class autogalaxy.profiles.mass_profiles.SphSersicRadialGradient(centre: Tuple[float, float] = (0.0, 0.0), intensity: float = 0.1, effective_radius: float = 0.6, sersic_index: float = 0.6, mass_to_light_ratio: float = 1.0, mass_to_light_gradient: float = 0.0)
__init__(centre: Tuple[float, float] = (0.0, 0.0), intensity: float = 0.1, effective_radius: float = 0.6, sersic_index: float = 0.6, mass_to_light_ratio: float = 1.0, mass_to_light_gradient: float = 0.0)

Setup a Sersic mass and light profiles.

  • centre – The (y,x) arc-second coordinates of the profile centre.
  • intensity – Overall flux intensity normalisation in the light profiles (electrons per second).
  • effective_radius – The circular radius containing half the light of this profile.
  • sersic_index – Controls the concentration of the of the profile (lower value -> less concentrated, higher value -> more concentrated).
  • mass_to_light_ratio – The mass-to-light ratio of the light profile.
  • mass_to_light_gradient – The mass-to-light radial gradient.


__init__(centre, float] = (0.0, 0.0), …) Setup a Sersic mass and light profiles.
caustics_from(grid[, pixel_scale])
convergence_1d_from(grid, Grid1D, …)
convergence_2d_from(grid, …) Calculate the projected convergence at a given set of arc-second gridded coordinates.
convergence_2d_via_gaussians_from(grid, …) Calculate the projected convergence at a given set of arc-second gridded coordinates.
convergence_func_gaussian(grid_radii, sigma, …)
convergence_via_hessian_from(grid[, buffer])
convergence_via_jacobian_from(grid[, jacobian])
cos_and_sin_to_x_axis() Determine the sin and cosine of the angle between the profile’s ellipse and the positive x-axis, counter-clockwise.
critical_curves_from(grid[, pixel_scale])
deflection_func(u, y, x, npow, axis_ratio, …)
deflections_2d_from(grid, …)
deflections_2d_via_integrator_from(grid, …) Calculate the deflection angles at a given set of arc-second gridded coordinates.
density_between_circular_annuli(…) Calculate the mass between two circular annuli and compute the density by dividing by the annuli surface area.
einstein_mass_angular_from(grid[, pixel_scale])
einstein_radius_from(grid[, pixel_scale])
eta(p) see Eq.(6) of 1906.00263
eta_u(u, coordinates)
extract_attribute(cls, attr_name) Returns an attribute of a class and its children profiles in the the galaxy as a ValueIrregular or Grid2DIrregular object.
from_axis_ratio_and_phi(centre, …)
grid_angle_to_profile(grid_thetas) The angle between each angle theta on the grid and the profile, in radians.
grid_to_eccentric_radii(grid) Convert a grid of (y,x) coordinates to an eccentric radius, which is (1.0/axis_ratio) * elliptical radius and used to define light profile half-light radii using circular radii.
grid_to_elliptical_radii(grid) Convert a grid of (y,x) coordinates to an elliptical radius.
grid_to_grid_cartesian(grid, radius) Convert a grid of (y,x) coordinates with their specified circular radii to their original (y,x) Cartesian coordinates.
grid_to_grid_radii(grid) Convert a grid of (y, x) coordinates to a grid of their circular radii.
hessian_from(grid[, buffer, deflections_func])
image_2d_via_radii_from(radius) Returns the intensity of the profile at a given radius.
kesi(p) see Eq.(6) of 1906.08263
magnification_via_hessian_from(grid[, …])
mass_angular_within_circle(radius) Integrate the mass profiles’s convergence profile to compute the total mass within a circle of specified radius.
mass_integral(x) Routine to integrate an elliptical light profiles - set axis ratio to 1 to compute the luminosity within a circle
normalization_via_mass_angular_from(…[, …])
potential_1d_from(grid, Grid1D, …)
potential_2d_from(grid, …)
potential_func(u, y, x)
radial_caustic_from(grid[, pixel_scale])
radial_critical_curve_from(grid[, pixel_scale])
radial_eigen_value_from(grid[, jacobian])
rotate_grid_from_reference_frame(grid) Rotate a grid of (y,x) coordinates which have been transformed to the elliptical reference frame of a profile back to the original unrotated coordinate grid reference frame.
shear_via_hessian_from(grid[, buffer])
shear_via_jacobian_from(grid[, jacobian])
shear_yx_via_hessian_from(grid[, buffer])
shear_yx_via_jacobian_from(grid[, jacobian])
tangential_caustic_from(grid[, pixel_scale])
tangential_critical_curve_from(grid[, …])
tangential_eigen_value_from(grid[, jacobian])
transform_grid_from_reference_frame(grid) Transform a grid of (y,x) coordinates from the reference frame of the profile to the original observer reference frame, including a rotation to its original orientation and a translation from the profile’s centre.
transform_grid_to_reference_frame(grid) Transform a grid of (y,x) coordinates to the reference frame of the profile, including a translation to its centre and a rotation to it orientation.
zeta_from(grid, amps, sigmas, axis_ratio) The key part to compute the deflection angle of each Gaussian.


average_convergence_of_1_radius The radius a critical curve forms for this mass profile, e.g.
elliptical_effective_radius The effective_radius of a Sersic light profile is defined as the circular effective radius.
sersic_constant A parameter derived from Sersic index which ensures that effective radius contains 50% of the profile’s total integrated light.