charles 2009-3-23 10:54
星系M77的外圍
The Outskirts of M77
[img]http://i16.tinypic.com/2z4ckkm.jpg[/img]
影像版權與提供: Ken Crawford (Rancho Del Sol Observatory)
[color=navy]Explanation:[/color]
Face-on spiral galaxy M77 lies a mere 60 million light-years away toward the aquatic constellation Cetus. Also known as NGC 1068, its very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active galaxies. While M77 is also seen at x-ray, ultraviolet, infrared, and radio wavelengths, this visible light image highlights another remarkable aspect of the galaxy. In the picture, the data has been enhanced to show outer faint details, following spiral arms and structures that reach far beyond the galaxy's brighter central regions. Including the fainter outskirts, the galaxy's diameter is well over 100 thousand light-years at M77's estimated distance, making it larger than our own spiral Milky Way.
[color=navy]說明:[/color]
正面對著我們的螺旋星系M77位在鯨魚座內，離我們只有六千萬光年遠。M77又名為NGC 1068，在探索活躍星系核心的超大質量黑洞之過程中，天文學家已經仔細研究過它明亮的星系核。除了可見光觀測外，也曾在X射線、紫外光、紅外光及電波波段探索過M77。不過，上面這幅對比經過強化的可見光影像，讓我們見到這個星系另一個令人驚奇的面向；這個星系有接續在漩渦臂後，遠遠延伸到星系較明亮中心區外的昏暗細微構造。如果包括較昏暗的外圍區域，這個星系的直徑遠超過十萬光年，因此它要比我們的銀河系大。
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size]