Observational Signatures of Mass-Loading in Jets Launched by Rotating Black Holes

Abstract

It is widely believed that relativistic jets in X-ray binaries and active-galactic nuclei are powered by the rotational energy of black holes. This idea is supported by general-relativistic magnetohydrodynamic (GRMHD) simulations of accreting black holes, which demonstrate efficient energy extraction via the Blandford-Znajek mechanism. However, due to uncertainties in the physics of mass-loading, and the failure of GRMHD numerical schemes in the highly-magnetized funnel region, the matter content of the jet remains poorly constrained. We investigate the observational signatures of mass-loading in the funnel by performing general-relativistic radiative transfer calculations on a range of 3D GRMHD simulations of accreting black holes. We find significant observational differences between cases in which the funnel is empty and cases where the funnel is filled with plasma, particularly in the optical and X-ray bands. In the context of Sgr A*, current spectral data constrains the jet filling only if the black hole is rapidly rotating with $a\gtrsim 0.9$. In this case, the limits on the infrared flux disfavour a strong contribution from material in the funnel. We comment on the implications of our models for interpreting future Event Horizon Telescope observations. We also scale our models to stellar-mass black holes, and discuss their applicability to the low-luminosity state in X-ray binaries.

13 pages, 11 figures, extended and clarified aspects of the discussion section, accepted for publication in ApJ

References in corpus (15)

• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Advection-Dominated Accretion and the Black Hole Event Horizon
• Stability of Relativistic Jets from Rotating, Accreting Black Holes via Fully Three-Dimensional Magnetohydrodynamic Simulations
• Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr~A*
• The Disc-Jet Symbiosis Emerges: Modeling the Emission of Sagittarius A* with Electron Thermodynamics
• Variable TeV emission as a manifestation of jet formation in M87?
• The Power of Imaging: Constraining the Plasma Properties of GRMHD Simulations using EHT Observations of Sgr A*
• Plasma diagnostic potential of 2p4f in N${}^{+}$ -- accurate wavelengths and oscillator strengths
• A jet model for Galactic black-hole X-ray sources: Some constraining correlations
• A Model for Emission from Jets in X-ray Binaries: Consequences of a Single Acceleration Episode
• The Radiative Efficiency and Spectra of Slowly Accreting Black Holes from Two-Temperature GRRMHD Simulations
• A disc corona-jet model for the radio/X-ray correlation in black hole X-ray binaries
• Time-Dependent Synchrotron and Compton Spectra from Jets of Microquasars
• X-ray spectra of hot accretion flows
• Effects of Spin on High-Energy Radiation from Accreting Black Holes

Cited by in corpus (3)

• No Need for an Extreme Jet Energy in the Black-Hole X-Ray Binary MAXI J1348--630
• Matter density distribution of general relativistic highly magnetized jets driven by black holes
• A simple analytical model of magnetic jets