This class implements the density structure for an alpha-accretion disk as implemented in Whitney et al. (2003), with a density given by:
Once the AlphaDisk class has been instantiated, the parameters for the density structure can be set via attributes:
>>> from hyperion.util.constants import msun, au
>>> disk = AlphaDisk()
>>> disk.mass = 2. * msun
>>> disk.rmin = 0.1 * au
>>> disk.rmax = 100 * au
The difference between FlaredDisk and AlphaDisk is that the latter includes an extra term in the density equation () but most importantly that it allows for viscous accretion luminosity, specified either via an accretion rate, or an accretion luminosity. The relation between the accretion rate and the accretion luminosity in an infinitesimal volume is:
This is equation (4) from Whitney et al. (2003). Once integrated over the whole disk, this gives a total luminosity of:
Attributes
mass | Total disk mass (g) |
rho_0 | Scale-factor for the disk density (g/cm^3) |
rmin | inner radius (cm) |
rmax | outer radius (cm) |
p | surface density power-law exponent |
beta | scaleheight power-law exponent |
h_0 | scaleheight of the disk at r_0 (cm) |
r_0 | radius at which h_0 is defined (cm) |
cylindrical_inner_rim | Whether the inner edge of the disk should be defined as a truncation |
cylindrical_outer_rim | Whether the outer edge of the disk should be defined as a truncation |
mdot | accretion rate (g/s) |
lvisc | viscous accretion luminosity (ergs/s) |
star | central star instance (needs mass and radius attributes) |
dust | dust properties (filename or dust object) |
Methods
density(grid) | Return the density grid |
midplane_cumulative_density(r) | Find the cumulative column density as a function of radius. |
vertical_cumulative_density(r, theta) | Find the cumulative column density as a function of theta. |
accretion_luminosity(grid) | Return the viscous accretion luminosity grid |
Methods (detail)
Return the density grid
Parameters : | grid : SphericalPolarGrid or CylindricalPolarGrid instance.
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Returns : | rho : np.ndarray
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Find the cumulative column density as a function of radius.
The cumulative density is measured outwards from the origin, and in the midplane.
Parameters : | r : np.ndarray
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Returns : | rho : np.ndarray
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Find the cumulative column density as a function of theta.
Parameters : | r : float
theta : np.ndarray
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Returns : | rho : np.ndarray
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Return the viscous accretion luminosity grid
Parameters : | grid : SphericalPolarGrid or CylindricalPolarGrid instance.
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Returns : | lvisc : np.ndarray
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