星系NGC 1947的线状物

2021年04月07日

Threads of NGC 1947
Image Credit: ESA/Hubble & NASA, D. Rosario; Acknowledgment: L. Shatz

Explanation: Found in far southern skies, deep within the boundaries of the constellation Dorado, NGC 1947 is some 40 million light-years away. In silhouette against starlight, obscuring lanes of cosmic dust thread across the peculiar galaxy’s bright central regions. Unlike the rotation of stars, gas, and dust tracing the arms of spiral galaxies, the motions of dust and gas don’t follow the motions of stars in NGC 1947 though. Their more complicated disconnected motion suggest this galaxy’s visible threads of dust and gas may have come from a donor galaxy, accreted by NGC 1947 during the last 3 billion years or so of the peculiar galaxy’s evolution. With spiky foreground Milky Way stars and even more distant background galaxies scattered through the frame, this sharp Hubble image spans about 25,000 light-years near the center of NGC 1947.

Tomorrow’s picture: Ginny’s close-up

星系NGC 1947的线状物
影像提供: ESA/Hubble & NASA, D. Rosario; 致谢: L. Shatz

说明: 位在高纬度南天剑鱼座内的NGC 1947，离我们约有4千万光年远。在背景星光的衬托下，这个特殊星系的不透光尘埃带，以黝黑的线状剪影之姿，横亘在明亮星系核的前方。不过，一般螺旋星系旋臂上的恒星、气体和尘埃，是同步旋绕星系核运动，而这个星系的尘埃和气体之运动，则和恒星有别。它们复杂且分离的运动，显示这个星系的线形尘埃和气体，可能是来自另一个星系，在过去30亿年的演化过程中，才受到这个特殊星系的吸积。这幅清晰的哈勃太空望远镜影像，呈现了NGC 1947中心约25,000光年的区域。影像里还散布着带星芒的银河前景恒星，以及更后方的背景星系。

明日的图片: Ginny’s close-up