Unveiling the small-scale jets in the rapidly growing supermassive black hole IZw1

Autor: Yang, Xiaolong, Yao, Su, Gallo, Luigi C., Yang, Jun, Ho, Luis C., Gu, Minfeng, Baan, Willem A., Svoboda, Jiri, Wang, Ran, Liu, Xiang, Hong, Xiaoyu, Wu, Xue-Bing, Zhao, Wei
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
Popis: Accretion of black holes at near-Eddington or super-Eddington rates is the most powerful episode that drives black hole growth, and it may work in several types of objects. However, the physics of accretion and jet-disc coupling in such a state remains unclear, mainly because the associated jets are not easily detectable due to the extremely weak emission or possibly episodic nature of the jets. Only a few near/super-Eddington systems have demonstrated radio activity, and it remains unclear whether there is a jet and what are their properties, in super-Eddington active galactic nuclei (AGNs) (and ultraluminous X-ray sources). The deficit is mainly due to the complex radio mixing between the origins of jets and others, such as star formation activity, photo-ionized gas, accretion disk wind, and coronal activity. In this work, we conducted high-resolution very long baseline interferometry (VLBI) observations to explore the jets in the highly accreting narrow-line Seyfert I system IZw1. Our observations successfully revealed small-scale jets (with a linear size of $\sim45$ parsec) at both 1.5 and 5 GHz, based on the high radio brightness temperature, radio morphology, and spectral index distribution. Interestingly, the lack of a flat-spectrum radio core and knotty jet structures imply episodic ejections in IZw1, which resemble the ejection process in Galactic X-ray binaries that are in the canonical very high state. The high accretion rates and jet properties in the AGN IZw1 may support the AGN/XRB analogy in the extreme state.
Comment: 19 pages, 8 figures and 4 tables, submitted to ApJ. 2nd round referee report received. comments welcome
Databáze: arXiv
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