Modelling the black hole silhouette in Sagittarius A* with ion tori

• We calculate the "observed at infinity" image and spectrum of the accretion structure in Sgr A*, by modelling it as an optically thin, constant angular momentum ion torus in hydrodynamic equilibrium. The physics we consider includes a two-temperature plasma, a toroidal magnetic field, as well as radiative cooling by bremsstrahlung, synchrotron, and inverse Compton processes. Our relativistic model has the virtue of being fully analytic and very simple, depending only on eight tunable parameters: the black hole spin and the inclination of the spin axis to our line of sight, the torus angular momentum, the polytropic index, the magnetic to total pressure ratio, the central values of density and electron temperature, and the ratio of electron to ion temperatures. The observed image and spectrum are calculated numerically using the ray-tracing code GYOTO. Our results demonstrate that the ion torus model is able to account for the main features of the accretion structure surrounding Sgr A*. RAMOWICZ M, 1978, ASTRONOMY AND ASTROPHYSICS, V63, P221 RAMOWICZ MA, 1995, ASTROPHYSICAL JOURNAL, V438, PL37 RAMOWICZ MA, 1983, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, V203, P323

Subject headings

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Keyword

black hole physics

accretion

accretion disks

Galaxy: center

advection-dominated accretion

near-infrared flares

galactic-center

x-ray

synchrotron-radiation

angular-momentum

magnetic-field

central

parsec

disks

simulations

neration instrumentation

p313

rmer cd

1991

astrophysical journal

v369

p410

Publication and Content Type

ref (subject category)

art (subject category)