2018年01月23日:螺旋星系NGC 1398的缎带与珍珠-(Ribbons and Pearls of Spiral Galaxy NGC 1398)

2018年01月23日:螺旋星系NGC 1398的缎带与珍珠-(Ribbons and Pearls of Spiral Galaxy NGC 1398)

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2018-01-23 / 0 评论 / 0 阅读 / 正在检测是否收录...

2018年01月23日:螺旋星系NGC 1398的缎带与珍珠-(Ribbons and Pearls of Spiral Galaxy NGC 1398)
2018年01月23日:螺旋星系NGC 1398的缎带与珍珠-(Ribbons and Pearls of Spiral Galaxy NGC 1398)--原图下载


Image Credit: European Southern Observatory
说明: 为什么有些螺旋星系有拱心环呢?螺旋星系NGC 1398的中心,不但有一圈珍珠状的恒星、气体和尘埃,还有一道横亘过中心的恒星和气体长棒,而较外围的旋臂也形似缎带。这幅由位在智利欧南天文台帕连那天文台极大望远镜拍摄之主题影像,无比清晰的解析了这个宏伟的螺旋星系。NGC 1398的距离大约有6千5百万光年远,也就是说我们现在见到的光,大约在恐龙正从地球消失时,就离开了这个星系。这个位在天炉座方向,用小望远镜就得见的美丽星系,核心附近的环状构造,可能是恒星诞生活动造成的扩张密度波,触发源可能是此星系和另一个星系近距离重力接近,或者是由于它本身的重力不对称。

原文:

Image Credit: European Southern Observatory
Explanation: Why do some spiral galaxies have a ring around the center?Spiral galaxy NGC 1398 not only has a ring of pearly stars, gas and dust around its center, but a bar of stars and gas across its center, and spiral arms that appear like ribbons farther out. The featured image was taken with ESO's Very Large Telescope at the Paranal Observatory in Chile and resolves this grand spiral in impressive detail.NGC 1398 lies about 65 million light years distant, meaning the light we see today left this galaxy when dinosaurs were disappearing from the Earth. The photogenic galaxy is visible with a small telescope toward the constellation of the Furnace (Fornax).The ring near the center is likely an expanding density wave of star formation, caused either by a gravitational encounter with another galaxy, or by the galaxy's own gravitational asymmetries.

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