autogalaxy.profiles.light.standard.Chameleon#

class Chameleon[source]#

Bases: LightProfile

The elliptical Chameleon light profile.

This light profile closely approximes the Elliptical Sersic light profile, by representing it as two cored elliptical isothermal profiles. This is convenient for lensing calculations, because the deflection angles of an isothermal profile can be evaluated analyticially efficiently.

Parameters:
  • centre (Tuple[float, float]) – The (y,x) arc-second coordinates of the profile centre.

  • ell_comps (Tuple[float, float]) – The first and second ellipticity components of the elliptical coordinate system.

  • intensity (float) – Overall intensity normalisation of the light profile (units are dimensionless and derived from the data the light profile’s image is compared too, which is expected to be electrons per second).

  • core_radius_0 (float) – The core size of the first elliptical cored Isothermal profile.

  • core_radius_1 (float) – The core size of the second elliptical cored Isothermal profile.

Methods

angle_to_profile_grid_from

The angle between each angle theta on the grid and the profile, in radians.

blurred_image_2d_from

Evaluate the light object's 2D image from a input 2D grid of coordinates and convolve it with a PSF.

eccentric_radii_grid_from

Convert a grid of (y,x) coordinates to an eccentric radius: :math: axis_ratio^0.5 (x^2 + (y^2/q))^0.5

elliptical_radii_grid_from

Convert a grid of (y,x) coordinates to their elliptical radii values: :math: (x^2 + (y^2/q))^0.5

has

Does this instance have an attribute which is of type cls?

image_1d_from

Returns the light profile's 1D image from a grid of Cartesian coordinates, which may have been transformed using the light profile's geometry.

image_2d_from

Returns the Chameleon light profile's 2D image from a 2D grid of Cartesian (y,x) coordinates.

image_2d_via_radii_from

Returns the 2D image of the Sersic light profile from a grid of coordinates which are the radial distances of each coordinate from the its centre.

luminosity_integral

Routine to integrate the luminosity of an elliptical light profile.

luminosity_within_circle_from

Integrate the light profile to compute the total luminosity within a circle of specified radius.

padded_image_2d_from

Evaluate the light object's 2D image from a input 2D grid of padded coordinates, where this padding is sufficient to encapsulate all surrounding pixels that will blur light into the original image given the 2D shape of the PSF's kernel.

radial_grid_from

Convert a grid of (y, x) coordinates, to their radial distances from the profile centre (e.g. :math: r = x**2 + y**2).

rotated_grid_from_reference_frame_from

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.

transformed_from_reference_frame_grid_from

Transform a grid of (y,x) coordinates from the reference frame of the profile to the original observer reference frame.

transformed_to_reference_frame_grid_from

Transform a grid of (y,x) coordinates to the reference frame of the profile.

unmasked_blurred_image_2d_from

Evaluate the light object's 2D image from a input 2D grid of coordinates and convolve it with a PSF, using a grid which is not masked.

visibilities_from

Evaluate the light object's 2D image from a input 2D grid of coordinates and transform this to an array of visibilities using a autoarray.operators.transformer.Transformer object and therefore a Fourier Transform.

Attributes

angle

The position angle in degrees of the major-axis of the ellipse defined by profile, defined counter clockwise from the positive x-axis (0.0 > angle > 180.0).

angle_radians

The position angle in radians of the major-axis of the ellipse defined by profile, defined counter clockwise from the positive x-axis (0.0 > angle > 2pi).

axis_ratio

The elliptical isothermal mass profile deflection angles break down for perfectly spherical systems where axis_ratio=1.0, thus we remove these solutions.

coefficient_tag

half_light_radius

property axis_ratio: float#

The elliptical isothermal mass profile deflection angles break down for perfectly spherical systems where axis_ratio=1.0, thus we remove these solutions.

image_2d_via_radii_from(grid_radii)[source]#

Returns the 2D image of the Sersic light profile from a grid of coordinates which are the radial distances of each coordinate from the its centre.

Parameters:

grid_radii (ndarray) – The radial distances from the centre of the profile, for each coordinate on the grid.

Return type:

ndarray

image_2d_from(grid, operated_only=None, **kwargs)[source]#

Returns the Chameleon light profile’s 2D image from a 2D grid of Cartesian (y,x) coordinates.

If the coordinates have not been transformed to the profile’s geometry (e.g. translated to the profile centre), this is performed automatically.

Parameters:

grid (Union[ndarray, Grid2D, Grid2DIrregular]) – The 2D (y, x) coordinates in the original reference frame of the grid.

Returns:

The image of the Chameleon evaluated at every (y,x) coordinate on the transformed grid.

Return type:

image