Signatures of the Disk-Jet Coupling in the Broad-line Radio Quasar 4C+74.26
Abstract
We explore the disk-jet connection in the broad-line radio quasar 4C+74.26, utilizing the results of multiwavelength monitoring of the source. The target is unique in that its radiative output at radio wavelengths is dominated by a moderately beamed nuclear jet, at optical frequencies by the accretion disk, and in the hard X-ray range by the disk corona. Our analysis reveals a correlation (local and global significance of 96% and 98% respectively) between the optical and radio bands, with the disk lagging behind the jet by 250 ± 42 days. We discuss the possible explanation for this, speculating that the observed disk and the jet flux changes are generated by magnetic fluctuations originating within the innermost parts of a truncated disk, and that the lag is related to a delayed radiative response of the disk when compared with the propagation timescale of magnetic perturbations along a relativistic outflow. This scenario is supported by re-analysis of NuSTAR data, modeled in terms of a relativistic reflection from the disk illuminated by the coronal emission, which returns an inner disk radius {R}in}/{R}ISCO}={35}-16+40. We discuss the global energetics in the system, arguing that while the accretion proceeds at the Eddington rate, with the accretion-related bolometric luminosity L bol ∼ 9 × 1046 erg s-1 ∼ 0.2L Edd, the jet total kinetic energy L j ∼ 4 × 1044 erg s-1, inferred from the dynamical modeling of the giant radio lobes in the source, constitutes only a small fraction of the available accretion power.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2018
- DOI:
- 10.3847/1538-4357/aade9c
- arXiv:
- arXiv:1805.06957
- Bibcode:
- 2018ApJ...866..132B
- Keywords:
-
- accretion;
- accretion disks;
- black hole physics;
- galaxies: active;
- quasars: individual: 4C +74.26;
- radiation mechanisms: non-thermal;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 9 pages and 6 figures, ApJ accepted