Black hole magnetosphere with small-scale flux tubes - II. Stability and dynamics

Yajie Yuan, Anatoly Spitkovsky, Roger D. Blandford, Dan R. Wilkins

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


In some Seyfert galaxies, the hard X-rays that produce fluorescent emission lines are thought to be generated in a hot corona that is compact and located at only a few gravitational radii above the supermassive black hole. We consider the possibility that this X-ray source may be powered by small-scale magnetic flux tubes attached to the accretion disc near the black hole. We use three-dimensional, time-dependent, special relativistic, force-free simulations in a simplified setting to study the dynamics of such flux tubes as they get continuously twisted by the central compact star/black hole. We find that the dynamical evolution of the flux tubes connecting the central compact object and the accretion disc is strongly influenced by the confinement of the surrounding field. Although differential rotation between the central object and the disc tends to inflate the flux tubes, strong confinement from surrounding field quenches the formation of a jet-like outflow, as the inflated flux tube becomes kink unstable and dissipates most of the extracted rotational energy relatively close to the central object. Such a process may be able to heat up the plasma and produce strong X-ray emission. We estimate the energy dissipation rate and discuss its astrophysical implications.

Original languageEnglish (US)
Pages (from-to)4114-4127
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
StatePublished - Aug 11 2019

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • black hole physics
  • instabilities
  • magnetic fields
  • relativistic processes


Dive into the research topics of 'Black hole magnetosphere with small-scale flux tubes - II. Stability and dynamics'. Together they form a unique fingerprint.

Cite this