyotherethic【M1】______groups,isseveralgenerationsremovedfromtheir
ThepresentdayAfrican-Americanpopulation,likemanyotherethic【M1】______groups,isseveralgenerationsremovedfromtheir
随机试题
下列细菌感染常见铁锈色痰的是
剩余法除适用于土地估价外,也可用来估测具体开发项目的预期利润。()
镇区用地规划布局的镇布局原则有()。
下列主体中,可以作为会计主体的有()。
下列说法中不正确的是()。
关于企业所得税,下列说法正确的是()。
根据材料回答下列问题。华尔街的金融海啸,将颠覆笼罩在世界许多人头脑中的一种根深蒂固的盲目崇拜和迷信,一种曾经被灌输给世界人民的历史观和文化观。那种弥漫全世界的迷信或思潮究竟是什么呢?简言之,它是一种“新蒙昧主义”,也就是一种“美国什么都好”、“代表了人类
假如一个人,从他的少年时代开始,就时刻地守住________,用它来学习、劳动,________决不容忍无聊的玩乐来剥夺任何一个早晨,也决不允许让缥缈的幻想来骗取任何一个夜晚,每迎接一个黎明都有的斗志,每送走一个黄昏,都有前进一步的喜悦,那么,他的生命将成
“批判的武器当然不能代替武器的批判,物质的力量只能用物质的力量来摧毁;但理论一经群众掌握,也会变成物质力量。”这一论断体现出的哲学思想有
Genesarethebiologicalinstructions______ineverycell.
最新回复
(
0
)