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银河战争:M81和M82

(原标题: Galaxy Wars: M81 and M82)

2023-01-20

浏览次数: 15

中心附近的两个主要星系离我们很远,距离北方的大熊星座1200万光年。右边,有着巨大旋臂和明亮黄色核心的是螺旋星系M81。M81也被称为波德星系,跨度约10万光年。左边是雪茄形状的不规则星系M82。这两颗行星已经在引力之战中僵持了十亿年。在一系列的宇宙近距离接触中,来自每个星系的引力都深刻地影响着另一个星系。它们的最后一次旋转持续了大约1亿年,可能在M81周围掀起了密度波,导致M81螺旋臂的丰富。M82留下了激烈的恒星形成区域和碰撞的气体云,能量如此之大,以至于星系发出x射线。在接下来的几十亿年里,它们持续的引力接触将导致合并,而一个星系将保留下来。这个星系外的场景还包括M81星系群的其他成员,NGC 3077在大螺旋星系的下方和右侧,NGC 2976在画面的右上方。在奥地利阿尔卑斯山漆黑的夜空下拍摄的这张广角图像的前景充满了一体化的通量星云。那些暗淡的尘埃星际云反射了我们银河系平面上方的星光。

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The two dominant galaxies near center are far far away, 12 million light-years distant toward the northern constellation of the Great Bear. On the right, with grand spiral arms and bright yellow core is spiral galaxy M81. Also known as Bode's galaxy, M81 spans some 100,000 light-years. On the left is cigar-shaped irregular galaxy M82. The pair have been locked in gravitational combat for a billion years. Gravity from each galaxy has profoundly affected the other during a series of cosmic close encounters. Their last go-round lasted about 100 million years and likely raised density waves rippling around M81, resulting in the richness of M81's spiral arms. M82 was left with violent star forming regions and colliding gas clouds so energetic that the galaxy glows in X-rays. In the next few billion years, their continuing gravitational encounters will result in a merger, and a single galaxy will remain. This extragalactic scenario also includes other members of the interacting M81 galaxy group with NGC 3077 below and right of the large spiral, and NGC 2976 at upper right in the frame. Captured under dark night skies in the Austrian Alps, the foreground of the wide-field image is filled with integrated flux nebulae. Those faint, dusty interstellar clouds reflect starlight above the plane of our own Milky Way galaxy.

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