Scale-invariant radio jets and varying black hole spin

Abstract

Compact radio cores associated with relativistic jets are often observed in both active galactic nuclei and X-ray binaries. Their radiative properties follow some general scaling laws which primarily depend on their masses and accretion rates. However, it has been suggested that the black hole spin can also strongly influence the power and radio flux of these. Here, we attempt to estimate the dependency of the radio luminosity of steady jets launched by accretion disks on black hole mass, accretion rate and spin using numerical simulations. We make use of 3D GRMHD simulations of accretion disks around low-luminosity black holes in which the jet radio emission is produced by the jet sheath. We find that the radio flux increases roughly by a factor of 6 as the back hole spin increases from a~0 to a=0.98. This is comparable to the increase in accretion power with spin, meaning that the ratio between radio jet and accretion power is hardly changing. Although our jet spine power scales as expected for the Blandford-Znajek process, the dependency of jet radio luminosity on the black hole spin is somewhat weaker. Also weakly rotating black holes can produce visible radio jets. The overall scaling of the radio emission with black hole mass and accretion rate is consistent with the scale-invariant analytical models used to explain the fundamental plane of black hole activity. Spin does not introduce a significant scatter in this model. The jet-sheath model can describe well resolved accreting systems, such as SgrA* and M87, as well as the general scaling behavior of low-luminosity black holes. Hence the model should be applicable to a wide range of radio jets in sub-Eddington black holes. The black hole spin has an effect on the production of visible radio jet, but it may not be the main driver to produce visible radio jets. An extension of our findings to powerful quasars remains speculative.

10 pages, 6 figures, A&A accepted

References in corpus (7)

• Simulating the Emission and Outflows from Accretion Disks
• Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr~A*
• Variable TeV emission as a manifestation of jet formation in M87?
• Plasma diagnostic potential of 2p4f in N${}^{+}$ -- accurate wavelengths and oscillator strengths
• The Power of Imaging: Constraining the Plasma Properties of GRMHD Simulations using EHT Observations of Sgr A*
• Results from an extensive simultaneous broadband campaign on the underluminous active nucleus M81*: further evidence for mass-scaling accretion in black holes
• The Chandra Survey of Extragalactic Sources in the 3CR Catalog: X-ray Emission from Nuclei, Jets, and Hotspots in the Chandra Archival Observations

Cited by in corpus (11)

• Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
• The Size, Shape, and Scattering of Sagittarius A* at 86 GHz: First VLBI with ALMA
• Jet collimation in NGC 315 and other nearby AGN
• The Physics of Accretion Discs, Winds And Jets in Tidal Disruption Events
• Persistent Non-Gaussian Structure in the Image of Sagittarius A* at 86 GHz
• Comparison of Polarized Radiative Transfer Codes used by the EHT Collaboration
• Bhjet: a public multi-zone, steady state jet + thermal corona spectral model
• cuHARM : a new GPU accelerated GR-MHD code and its application to ADAF disks
• The Core-shift of Sagittarius A* as a Discriminant between Disk and Jet Emission Models with millimeter-VLBI
• Giant radio quasars: composite optical spectra
• What we talk about when we talk about blazars?