Features of Structure and Absorption in the Jet-Launching Region of M87
by
Wei Zhao 1,2,*
, Xiaoyu Hong 1,2,3,4, Tao An 1,2, Xiaofeng Li 1,2,3,4, Xiaopeng Cheng 1,2,3 and Fang Wu 1,2
Wei Zhao 1,2,*, Xiaoyu Hong 1,2,3,4, Tao An 1,2, Xiaofeng Li 1,2,3,4, Xiaopeng Cheng 1,2,3 and Fang Wu 1,2
1
Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai 200030, China
2
Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing 210008, China
3
University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
4
ShanghaiTech University, 100 Haike Road, Pudong, Shanghai 201210, China
*
Author to whom correspondence should be addressed.
Galaxies 2019, 7(4), 86; https://doi.org/10.3390/galaxies7040086
Received: 30 September 2019 / Revised: 24 October 2019 / Accepted: 28 October 2019 / Published: 31 October 2019
M87 is one of the best available source for studying the AGN jet-launching region. To enrich our knowledge of this region, with quasi-simultaneous observations using VLBA at 22, 43 and 86 GHz, we capture the images of the radio jet in M87 on a scale within several thousand . Based on the images, we analyze the transverse jet structure and obtain the most accurate spectral-index maps of the jet in M87 so far, then for the first time, we compare the results of the two analyses and find a spatial association between the jet collimations and the local enhancement of the density of external medium in the jet-launching region. We also find the external medium is not uniform, and greatly contributes to the free-free absorption in this region. In addition, we find for the jet in M87, its temporal morphology in the launching region may be largely affected by the local, short-lived kink instability growing in itself.
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MDPI and ACS Style
Zhao, W.; Hong, X.; An, T.; Li, X.; Cheng, X.; Wu, F. Features of Structure and Absorption in the Jet-Launching Region of M87. Galaxies 2019, 7, 86.
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