Baryon loading of active galactic nucleus jets mediated by neutrons

K. Toma, F. Takahara

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


Plasmas of geometrically thick, black hole (BH) accretion flows in active galactic nuclei (AGNs) are generally collisionless for protons, and involve magnetic field turbulence. Under such conditions a fraction of protons can be accelerated stochastically and create relativistic neutrons via nuclear collisions. These neutrons can freely escape from the accretion flow and decay into protons in the dilute polar region above the rotating BH to form relativistic jets. We calculate geometric efficiencies of the neutron energy and mass injections into the polar region, and show that this process can deposit luminosity as high as Lj ~ 2 × 10-3. Mc2 and mass loading Mj ~ 6 × 10-4 M for the case of the BH mass M ~ 108 M, where M is the mass accretion rate. The terminal Lorentz factors of the jets are Γ ~ 3, and they may explain the AGN jets having low luminosities. For higher luminosity jets, which can be produced by additional energy inputs such as Poynting flux, the neutron decay still can be a dominant mass loading process, leading to, e.g., Γ ~ 50 for L j,tot ~ 3 × 10-2 Mc2.

Original languageEnglish
Article number148
JournalAstrophysical Journal
Issue number2
Publication statusPublished - 2012 Aug 1
Externally publishedYes


  • black hole physics
  • galaxies: jets
  • plasmas

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Baryon loading of active galactic nucleus jets mediated by neutrons'. Together they form a unique fingerprint.

Cite this