[Paper Review] Single and binary Black Holes and their active environment

Peter L. Biermann, Mihaela Chirvasa+3 more|arXiv (Cornell University)|Nov 22, 2002

Astrophysical Phenomena and Observations32 references3 citations

TL;DR

This paper proposes that the jet-disk symbiosis model—originally developed for massive black holes—applies universally across black hole mass scales, including microquasars. It demonstrates that jet emission alone can explain observed spectra and variability, and shows that spin misalignment in binary black hole mergers leads to strong angular momentum inhibition and spin flips, preserving high final spin and enabling efficient jet formation and gravitational wave emission with spin-dependent waveforms.

ABSTRACT

In this short review we describe some of the latest endeavours to understand the activity around Black Holes. First, it has been possible to demonstrate that a large part of the electromagnetic emission observed can be interpreted as arising from the jet; this explains at once all spectral features and their variability. Second we dwell on the concept that merging galaxies naturally lead to merging Black Holes. Here we emphasize two aspects: a) the torque exerted by the binary Black Holes carves a torus like distribution out of the stellar population near to the Black Hole binary; b) We consider the last stages of the Black Hole binary merger, taking into account the angle between the spin of the primary Black Hole, and the orbital spin of the second Black Hole. We show that the loss of orbital angular momentum is very strongly spin-dependent; for large angles between the two spins the angular momentum loss is strongly inhibited, allowing spin flip of the primary Black Hole which preserves a high angular momentum relative to the maximum allowed. This ensures that both before and after the merger the accretion disk may reach to very small distances from the central Black Hole, with very high local temperatures right near the base of the jet: This is especially interesting in the case that forming the jet requires the formation of an ADAF like ring near the inner edge of the disk, as suggested by some earlier work. It also may have consequences for the initial hadronic interactions right near the base of the jet. Finally, this may also have important implications for the discovery of gravitational radiation bursts from the merger of black holes; the spin dependence needs to be taken into account.

Motivation & Objective

• To test whether the jet-disk symbiosis model, effective for massive black holes, applies to stellar-mass black holes (microquasars).
• To investigate how binary black hole mergers, especially with misaligned spins, affect angular momentum loss and final spin orientation.
• To explore the implications of spin-dependent merger dynamics for accretion disk structure, jet formation, and gravitational wave detection.
• To examine whether stellar winds from red/blue supergiants can form the observed torus in active galactic nuclei.
• To assess the impact of spin misalignment on gravitational wave templates for black hole merger detection.

Proposed method

• Modeling electromagnetic emission from microquasars using synchrotron and inverse Compton emission from relativistic jets, with shock acceleration as a key mechanism.
• Applying mass and energy conservation with scaling laws to relate microquasars to larger active galactic nuclei.
• Using numerical simulations to calculate orbital angular momentum loss during binary black hole mergers as a function of spin-orbit angle.
• Analyzing the dependence of gravitational wave emission on the angle between the primary black hole's spin and the secondary's orbital angular momentum.
• Evaluating the formation of ADAF-like structures near the inner disk edge as a precursor to jet formation.
• Comparing model predictions with CHANDRA X-ray observations of microquasars to validate the jet-disk symbiosis model.

Experimental results

Research questions

• RQ1 Can the jet-disk symbiosis model explain the full electromagnetic spectrum of microquasars with minimal disk emission?
• RQ2 How does the angle between the orbital angular momentum of a secondary black hole and the spin of the primary affect angular momentum loss during merger?
• RQ3 What are the implications of spin misalignment for the final spin state and angular momentum of the merged black hole?
• RQ4 Can stellar winds from evolved stars in dense nuclear regions form the observed torus in active galactic nuclei?
• RQ5 How does spin-dependent angular momentum loss modify the gravitational wave signal from black hole mergers, and what does this imply for detection templates?

Key findings

• The jet-disk symbiosis model successfully explains the entire electromagnetic spectrum of microquasars, with nearly all emission arising from the jet and only a minor contribution from the disk or disk corona.
• The loss of orbital angular momentum during binary black hole mergers is strongly dependent on the angle between the secondary’s orbital spin and the primary’s intrinsic spin, with misaligned configurations showing significant inhibition.
• Spin flips of the primary black hole can occur during merger, preserving a high final spin close to the maximum allowed, due to incomplete removal of orbital angular momentum.
• The high final spin ensures that accretion disks can extend to very small radii near the event horizon both before and after merger, leading to high local temperatures near the jet base.
• The presence of an ADAF-like structure near the inner disk edge may be crucial for jet formation and could influence hadronic interactions in the jet base region.
• Spin-dependent angular momentum loss must be incorporated into gravitational wave templates, as it significantly alters the waveforms of merger signals, especially in systems with large spin-orbit misalignment.