charles 2009-3-27 11:05
船帆座超新星爆炸遺骸
Vela Supernova Remnant in Visible Light
[img]http://i12.tinypic.com/49av4fm.jpg[/img]
影像版權: Digitized Sky Survey, ESA/ESO/NASA FITS Liberator
色彩合成: Davide De Martin (Skyfactory)
[color=navy]Explanation: [/color]
[color=dimgray]The explosion is over but the consequences continue. About eleven thousand years ago a star in the constellation of Vela could be seen to explode, creating a strange point of light briefly visible to humans living near the beginning of recorded history. The outer layers of the star crashed into the interstellar medium, driving a shock wave that is still visible today. A roughly spherical, expanding shock wave is visible in X-rays. The above image captures much of that filamentary and gigantic shock in visible light, spanning almost 100 light years and appearing twenty times the diameter of the full moon. As gas flies away from the detonated star, it decays and reacts with the interstellar medium, producing light in many different colors and energy bands. Remaining at the center of the Vela Supernova Remnant is a pulsar, a star as dense as nuclear matter that completely rotates more than ten times in a single second. [/color]
[color=navy]說明:[/color]
[color=dimgray]爆炸已經結束了，但其所造成的影響仍然持續著。 大約在1萬1千年前，在人類剛剛開始有歷史記載的時候， 船帆座有一顆星發生爆炸，在天空中形成一個非常明顯奇怪的亮點。 這顆星的外層撞到星際物質，由其產生的衝擊波至今仍然可見。利用X光波段，可以觀測到一個大致上呈現球形膨脹的震波。上圖是用可見光波段拍攝的，可以見到許多巨大的絲狀震波，大小約為100光年，在地球上看來，視角約是滿月的20倍。當氣體從爆炸的中心遠離時，它的亮度會減弱，並和附近的星際介質發生交互作用，產生各種顏色和波段的光。船帆座超新星爆炸遺骸的中心還存在著一顆脈衝星，它是一顆如原子般緻密的天體，一秒鐘可以自轉十次以上。 [/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
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