天鹅星云的红外线新拍图像（图）   

M17星云（天鹅星云）

New Infrared Image of Swan Nebula

NASA's Spitzer Space Telescope has captured a new, infrared view of the choppy star-making cloud called M17, or the Swan nebula.	美国国家航空航天管理局的斯必泽太空望远镜拍下了一张新的红外线图像，图像显示了波涛汹涌的云海正在进行制造恒星的活动，该云海被称为M17星云或天鹅星云。
The cloud, located about 6,000 light-years away in the constellation Sagittarius, is dominated by a central group of massive stars — the most massive stars in the region. These central stars give off intense flows of expanding gas, which rush like rivers against dense piles of material, carving out the deep pocket at center of the picture.	天鹅星云位于大约6,000光年之外的人马座，星云中心一群质量巨大的恒星占据着支配地位，这些恒星是该天区质量最大的恒星。
Winds from the region's other massive stars push back against these oncoming rivers, creating bow shocks like those that pile up in front of speeding boats.	来自本区其他巨型恒星的星风快要顶到这些星河时，产生了犹如快速行驶的船只前面所隆起的弓形激波。
Three of these bow shocks are nestled in the upper left side of the central cavity, but are difficult to spot in this view. They are composed of compressed gas in addition to dust that glows at infrared wavelengths Spitzer can see. The smiley-shaped bow shocks curve away from the stellar winds of the central massive stars.	有三条弓形激波坐落于中心空穴的左上方，但是在该图像中不易看出。这些激波是由压缩的气体以及斯必泽太空望远镜可拍到的在红外线波段发光的尘埃组成的。笑口状的弓形激波因躲开来自中心巨型恒星的星风而发生弯曲。
In the image, dust is red, hot gas is green and white is where gas and dust intermingle. Foreground and background stars appear scattered through the image.	在该图像中，尘埃为红色，热气体为绿色，气体与尘埃混合处为白色，前景和背景中的恒星遍布整个图像。