Copyright:Fabian Neyer
原文:
A big, bright, beautiful spiral, Messier 106 is at the center of this galaxy filled cosmic vista. The two degree wide telescopic field of view looks toward the well-trained constellation Canes Venatici, near the handle of the Big Dipper. Also known as NGC 4258, M106 is about 80,000 light-years across and 23.5 million light-years away, the largest member of the Canes II galaxy group. For a far away galaxy, the distance to M106 is well-known in part because it can be directly measured by tracking this galaxy’s remarkable maser, or microwave laser emission. Very rare but naturally occuring, the maser emission is produced by water molecules in molecular clouds orbiting its active galactic nucleus. Another prominent spiral galaxy on the scene, viewed nearly edge-on, is NGC 4217 below and right of M106. The distance to NGC 4217 is much less well-known, estimated to be about 60 million light-years.
中文翻譯:
在這個壯觀的宇宙景觀中，佔據中央的是明亮、美麗的螺旋星系Messier 106。這個兩度寬的望遠鏡視野朝向已知的星座犬座，靠近大熊座的把手。M106，又名NGC 4258，直徑約80,000光年，距離地球約23.5百萬光年，是犬座II星系團中最大的成員。儘管距離遙遠，M106的距離因其特殊的微波激光（maser）發射而得以直接測量。這種微波激光是由圍繞其活躍星系核的分子雲中的水分子自然產生的，非常罕見。畫面中還可以看到另一個螺旋星系NGC 4217，幾乎是側面觀察，位於M106的下方和右側。NGC 4217的距離則不太確定，估計約為6000萬光年。
#Messier106 #NGC4258 #犬座 #螺旋星系 #宇宙探索 #星際美景 #天文學 #M106 #NGC4217 #MilkyWay #GalaxyGroup
來源:NASA每日圖片
