Features of Structure and Absorption in the Jet-Launching Region of M87
Abstract
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 Rs. 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.
- Publication:
-
Galaxies
- Pub Date:
- October 2019
- DOI:
- 10.3390/galaxies7040086
- arXiv:
- arXiv:1910.14299
- Bibcode:
- 2019Galax...7...86Z
- Keywords:
-
- galaxies: individual (M87);
- galaxies: jets;
- galaxies: active;
- radio continuum: galaxies;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted by Galaxies