import lenstronomy.Util.param_util as param_util
import numpy as np
__all__ = ["Hernquist", "HernquistEllipse"]
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class Hernquist(object):
"""Class for Hernquist lens light (2d projected light/mass distribution)."""
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def __init__(self):
from lenstronomy.LensModel.Profiles.hernquist import Hernquist as Hernquist_lens
self.lens = Hernquist_lens()
self.param_names = ["amp", "Rs", "center_x", "center_y"]
self.lower_limit_default = {
"amp": 0,
"Rs": 0,
"center_x": -100,
"center_y": -100,
}
self.upper_limit_default = {
"amp": 100,
"Rs": 100,
"center_x": 100,
"center_y": 100,
}
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def function(self, x, y, amp, Rs, center_x=0, center_y=0):
"""
:param x: x-position
:param y: y-position
:param amp: surface brightness amplitude
:param Rs: scale radius: half-light radius = Rs / 0.551
:param center_x: centroid in x-direction
:param center_y: centroid in y-direction
:return: surface brightness
"""
rho0 = self.lens.sigma2rho(amp, Rs)
return self.lens.density_2d(x, y, rho0, Rs, center_x, center_y)
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def light_3d(self, r, amp, Rs):
"""
:param r: 3d radius (in angular units)
:param amp: surface brightness amplitude
:param Rs: scale radius: half-light radius = Rs / 0.551
:return:
"""
rho0 = self.lens.sigma2rho(amp, Rs)
return self.lens.density(r, rho0, Rs)
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@staticmethod
def total_flux(amp, Rs, center_x=0, center_y=0):
"""
:param amp: surface brightness amplitude
:param Rs: scale radius: half-light radius = Rs / 0.551
:return: total integrated flux of profile
"""
rhos = amp / Rs
m_tot = 2 * np.pi * rhos * Rs**3
return m_tot
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class HernquistEllipse(object):
"""Class for elliptical pseudo Jaffe lens light (2d projected light/mass
distribution."""
param_names = ["amp", "Rs", "e1", "e2", "center_x", "center_y"]
lower_limit_default = {
"amp": 0,
"Rs": 0,
"e1": -0.5,
"e2": -0.5,
"center_x": -100,
"center_y": -100,
}
upper_limit_default = {
"amp": 100,
"Rs": 100,
"e1": 0.5,
"e2": 0.5,
"center_x": 100,
"center_y": 100,
}
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def __init__(self):
from lenstronomy.LensModel.Profiles.hernquist import Hernquist as Hernquist_lens
self.lens = Hernquist_lens()
self.spherical = Hernquist()
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def function(self, x, y, amp, Rs, e1, e2, center_x=0, center_y=0):
"""
:param x: x-position
:param y: y-position
:param amp: surface brightness amplitude
:param Rs: scale radius: half-light radius = Rs / 0.551
:param e1: eccentricity component
:param e2: eccentricity component
:param center_x: centroid in x-direction
:param center_y: centroid in y-direction
:return: surface brightness
"""
x_, y_ = param_util.transform_e1e2_product_average(
x, y, e1, e2, center_x, center_y
)
return self.spherical.function(x_, y_, amp, Rs)
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def light_3d(self, r, amp, Rs, e1=0, e2=0, **kwargs):
"""
:param r: 3d radius (in angular units)
:param amp: surface brightness amplitude
:param Rs: scale radius: half-light radius = Rs / 0.551
:param e1: eccentricity component
:param e2: eccentricity component
:return: flux density in 3d
"""
rho0 = self.lens.sigma2rho(amp, Rs)
return self.lens.density(r, rho0, Rs)
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def total_flux(self, amp, Rs, **kwargs):
"""
:param amp: surface brightness amplitude
:param Rs: scale radius: half-light radius = Rs / 0.551
:return: total integrated flux
"""
return self.spherical.total_flux(amp=amp, Rs=Rs)