Astronomy Picture of the Day——在射电波下拍摄的银心
The Galactic Center in Radio from MeerKAT
Image Credit: MeerKAT, SARAO
Explanation: What's happening at the centerof our galaxy? It's hard to tell with optical telescopes since visible light isblocked by intervening interstellar dust. In other bands of light, though, suchas radio, the galactic center can be imaged and shows itself to be quite aninteresting and active place. The featured picture shows the inaugural image ofthe MeerKAT array of 64 radio dishes just completed in South Africa. Spanningfour times the angular size of the Moon (2 degrees), the image is impressivelyvast, deep, and detailed. Many known sources are shown in clear detail,including many with a prefix of Sgr, since the Galactic Center is in thedirection of the constellation Sagittarius. In our Galaxy's Center lies Sgr A,found here just to the right of the image center, which houses the Milky Way'scentral supermassive black hole. Other sources in the image are not as wellunderstood, including the Arc, just to the left of Sgr A, and numerousfilamentary threads. Goals for MeerKAT include searching for radio emissionfrom neutral hydrogen emitted in a much younger universe and brief but distantradio flashes.
MeerKAT在射电波下拍摄的银心
银河系的中心发生了什么？因为可见光被星际尘埃所遮挡，所以使用光学望远镜很难发现银心。然而，在其他光带，例如射电波，银心能够被拍摄成像，并显示出它是一个异常有趣且活跃的地方。这幅特征影像是刚刚在南非获取的，它是由64个射电天线组成的MeerKAT阵列拍摄的首张照片。它的角直径是月球的四倍（两度），其庞大、深邃且精细的结构令人印象深刻。因为银心位于人马座方向，所以许多已知的银心辐射源都非常清晰的呈现出来，包括许多前缀为Sgr的辐射源。我们银河系中心的人马座A（Sgr A）位于该影像中心的右侧，那里寄居着银河系中心特大质量黑洞。而影像中的其他辐射源还没有被很好地理解，包括位于Sgr A左侧的光弧和许多细丝结构。MeerKAT的目标是寻找在更年轻宇宙中释放的中性氢所辐射出的射电波，以及短暂而遥远的射电闪光。
参考文献：
https://apod.nasa.gov/apod/image/1907/GCenter_MeerKAT_5000.jpg
近期文章：
Astronomy Picture of the Day——木星上的深渊