A nearby luminous AGN sample optically selected from Hubble Space Telescope (HST)

TL;DR

This study selects a sample of 30 nearby luminous AGNs from HST data, analyzing their X-ray and radio properties to understand differences in emission mechanisms between radio-loud and radio-quiet AGNs.

Contribution

It provides a high-precision sample of luminous AGNs with multi-wavelength data, revealing the role of jet X-ray emission in RLAGN and supporting the accretion mode transition hypothesis.

Findings

Absence of certain relationships in RLAGN suggests complex physical processes.

X-ray emission from jets is significant in RLAGN.

Traditional relationships in RQAGN are consistent with previous studies.

Abstract

In this work, a nearby luminous AGN sample is selected from HST, where only sources with both X-ray emission observed by \textit{Chandra/XMM-Newton} and radio flux detected by VLA/VLBA/VLBI/MERLIN are adopted to keep high precision. We get a sample of 30 luminous AGNs finally, which consist of 11 RLAGN and 19 RQAGN. It is found that the relationship between $R_{\rm {UV}}$ and $\alpha_{\rm {ox}}$, which was firstly reported by Li & Xie (2017) in LLAGN, and other relationships are all absent in RLAGN, probably due to the complex physical process therein. Our results indicate that the X-ray emission from jet should play an important role in RLAGN and further support the transition of accretion mode between LLAGN and RLAGN. On the other hand, the traditional relationships in RQAGN, such as $\alpha_{\rm {ox}}$ and $\lambda$, $\Gamma$ and $\lambda$, are found to be well consistent with previous works.