oscar 2009-3-21 09:56
紅外波段的大麥哲倫星系
The Large Magellanic Cloud in Infrared
[img]http://i16.tinypic.com/4bnyse1.jpg[/img]
影像提供: NASA/JPL-Caltech/M. Meixner (STScI) & the SAGE Legacy Team
[color=navy]說明: [/color]
塵埃都集中在星系內的那些地方呢？為了找出答案，一群研究人員為鄰近大麥哲倫星系內的雲氣和塵埃，拍攝了有史以來最詳盡的影像，從而組出上面這張照片。這幅由3000張個別史匹哲望遠鏡的紅外光影像所組合出來之照片，是以往任何大麥哲倫影像解析度的一千倍，內容突顯出被恆星反饋回星際介質內的物質所發出的輝光。從影像所見到的巨大雲氣和塵埃雲，可發現塵埃偏好年輕亮星附近 (明亮紅色雲氣)、均勻分佈在恆星之間 (綠色雲氣)及殼層狀包圍著年老的恆星 (小紅點)。除此之外，還有許多巨大的空洞，它們是由先前存在的大質量恆星之強大恆星風所清出來的。影像下端的淡藍色 (假色)輝光，是位在大麥哲星系棒狀核心的年老恆星共同發出來的。大麥哲倫星系是我們銀河系的衛星星系之一，大小約有七萬光年，離我們約有十六萬光年遠，位在南天的劍魚(旗魚)座內。
[color=navy]Explanation: [/color]
Where does dust collect in galaxies? To help find out, a team of researchers took the most detailed image ever of gas clouds and dust in the neighboring Large Magellanic Cloud (LMC) galaxy. The composite image, shown above, was taken by the Spitzer Space Telescope in infrared light, which highlights the natural glow of the warm materials returned to the interstellar medium by stars. The above mosaic combines 300,000 individual pointings to create a composite 1,000-times sharper than any previous LMC image. Visible are vast clouds of gas and dust, showing in graphic detail that dust prefers regions near young stars (red-tinted bright clouds), scattered unevenly between the stars (green-tinted clouds), and in shells around old stars (small red dots). Also visible are huge caverns cleared away by the energetic outflows of massive former stars. The faint blue (false-color) glow across the bottom is the combined light from the old stars in the central bar of the LMC. The LMC is a satellite galaxy to our own Milky Way Galaxy, spans about 70,000 light years, and lies about 160,000 light years away toward the southern constellation of the Swordfish (Dorado).
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size]