A new model of PeV gamma ray sources and MHD turbulence in neutron star accretion columns

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5225300

Smith, I A

In recent years, several accreting X ray binary sources have been found to emit gamma rays. This requires the acceleration of protons to energies of 10(exp 16) to 10(exp 17) eV. It was proposed that protons could be accelerated to these energies in the outer regions of a neutron star's closed magnetosphere. However, the main source of energy is near the surface of the star, where matter falling down an accretion column releases its gravitational potential energy. Herein, it is postulated that at certain times for these sources, a hot, dense, optically thick plasma pool forms in the column. Using a magnetohydrodynamic (MHD) model, a linear instability analysis shows that the top portion of this pool can become unstable to convective motions in spite of the strong magnetic field. Assuming that fully developed turbulence results, a Lighthill-like analysis was performed, and it was found that perturbations to the strength of the background magnetic field travel from the turbulent region up the column carrying energy out to the region of the energetic protons. Using simple Mixing Length Theory arguments, it was found that there may be sufficient energy transfer to explain the observed high energy gamma ray luminosities.

• Research Organization: Washington Univ., Seattle, WA (United States)
• OSTI ID: 5225300
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
DATA
DISTURBANCES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY TRANSFER
FERMIONS
FLOW MODELS
FLUID MECHANICS
GAMMA RADIATION
GRAVITATIONAL FIELDS
HADRONS
HIGH TEMPERATURE
HYDRODYNAMICS
INFORMATION
IONIZING RADIATIONS
LUMINOSITY
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
NEUTRON STARS
NUCLEONS
NUMERICAL DATA
OPTICAL PROPERTIES
PEV RANGE
PHYSICAL PROPERTIES
PLASMA
PROTONS
RADIATIONS
STARS
THEORETICAL DATA