另眼系列之不同波段的银河
己经把原来的图片换下，换成红外波段的银河。The center of our Milky Way Galaxy is located in the constellation of Sagittarius. In visible light the lion's share of stars are hidden behind thick clouds of dust. This obscuring dust becomes increasingly transparent at infrared wavelengths. This 2MASS image, covering a field roughly 10 x 8 degrees (about the area of your fist held out at arm's length) reveals multitudes of otherwise hidden stars, penetrating all the way to the central star cluster of the Galaxy.
This central core, seen in the upper left portion of the enlarged image, is about 25,000 light years away and is thought to harbor a supermassive black hole. The reddening of the stars here and along the Galactic Plane is due to scattering by the dust; it is the same process by which the sun appears to redden as it sets. The densest fields of dust still show up in this mosaic. Also evident are several nebulae to the lower right, including the Cat's Paw Nebula. The 2MASS analysis software has identified and measured the properties of almost 10 million stars in this spectacular field alone.
Image credits: 2MASS/G. Kopan, R. Hurt
来源:http://coolcosmos.ipac.caltech.e ... galplane/index.html
http://www.ipac.caltech.edu/2mass/gallery/showcase/galcen/index.html
^-^为方便大家打开阅读就不贴大图了，如果想看大图可以下载附件。注:分卷压缩，全部下载后才能解压。
[ 本帖最后由 寻找拉玛 于 2008-2-15 16:15 编辑 ] 来源:http://coolcosmos.ipac.caltech.edu/image_galleries/legacy/2m_allsky_stars/index.html
http://www.ipac.caltech.edu/2mass/gallery/showcase/allsky_stars/index.html
This panoramic view encompasses the entire sky as seen by Two Micron All-Sky Survey. The measured brightnesses of half a billion stars (points) have been combined into colors representing three distinct wavelengths of infrared light: blue at 1.2 microns, green at 1.6 microns microns, and red at 2.2 microns.
This image is centered on the core of our own Milky Way galaxy, toward the constellation of Sagittarius. The reddish stars seemingly hovering in the middle of the Milky Way's disc -- many of them never observed before -- trace the densest dust clouds in our galaxy. The two faint smudges seen in the lower right quadrant are our neighboring galaxies, the Small and Large Magellanic Clouds.
Image credits: 2MASS/J. Carpenter, T. H. Jarrett, & R. Hurt
译文来源:http://www.cpus.gov.cn/zlg/yuzhou/zth1.htm
在这张巡天图里，我们银河系鼓胀的核心、黝黑的尘埃带、纤薄的盘面以及临近的星系都清晰可见。不过，这张数字影像并不是传统的红外光照片，而是根据2微米巡天计划(2MASS)的数据所建构出来的，像素的明暗代表的是这个天区恒星数量的多寡。2微米巡天计划是一项在地面进行的观测，它在2001年完成了全天空的观测任务，总共编录了大约二亿五千颗恒星。 2MASS的全天图的亮度和颜色，是根据在三个近红外光波段所测得的恒星数而给定的。在下面这张经过剪裁的影像里，恒星拥挤的银河核心区位在影像的左上方，而银河系明亮的盘面水平穿过银核。就是在穿透力较强的近红外光波段，星际尘埃云密集的区域还是不透光，使得尘埃带所在区域的恒星数量变得很少，因此这些区域也很阴暗。影像右下方的迷蒙星系是我们银河系的近邻——大、小麦哲伦星云，而散布在影像各处的点状亮斑，是由银河系四周恒星很密集的球状星团所造成。
如果想看大图可以点击:http://www.ipac.caltech.edu/2mass/gallery/showcase/allsky_stars/Allsky-Stars_med.jpg
^-^为方便大家打开阅读就不贴大图了，如果想看大图可以下载附件。注:分卷压缩，全部下载后才能解压。
[ 本帖最后由 寻找拉玛 于 2008-2-15 17:22 编辑 ] 来源:http://gallery.spitzer.caltech.edu/Imagegallery/image.php?image_name=sig05-025
A GLIMPSE of the Milky Way
In visible light, the bulk of our Milky Way galaxy's stars are eclipsed behind thick clouds of galactic dust and gas. But to the infrared eyes of NASA's Spitzer Space Telescope, distant stars and dust clouds shine with unparalleled clarity and color.
In this panoramic image (center row) from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) project, a plethora of stellar activity in the Milky Way's galactic plane, reaching to the far side of our galaxy, is exposed. This image spans 9 degrees of sky (approximately the width of a fist held out at arm's length).
The red clouds indicate the presence of large organic molecules (mixed with the dust), which have been illuminated by nearby star formation. The patches of black are dense obscuring dust clouds impenetrable by even Spitzer's super-sensitive infrared eyes. Bright arcs of white throughout the image are massive stellar incubators.
With over 160 megapixels, the full detail in this panorama cannot be appreciated without zooming in to various areas of interest (top and bottom rows). Bubbles, or holes, in the red clouds are formed by the powerful outflows from massive groups of forming stars. Wisps of green indicate the presence of hot hydrogen gas. Star clusters can also be seen as the groupings of blue, yellow, and green specks inside some of the red nebulae, or star-forming clouds. In contrast to the plentiful examples of stellar youth in this montage, Spitzer also sees an object called a planetary nebula (top row, middle). Such nebulae are the final gasp of dying stars like our sun, whose outer layers are blown into space, leaving a burnt -out core of a star, called a white dwarf, behind.
Although this panoramic image captures a large range of the galaxy, it represents only 7.5 percent of the primary GLIMPSE survey, which will image most of the star formation regions in our galaxy.
The infrared images were captured with the Spitzer's Infrared Array Camera (IRAC). The pictures are 4-channel false-color composites, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red).
[ 本帖最后由 寻找拉玛 于 2008-2-15 17:06 编辑 ] 来源:http://cse.ssl.berkeley.edu/bmendez/ay10/2002/notes/lec16.html
^-^为方便大家打开阅读就不贴大图了，如果想看大图可以下载附件。注:分卷压缩，全部下载后才能解压。
[ 本帖最后由 寻找拉玛 于 2008-2-25 13:49 编辑 ] 好美的银河~宇宙太浩翰了~~~~~
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