A relatively nearby galaxy that closely resembles our own Milky Way can be seen edge-on in a new image. |
一個較近的星系酷似我們的銀河系,在一張新圖片中可以看到它的側(cè)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的觀測資料顯示:這一群恒星是一個漩渦星系,有著明亮的旋臂和棒狀的中心區(qū)域,在很大程度上類似我們的銀河系。 |
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,相似之處好象到此為止。NGC4945的中心比銀河系更加明亮,其中心很可能擁有一個超大質(zhì)量的黑洞,正在吞噬大量的物質(zhì),并且向太空噴發(fā)著巨大的能量。 |
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位于人馬座,大約在1,300萬光年之外。這張新圖像是由智利拉息拉天文臺2.2米MPG/ESO望遠鏡上搭載的寬視野攝像儀(WFI)拍攝的。 |
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. |
從地球的角度來看,星系NGC4945就象一根雪茄,但實際上該星系是圓盤狀的,其直徑是厚度的許多倍。排列成條狀的恒星以及熾熱的氣體在中心周圍盤旋。其他的漩渦星系跟銀河系一樣,呈扁平狀,在黑洞周圍通常包含一個由恒星構成的中心凸出區(qū)。 |
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. |
該望遠鏡上的特殊濾光片把高溫氣體(如:氫氣)所釋放的光色分離出去,使星系NGC4945的圖像對比非常清晰,顯示出其中的恒星形成區(qū)。 |
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. |
其他的觀測資料顯示,NGC4945擁有一個活動星系核,這意味著:跟象銀河系這樣比較平靜的星系相比,其中心的凸出區(qū)域所釋放的能量要多得多。 |
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. |
黑洞的引力將氣體和塵埃吸進來,并使吸進的物質(zhì)加速升溫,直到釋放出高能輻射,包括X射線和紫外光。包括銀河系在內(nèi)的多數(shù)大型漩渦星系,都在中心區(qū)域“招待著”一個黑洞。然而,在星系演化的這個階段,許多“黑怪”已經(jīng)不再活躍地“進食”。 |