星系NGC 4945的这张图片是从侧面拍到的。科学家们认为,该星系在很大程度上跟银河系相似,只是它的中心更为明亮,而且其中心拥有一个超大质量的黑洞。活跃的恒星形成区在图像中显示为明亮的粉红色。
A relatively nearby galaxy that closely resembles our own Milky Way can be seen edge-on in a new image. | 一个较近的星系酷似我们的银河系,在一张新图片中可以看到它的侧面。 |
Observations of the galaxy, NGC 4945, suggest that this hive of stars is a spiral galaxy much like our own, with swirling, luminous arms and a bar-shaped central region. | 星系NGC4945的观测资料显示:这一群恒星是一个漩涡星系,有着明亮的旋臂和棒状的中心区域,在很大程度上类似我们的银河系。 |
But that's where the similarity seems to end: NGC 4945 has a brighter center than the Milky Way; the look-alike's center likely harbors a supermassive black hole that is devouring reams of matter and blasting energy out into space. | 然而,相似之处好象到此为止。NGC4945的中心比银河系更加明亮,其中心很可能拥有一个超大质量的黑洞,正在吞噬大量的物质,并且向太空喷发着巨大的能量。 |
The new portrait of NGC 4945, which lies some 13 million light-years away in the constellation of Centaurus, was taken by the Wide Field Imager (WFI) instrument at the 2.2-metre MPG/ESO telescope at the La Silla Observatory in Chile. | NGC4945位于人马座,大约在1,300万光年之外。这张新图像是由智利拉息拉天文台2.2米MPG/ESO望远镜上搭载的宽视野摄像仪(WFI)拍摄的。 |
NGC 4945 appears cigar-shaped from our perspective on Earth, but the galaxy is actually a disc many times wider than it is thick, with bands of stars and glowing gas spiraling around its center. Other spiral galaxies, like ours, are similarly flattened and typically contain a central bulge of stars around a black hole. | 从地球的角度来看,星系NGC4945就象一根雪茄,但实际上该星系是圆盘状的,其直径是厚度的许多倍。排列成条状的恒星以及炽热的气体在中心周围盘旋。其他的漩涡星系跟银河系一样,呈扁平状,在黑洞周围通常包含一个由恒星构成的中心凸出区。 |
Special filters on the telescope isolate the color of light emitted by heated gases such as hydrogen, showing sharp contrasts in NGC 4945 that indicate areas of star formation. | 该望远镜上的特殊滤光片把高温气体(如:氢气)所释放的光色分离出去,使星系NGC4945的图像对比非常清晰,显示出其中的恒星形成区。 |
Other observations have revealed that NGC 4945 has an active galactic nucleus, meaning its central bulge emits far more energy than calmer galaxies like the Milky Way. | 其他的观测资料显示,NGC4945拥有一个活动星系核,这意味着:跟象银河系这样比较平静的星系相比,其中心的凸出区域所释放的能量要多得多。 |
Black holes gravitationally draw gas and dust into them, accelerating and heating this attracted matter until it emits high-energy radiation, including X-rays and ultraviolet light. Most large, spiral galaxies, including the Milky Way, host a black hole in their centers, though many of these dark monsters no longer actively "feed" at this stage in galactic development. | 黑洞的引力将气体和尘埃吸进来,并使吸进的物质加速升温,直到释放出高能辐射,包括X射线和紫外光。包括银河系在内的多数大型漩涡星系,都在中心区域“招待着”一个黑洞。然而,在星系演化的这个阶段,许多“黑怪”已经不再活跃地“进食”。 |