Source code for lenstronomy.LightModel.Profiles.nie

import numpy as np
import lenstronomy.Util.param_util as param_util
from lenstronomy.Util import util
from lenstronomy.LightModel.Profiles.profile_base import LightProfileBase

__all__ = ['NIE']


[docs]class NIE(LightProfileBase): """ non-divergent isothermal ellipse (projected) This is effectively the convergence profile of the NIE lens model with an amplitude 'amp' rather than an Einstein radius 'theta_E' """ param_names = ['amp', 'e1', 'e2', 's_scale', 'center_x', 'center_y'] lower_limit_default = {'amp': 0, 'e1': -0.5, 'e2': -0.5, 's_scale': 0, 'center_x': -100, 'center_y': -100} upper_limit_default = {'amp': 100, 'e1': 0.5, 'e2': 0.5, 's_scale': 100, 'center_x': 100, 'center_y': 100}
[docs] def function(self, x, y, amp, e1, e2, s_scale, center_x=0, center_y=0): """ :param x: x-coordinate :param y: y-coordinate :param amp: surface brightness normalization :param e1: eccentricity component :param e2: eccentricity component :param s_scale: smoothing scale (square averaged of minor and major axis) :param center_x: center of profile :param center_y: center of profile :return: surface brightness of NIE profile """ x_ = x - center_x y_ = y - center_y phi_G, q = param_util.ellipticity2phi_q(e1, e2) # rotate x__, y__ = util.rotate(x_, y_, phi_G) s = s_scale * np.sqrt((1 + q ** 2) / (2 * q ** 2)) f_ = amp/2. * (q**2 * (s**2 + x__**2) + y__**2)**(-1./2) return f_