仙女大星系周围的云气

2022年10月24日

Clouds Around Galaxy Andromeda
Image Credit & Copyright: Andrew Fryhover

Explanation: What are those red clouds surrounding the Andromeda galaxy? This galaxy, M31, is often imaged by planet Earth-based astronomers. As the nearest large spiral galaxy, it is a familiar sight with dark dust lanes, bright yellowish core, and spiral arms traced by clouds of bright blue stars. A mosaic of well-exposed broad and narrow-band image data, this deep portrait of our neighboring island universe offers strikingly unfamiliar features though, faint reddish clouds of glowing ionized hydrogen gas in the same wide field of view. Most of the ionized hydrogen clouds surely lie in the foreground of the scene, well within our Milky Way Galaxy. They are likely associated with the pervasive, dusty interstellar cirrus clouds scattered hundreds of light-years above our own galactic plane. Some of the clouds, however, occur right in the Andromeda galaxy itself, and some in M110, the small galaxy just below.

Tomorrow’s picture: jupiter moves

仙女大星系周围的云气
图像提供与版权: Andrew Fryhover

说明: 仙女大星系周围的那些泛红云气是什么？地球的天文学家经常为仙女大星系（M31）拍照。因此，作为最邻近我们的大螺旋星系，它黯黑的尘埃带、明亮的泛黄色核心、镶着明亮泛蓝星团的螺旋臂，都是我们很熟悉的景观。然而，在这幅建构自曝光良好的宽与窄波段滤镜数据的此邻居星系之深空图像里，散发暗淡泛红辐射的电离氢气云，却让图像带着我们非常不熟悉的风貌。其中大部分的电离氢气云，肯定是位于图像的前景，近在我们的银河系之内。它们很可能与分布在我们银河盘面上方数百光年之内，无所不在饱含尘埃的星际卷云有关。不过，也有部分星云就在仙女大星系里头，更有些在下方的小星系M110内。

明日的图片: jupiter moves