Work

Steady-State Solutions for a Geometrically Thin Accretion Disk with Magnetically Driven Winds

Year: 2025

Type: article

Abstract: We present steady-state solutions for a one-dimensional, magnetically driven accretion disk wind model based on magnetohydrodynamic equations. We assume a geometrically thin, gas-pressure-dominated accretion disk, incorporating both magnetic braking and turbulent viscosity introduced by an extended alpha-viscosity prescription. Additionally, the vertical stress parameter is assumed to scale with the disk aspect ratio. We confirm that the derived solutions result in standard disk solutions when the wind is absent. We find that the mass accretion rate decreases as the disk mass falls inward, while the mass loss rate increases with radius. The disk spectrum emitted from the magnetically driven disk wind can be observed without interference from the wind medium because the wind is significantly optically thin. The spectral luminosity is proportional to $\nu ^{1/3}$ in the intermediate, multicolor-blackbody wavebands, in the absence of wind, as predicted by standard disk theory. However, in the presence of wind, it follows a different power-law dependence on frequency over the same range. A deviation from the spectral slope of $1/3$, particularly a negative spectral slope, is a clear indicator of the presence of a magnetically driven wind. We also discuss an observational strategy to test our model with multiwavelength observations.

Source: Progress of Theoretical and Experimental Physics

DOI: 10.1093/ptep/ptaf014

Authors: Mageshwaran Tamilan, Kimitake Hayasaki, Takeru K Suzuki

Institutions: Chungbuk National University, Aoyama Gakuin University, The University of Tokyo

Language: English

Topic: Astrophysical Phenomena and Observations

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $979