Astronomy Picture of the Day——M82：具有超星系风的星系
M82: Galaxy with a Supergalactic Wind
Image Credit: NASA, ESA, Hubble; Processing & Copyright: Daniel Nobre
Explanation: Why is the Cigar Galaxy billowing red smoke? M82, as this starburst galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas and dust, however. Evidence indicates that this gas and dust is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind. The dust particles are thought to originate in M82's interstellar medium and are actually similar in size to particles in cigar smoke. The featured photographic mosaic highlights a specific color of red light strongly emitted by ionized hydrogen gas, showing detailed filaments of this gas and dust. The filaments extend for over 10,000 light years. The 12-million light-year distant Cigar Galaxy is the brightest galaxy in the sky in infrared light, and can be seen in visible light with a small telescope towards the constellation of the Great Bear (Ursa Major).
M82：具有超星系风的星系
为什么雪茄星系会冒出滚滚红烟？M82，也就是这个著名的星暴星系，最近在经过大型旋涡星系M81附近时受到了激发。然而，这并不能完全解释这些向外扩散、发出红色辉光的尘埃和气体的来源。有证据表明，这些气体和尘埃是由许多恒星粒子风组成的，最后它们共同创造了一种星系超级风。尘埃颗粒被认为起源于M82的星际介质，其大小实际上与雪茄烟雾中的颗粒相似。这幅精彩的合成影像呈现了电离氢气发出的一种特殊红色强光，以及这些气体和尘埃的细致丝状结构，其长度超过了1万光年。距离我们1千2百万光年远的雪茄星系是红外光波段天空中最亮的星系，在可见光下、用一台小型望远镜朝向大熊座方向就能看到它。
参考文献：
https://apod.nasa.gov/apod/image/1907/M82_HubbleNobre_1824.jpg
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