def __init__(self, z_lens, z_source, cosmo=None):
"""
:param z_lens: redshift of lens
:param z_source: redshift of source
:param cosmo: astropy.cosmology instance
"""
self.z_lens = z_lens
self.z_source = z_source
self.background = Background(cosmo=cosmo)
self.nfw_param = NFWParam()
def test_against_colossus(self):
"""
This test class asks to get the same parameters back as colossus: https://bdiemer.bitbucket.io/colossus/index.html
"""
cosmo = FlatLambdaCDM(H0=70, Om0=0.285, Ob0=0.05)
nfw_param = NFWParam(cosmo=cosmo)
from colossus.cosmology import cosmology as cosmology_colossus
from colossus.halo.profile_nfw import NFWProfile
colossus_kwargs = {
'H0': 70,
'Om0': 0.285,
'Ob0': 0.05,
'ns': 0.96,
'sigma8': 0.82,
'persistence': ''
}
colossus = cosmology_colossus.setCosmology('custom', colossus_kwargs)
m200 = 10**8
c = 17.
zvals = np.linspace(0.0, 2, 50)
h = 0.7
for z in zvals:
nfw_colossus = NFWProfile(M=m200 * h, z=z, c=c, mdef='200c')
rhos_colossus, rs_colossus = nfw_colossus.nativeParameters(
m200 * h, c, z, mdef='200c')
r200_colossus = rs_colossus * c
# according to colossus documentation the density is in physical units[M h^2/kpc^3] and distance [kpc/h]
rs_colossus *= h**-1
rhos_colossus *= h**2
r200_lenstronomy = nfw_param.r200_M(m200 * h,
z) / h # physical radius r200
rs_lenstronomy = r200_lenstronomy / c
rhos_lenstronomy = nfw_param.rho0_c(
c, z) * h**2 # physical density in M_sun/Mpc**3
# convert Mpc to kpc
rhos_lenstronomy *= 1000**-3
rs_lenstronomy *= 1000
npt.assert_almost_equal(rs_lenstronomy / rs_colossus, 1, decimal=3)
npt.assert_almost_equal(rhos_lenstronomy / rhos_colossus,
1,
decimal=3)
def setup(self):
z_L = 0.8
z_S = 3.0
from astropy.cosmology import FlatLambdaCDM
cosmo = FlatLambdaCDM(H0=70, Om0=0.3, Ob0=0.05)
self.nfwParam = NFWParam()
def setup(self):
cosmo = FlatLambdaCDM(H0=70, Om0=0.3, Ob0=0.05)
self.nfwParam = NFWParam(cosmo=cosmo)
self.z = 0.5 # needed fixed redshift for the inversion function