费米望远镜累积12年的全天伽玛射线图

费米望远镜累积12年的全天伽玛射线图

Fermi’s 12-year All-Sky Gamma-ray Map
Image Credit: NASA, DOE, Fermi LAT Collaboration; Text: Barb Mattson (U. Maryland, NASA‘s GSFC)

Explanation: Forget X-ray vision — imagine what you could see with gamma-ray vision! The featured all-sky map shows what the universe looks like to NASA’s Fermi Gamma-ray Space Telescope. Fermi sees light with energies about a billion times what the human eye can see, and the map combines 12 years of Fermi observations. The colors represent the brightness of the gamma-ray sources, with brighter sources appearing lighter in color. The prominent stripe across the middle is the central plane of our Milky Way galaxy. Most of the red and yellow dots scattered above and below the Milky Way’s plane are very distant galaxies, while most of those within the plane are nearby pulsars. The blue background that fills the image is the diffuse glow of gamma-rays from distant sources that are too dim to be detected individually. Some gamma-ray sources remain unidentified and topics of research — currently no one knows what they are.

Tomorrow’s picture: a dark tower

费米望远镜累积12年的全天伽玛射线图
影像提供: NASA, DOE, Fermi LAT Collaboration; 文稿提供: Barb Mattson (U. Maryland, NASA‘s GSFC)

说明: 忘掉如何拥有X射线视觉吧；不过倒是可以想想，如果有伽玛射线视觉，会看到什么？这张主题全天图，展示了宇宙在美国国家航空航天局（NASA）费米伽玛射线太空望远镜里的样貌。费米望远镜侦测到的光之能量，约为人眼所见光的10亿倍，而这张全天图整合了费米望远镜12年的观测数据。图上的颜色代表伽玛射线源的亮度，亮度越高的源，颜色越浅。全天图中央的醒目条纹，则是我们银河系的中央盘面。散布在银河盘面上方及下方的红色和黄色光点，大多数是非常遥远的星系，而在银河盘面内的光点，则大多是邻近的脉冲星/波霎。这幅全天图里无所不在的蓝色背景，是过于微弱、难以侦测到的遥远伽玛射线源所发出的弥散辉光。图中有部分的伽玛射线源尚待辨认，至今没有人知道它们是什么，故它们仍然是当前研究的课题。

明日的图片: a dark tower