Source code for lenstronomy.PointSource.Types.lensed_position

import numpy as np
from lenstronomy.PointSource.Types.base_ps import PSBase, _expand_to_array

__all__ = ['LensedPositions']


[docs]class LensedPositions(PSBase): """ class of a a lensed point source parameterized as the (multiple) observed image positions Name within the PointSource module: 'LENSED_POSITION' parameters: ra_image, dec_image, point_amp If fixed_magnification=True, than 'source_amp' is a parameter instead of 'point_amp' """ # def __init__(self, lens_model=None, fixed_magnification=False, additional_image=False): # super(LensedPositions, self).__init__(lens_model=lens_model, fixed_magnification=fixed_magnification, # additional_image=additional_image)
[docs] def image_position(self, kwargs_ps, kwargs_lens=None, magnification_limit=None, kwargs_lens_eqn_solver=None): """ on-sky image positions :param kwargs_ps: keyword arguments of the point source model :param kwargs_lens: keyword argument list of the lens model(s), only used when requiring the lens equation solver :param magnification_limit: float >0 or None, if float is set and additional images are computed, only those images will be computed that exceed the lensing magnification (absolute value) limit :param kwargs_lens_eqn_solver: keyword arguments specifying the numerical settings for the lens equation solver see LensEquationSolver() class for details :return: image positions in x, y as arrays """ if self._additional_image is True: if kwargs_lens_eqn_solver is None: kwargs_lens_eqn_solver = {} ra_source, dec_source = self.source_position(kwargs_ps, kwargs_lens) ra_image, dec_image = self._solver.image_position_from_source(ra_source, dec_source, kwargs_lens, magnification_limit=magnification_limit, **kwargs_lens_eqn_solver) else: ra_image = kwargs_ps['ra_image'] dec_image = kwargs_ps['dec_image'] return np.array(ra_image), np.array(dec_image)
[docs] def source_position(self, kwargs_ps, kwargs_lens=None): """ original source position (prior to lensing) :param kwargs_ps: point source keyword arguments :param kwargs_lens: lens model keyword argument list (required to ray-trace back in the source plane) :return: x, y position (as numpy arrays) """ ra_image = kwargs_ps['ra_image'] dec_image = kwargs_ps['dec_image'] x_source, y_source = self._lens_model.ray_shooting(ra_image, dec_image, kwargs_lens) x_source = np.mean(x_source) y_source = np.mean(y_source) return np.array(x_source), np.array(y_source)
[docs] def image_amplitude(self, kwargs_ps, kwargs_lens=None, x_pos=None, y_pos=None, magnification_limit=None, kwargs_lens_eqn_solver=None): """ image brightness amplitudes :param kwargs_ps: keyword arguments of the point source model :param kwargs_lens: keyword argument list of the lens model(s), only used when requiring the lens equation solver :param x_pos: pre-computed image position (no lens equation solver applied) :param y_pos: pre-computed image position (no lens equation solver applied) :param magnification_limit: float >0 or None, if float is set and additional images are computed, only those images will be computed that exceed the lensing magnification (absolute value) limit :param kwargs_lens_eqn_solver: keyword arguments specifying the numerical settings for the lens equation solver see LensEquationSolver() class for details :return: array of image amplitudes """ if self._fixed_magnification: if x_pos is not None and y_pos is not None: ra_image, dec_image = x_pos, y_pos else: ra_image, dec_image = self.image_position(kwargs_ps, kwargs_lens, magnification_limit=magnification_limit, kwargs_lens_eqn_solver=kwargs_lens_eqn_solver) mag = self._lens_model.magnification(ra_image, dec_image, kwargs_lens) point_amp = kwargs_ps['source_amp'] * np.abs(mag) else: point_amp = kwargs_ps['point_amp'] if x_pos is not None: point_amp = _expand_to_array(point_amp, len(x_pos)) return np.array(point_amp)
[docs] def source_amplitude(self, kwargs_ps, kwargs_lens=None): """ intrinsic brightness amplitude of point source When brightnesses are defined in magnified on-sky positions, the intrinsic brightness is computed as the mean in the magnification corrected image position brightnesses. :param kwargs_ps: keyword arguments of the point source model :param kwargs_lens: keyword argument list of the lens model(s), used when brightness are defined in magnified on-sky positions :return: brightness amplitude (as numpy array) """ if self._fixed_magnification: source_amp = kwargs_ps['source_amp'] else: ra_image, dec_image = kwargs_ps['ra_image'], kwargs_ps['dec_image'] mag = self._lens_model.magnification(ra_image, dec_image, kwargs_lens) point_amp = kwargs_ps['point_amp'] source_amp = np.mean(np.array(point_amp) / np.array(np.abs(mag))) return np.array(source_amp)