jaxtronomy.LensModel.MultiPlane package

Submodules

jaxtronomy.LensModel.MultiPlane.decoupled_multi_plane module

class MultiPlaneDecoupled(z_source, lens_model_list, lens_redshift_list, cosmo=None, observed_convention_index=None, ignore_observed_positions=False, z_source_convention=None, z_lens_convention=None, cosmo_interp=False, z_interp_stop=None, num_z_interp=100, profile_kwargs_list=None, distance_ratio_sampling=False, cosmology_sampling=False, cosmology_model='FlatLambdaCDM', x0_interp=None, y0_interp=None, alpha_x_interp_foreground=None, alpha_y_interp_foreground=None, alpha_x_interp_background=None, alpha_y_interp_background=None, z_split=None)

Bases: MultiPlane

__init__(z_source, lens_model_list, lens_redshift_list, cosmo=None, observed_convention_index=None, ignore_observed_positions=False, z_source_convention=None, z_lens_convention=None, cosmo_interp=False, z_interp_stop=None, num_z_interp=100, profile_kwargs_list=None, distance_ratio_sampling=False, cosmology_sampling=False, cosmology_model='FlatLambdaCDM', x0_interp=None, y0_interp=None, alpha_x_interp_foreground=None, alpha_y_interp_foreground=None, alpha_x_interp_background=None, alpha_y_interp_background=None, z_split=None)

A class for multiplane lensing in which the deflection angles at certain coordinates are fixed through user-specified interpolation functions. These functions return fixed deflection angles that effectively decouple deflections by a group of deflectors at redshift Z from deflections produced by halos at redshift< Z.

This class breaks the recursive nature of the multi-plane lens equation, and can significantly speed up computations with a large number of line-of-sight halos.

Parameters:

• lens_model_list – list of lens model strings

• lens_redshift_list – list of floats with redshifts of the lens models indicated in lens_model_list

• z_source_convention – float, redshift of a source to define the reduced deflection angles of the lens models. If None, ‘z_source’ is used.

• cosmo – instance of astropy.cosmology

• profile_kwargs_list – list of dicts, keyword arguments used to initialize profile classes in the same order of the lens_model_list. If any of the profile_kwargs are None, then that profile will be initialized using default settings.

• x0_interp – a function that maps an angular coordinate on the sky to the x coordinate of a physical position [Mpc] at the first lens plane

• y0_interp – same as x0_interp, but returns the y coordinate in Mpc

• alpha_x_interp_list – a list of functions that take as input angular coordinates (x, y) and returns the x-component of the deflection angle at each coorindate

• alpha_y_interp_list – same as alpha_x_interp_list, but returns the y-component of the deflection angle at (x,y)

• z_interp_list – a list of redshifts corresponding to the alpha_x_interp_list and alpha_y_interp_list entries

geo_shapiro_delay(**kwargs)

Geometric and Shapiro (gravitational) light travel time relative to a straight path through the coordinate (0,0) Negative sign means earlier arrival time.

Parameters:

• theta_x – angle in x-direction on the image

• theta_y – angle in y-direction on the image

• kwargs_lens – lens model keyword argument list

• check_convention – boolean, if True goes through the lens model list and checks whether the positional conventions are satisfied.

Returns:

geometric delay, gravitational delay [days]

ray_shooting_partial_comoving(*args, **kwargs)

Ray-tracing through parts of the cone, starting with (x,y) in angular units as seen on the sky without lensing and angles (alpha_x, alpha_y) as seen at redshift z_start and then backwards to redshift z_stop.

Parameters:

• theta_x – angular position on the sky [arcsec]

• theta_y – angular position on the sky [arcsec]

• alpha_x – ray angle at z_start [arcsec]

• alpha_y – ray angle at z_start [arcsec]

• z_start – redshift of start of computation

• z_stop – redshift where output is computed

• kwargs_lens – lens model keyword argument list

• include_z_start – bool, if True, includes the computation of the deflection angle at the same redshift as the start of the ray-tracing. ATTENTION: deflection angles at the same redshift as z_stop will be computed always! This can lead to duplications in the computation of deflection angles.

• T_ij_start – transverse angular distance between the starting redshift to the first lens plane to follow. If not set, will compute the distance each time this function gets executed.

• T_ij_end – transverse angular distance between the last lens plane being computed and z_end. If not set, will compute the distance each time this function gets executed.

• check_convention – flag to check the image position convention (leave this alone)

Returns:

angular position and angles at redshift z_stop

ray_shooting(theta_x, theta_y, kwargs_lens, *args, **kwargs)

Ray-shooting through the lens volume with fixed deflection angles at certain lens planes passed through the alpha_x_interp/alpha_y_interp lists. Starts with (x,y) co-moving distance passed through the x0_interp and y0_interp functions, then starts multi-plane ray-tracing through all subsequent lens planes.

Parameters:

• theta_x – angular coordinate on the sky

• theta_y – angular coordinate on the sky

• kwargs_lens – keyword arguments for the main deflector

Returns:

coordinates on the source plane

alpha(theta_x, theta_y, kwargs_lens, *args, **kwargs)

Reduced deflection angle.

Parameters:

• theta_x – angle in x-direction

• theta_y – angle in y-direction

• kwargs_lens – lens model kwargs

Returns:

deflection angles in x and y directions

hessian(theta_x, theta_y, kwargs_lens, diff=1e-08, *args, **kwargs)

Computes the hessian components f_xx, f_yy, f_xy from f_x and f_y with numerical differentiation.

Parameters:

• theta_x (numpy array) – x-position (preferentially arcsec)

• theta_y (numpy array) – y-position (preferentially arcsec)

• kwargs_lens – list of keyword arguments of lens model parameters matching the lens model classes

• diff – numerical differential step (float)

Returns:

f_xx, f_xy, f_yx, f_yy

Module contents