Illustration: An Early Quasar
Illustration Credit & License: ESO, M. Kornmesser
Explanation: What did the first quasars look like? The nearest quasars are now known to involve supermassive black holes in the centers of active galaxies. Gas and dust that falls toward a quasar glows brightly, sometimes outglowing the entire home galaxy. The quasars that formed in the first billion years of the universe are more mysterious, though. Featured, recent data has enabled an artist’s impression of an early-universe quasar as it might have been: centered on a massive black hole, surrounded by sheets of gas and an accretion disk, and expelling a powerful jet. Quasars are among the most distant objects we see and give humanity unique information about the early and intervening universe. The oldest quasars currently known are seen at just short of redshift 8 — only 700 million years after the Big Bang — when the universe was only a few percent of its current age.
Tomorrow’s picture: open space
图示：宇宙早期的类星体
图示提供与授权: ESO, M. Kornmesser
说明: 第一批类星体长什么模样呢？我们附近的类星体，目前认为与活跃星系核心的超大质量黑洞有关。而当气体和尘埃掉入这种类星体时，所发出的辉光有时甚至比它所在的星系还来得亮。不过，出现在宇宙诞生后10亿年之内的类星体，则较神秘难解。这张根据最新资料所建构的画家图示，呈现宇宙早期类星体的可能模样： 在其中心的大质量黑洞，周围环拱着片状的气体及吸积盘，并射出很强烈的喷流。类星体除了是人类可见的最遥远天体之一，同时也带着早期及中后期宇宙的独特资讯。目前所知的最古老类星体之红移略小于8，出现的年代相当于在宇宙发生大爆炸后的7亿年，该时宇宙之年龄大约只有目前的百分之五。
明日的图片: open space
[词汇学习]
中文丨Chinese Pinyin丨English
[类星体]lèi xīngtǐ丨quasar
[超大质量黑洞]chāodà zhìliàng hēidòng丨supermassive black hole
[活跃星系]huóyuè xīngxì丨active galaxies
[母星系]mǔ xīngxì丨home galaxies
[吸积盘]xī jī pán丨accretion disk
[喷流]pēn liú丨jet
[红移]hóng yí丨redshift
[大爆炸]dà bàozhà丨Big Bang
