The central engines of two unusual radio-intermediate/quiet active galactic nuclei: III Zw 2 and PG 1407+265

TL;DR

This study models the spectral energy distributions of two unusual radio-intermediate/quiet quasars, revealing the dominant emission sources and suggesting some may be high peak frequency blazars or weak line quasars.

Contribution

It applies a combined accretion disk/corona+jet model to fit multi-band SEDs of these quasars, providing insights into their emission mechanisms and classifications.

Findings

III Zw 2's optical/UV emission is from the accretion disk.

X-ray emission in III Zw 2 is jet-dominated.

PG 1407+265's IR is from dust torus, and its SED fits a high peak frequency blazar model.

Abstract

We use the accretion disk/corona+jet model to fit the multi-band spectral energy distributions (SEDs) of two unusual radio-intermediate/quiet quasars. It is found that the optical/UV emission of III Zw 2 is probably dominated by the emission from the accretion disk. The X-ray emission should be dominated by the radiation from the jet, while the contribution of the disk corona is negligible. The optical/UV component in the SED of PG 1407+265 can be well modeled as the emission from the accretion disk, while the IR component is attributed to the thermal radiation from the dust torus with an opening angle ~ 50\circ. If the X-ray continuum emission is dominated by the synchrotron emission of the jet, the source should be a "high peak frequency blazar", which obviously deviates the normal blazar sequence. The observed SED can also be fitted quite well by the accretion disk/corona model with the viscosity parameter ? = 0:5. The spectrum of the accretion disk/corona in PG 1407+265 satisfies the weak line quasar criterion suggested in Laor & Davis.