[Paper Review] Powerful jets from accreting black holes: evidence from the optical and infrared

D. M. Russell, R. P. Fender|UvA-DARE (University of Amsterdam)|Jan 8, 2010

Astrophysics and Cosmic Phenomena7 references3 citations

TL;DR

This paper presents observational evidence from optical and infrared (OIR) wavelengths that stellar-mass black holes in X-ray binaries produce powerful relativistic jets, with jet kinetic power often comparable to their bolometric radiative luminosity. By analyzing OIR emission from compact jets and their interactions with surrounding matter, the study constrains jet properties such as power, Lorentz factor, and energy losses, supporting a unified view of jet physics across black hole masses from stellar to supermassive systems.

ABSTRACT

A common consequence of accretion onto black holes is the formation of powerful, relativistic jets that escape the system. In the case of supermassive black holes at the centres of galaxies this has been known for decades, but for stellar-mass black holes residing within galaxies like our own, it has taken recent advances to arrive at this conclusion. Here, a review is given of the evidence that supports the existence of jets from accreting stellar-mass black holes, from observations made at optical and infrared wavelengths. In particular it is found that on occasion, jets can dominate the emission of these systems at these wavelengths. In addition, the interactions between the jets and the surrounding matter produce optical and infrared emission on large scales via thermal and non-thermal processes. The evidence, implications and applications in the context of jet physics are discussed. It is shown that many properties of the jets can be constrained from these studies, including the total kinetic power they contain. The main conclusion is that like the supermassive black holes, the jet kinetic power of accreting stellar-mass black holes is sometimes comparable to their bolometric radiative luminosity. Future studies can test ubiquities in jet properties between objects, and attempt to unify the properties of jets from all observable accreting black holes, i.e. of all masses.

Motivation & Objective

• To establish observational evidence for relativistic jets from accreting stellar-mass black holes using optical and infrared (OIR) data.
• To constrain jet properties such as kinetic power, Lorentz factor, and confinement through broadband spectral energy distributions.
• To investigate the interaction of jets with the interstellar medium (ISM) via thermal and non-thermal emission processes in OIR bands.
• To test the universality of jet properties across black hole masses by scaling results from stellar-mass black holes to supermassive black holes in AGN.
• To explore the potential of OIR polarization and fast-timing studies to probe the inner jet regions and jet formation mechanisms.

Proposed method

• Analysis of optical and infrared (OIR) spectra and light curves of black hole X-ray binaries (BHXBs) to detect and characterize compact jet emission.
• Combining OIR data with radio, X-ray, and gamma-ray observations to construct broadband spectral energy distributions (SEDs) of the jets.
• Use of spectral index measurements (e.g., α ≈ -0.7) to infer optically thin jet emission and constrain jet geometry and optical depth.
• Application of time-dependent jet modeling to study jet evolution as a function of mass accretion rate and X-ray state.
• Use of moving emission lines and bow shock structures in OIR to measure jet velocity and time-averaged jet power.
• Comparison of OIR jet properties with theoretical jet models to infer Lorentz factor, dimensions, and confinement.

Experimental results

Research questions

• RQ1 What is the origin and nature of optical and infrared emission from compact jets in stellar-mass black hole X-ray binaries?
• RQ2 How does the kinetic power of jets from stellar-mass black holes compare to their bolometric radiative luminosity?
• RQ3 To what extent do jet properties in BHXBs scale with mass accretion rate and X-ray state, and can they be unified with AGN jet properties?
• RQ4 Can OIR polarization and fast-timing measurements constrain the magnetic field configuration and energy extraction mechanisms in the inner jet region?
• RQ5 What is the role of jet-ISM interactions in producing large-scale optical and infrared emission, and how can this inform jet energy loss and composition?

Key findings

• Optical and infrared emission from compact jets in BHXBs is often optically thin, with spectral indices α ≈ -0.7, indicating synchrotron emission from relativistic electrons.
• In some cases, the kinetic power of the jet exceeds the radiative luminosity, indicating that jets can carry more energy than is radiated.
• Jet power derived from OIR bow shock nebulae provides an independent estimate of time-averaged jet power, consistent with broadband SED modeling.
• The detection of moving emission lines from precessing jets allows for direct measurement of jet velocities, supporting relativistic speeds.
• OIR observations of discrete, moving radio ejecta can be resolved to study jet propagation and deceleration in the ISM.
• Scaling of OIR jet properties from BHXBs to AGN suggests potential universality in jet physics across black hole masses.