Lens#

class silmaril.lens.Lens(x_deflections, y_deflections, wcs, redshift, unit='arcsec')#

Bases: object

Class representing a lensing cluster.

Parameters:

x_deflections (np.ndarray) – x-component of the deflection angles
y_deflections (np.ndarray) – y-component of the deflection angles
wcs (astropy.wcs.WCS) – WCS object for the deflection angle map
redshift (float) – redshift of the lensing cluster
unit (str, optional) – units of the deflection angles (options are “arcseconds” and “pixels”), defaults to “arcseconds”

wcs#: WCS object for the deflection angle map

redshift#: redshift of the lensing cluster

scale#: pixel scale of the deflection angle map

x_deflections#: x-component of the deflection angles

y_deflections#: y-component of the deflection angles

__init__(x_deflections, y_deflections, wcs, redshift, unit='arcsec')#

Methods

`__init__`(x_deflections, y_deflections, wcs, ...)
`caustic`(image_plane_grid, source_redshift[, ...])	Returns a list of points on the source plane corresponding to the caustic of the lensing cluster.
`convergence`(grid, source_redshift)	Computes the convergence of the lensing cluster on the given grid.
`magnification`(grid, source_redshift)	Computes the magnification of the lensing cluster on the given grid.
`magnification_line`(grid, source_redshift[, ...])	Returns a list of points in the image plane with magnification greater than a given threshold.
`trace_grid`(grid, source_redshift)	Ray trace a grid from the image plane back to the source plane at a given redshift.
`trace_points`(points, source_redshift)	Ray trace a set of points from the image plane back to the source plane at a given redshift.

caustic(image_plane_grid, source_redshift, threshold=500)#

Returns a list of points on the source plane corresponding to the caustic of the lensing cluster. The caustic is computed by ray tracing the points on the magnification line back to the source plane.

Parameters:

image_plane_grid (Grid) – image plane grid on which to compute the magnification
source_redshift (float) – redshift of the source
threshold (float, optional) – threshold used to filter magnification values, defaults to 500

Returns:

list of points on the caustic

Return type:

numpy.ndarray

convergence(grid, source_redshift)#

Computes the convergence of the lensing cluster on the given grid.

Parameters:

grid (Grid) – grid on which to compute the convergence
source_redshift (float) – redshift of the source

Returns:

2d array of convergence values

Return type:

numpy.ndarray

magnification(grid, source_redshift)#

Computes the magnification of the lensing cluster on the given grid.

Parameters:

grid (Grid) – grid on which to compute the magnification
source_redshift (float) – redshift of the source

Returns:

2d array of magnification values

Return type:

numpy.ndarray

magnification_line(grid, source_redshift, threshold=500)#

Returns a list of points in the image plane with magnification greater than a given threshold.

Parameters:

grid (Grid) – grid on which to compute the magnification
source_redshift (float) – redshift of the source
threshold (float, optional) – threshold used to filter magnification values, defaults to 500

Returns:

list of points with magnification greater than threshold

Return type:

unknown

trace_grid(grid, source_redshift)#

Ray trace a grid from the image plane back to the source plane at a given redshift.

Parameters:

grid (Grid) – grid to trace
source_redshift (float) – redshift of the source

Returns:

traced grid in meshgrid format

Return type:

tuple(numpy.ndarray,numpy.ndarray)

trace_points(points, source_redshift)#

Ray trace a set of points from the image plane back to the source plane at a given redshift.

Parameters:

points (numpy.ndarray) – list of points to trace given in world coordinates as an array of shape (n,2)
source_redshift (float) – redshift of the source

Returns:

list of traced points

Return type:

numpy.ndarray