halox.halo.einasto: The Einasto profile#
halox provides utility functions to compute properties of halos with an Einasto profile.
For examples, see Einasto Profiles.
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Properties of a dark matter halo following an Einasto profile. |
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Einasto alpha parameter from the Gao et al. 2008 peak height relation. |
- class halox.halo.einasto.EinastoHalo(m_delta, c_delta, z, alpha, cosmo, delta=200)[source]#
Properties of a dark matter halo following an Einasto profile. Units in Mpc and solar masses
- Parameters:
m_delta (float) – Mass at overdensity delta [h-1 Msun]
c_delta (float) – Concentration at overdensity delta
z (float) – Redshift
alpha (float) – Einasto profile alpha parameter.
cosmo (jc.Cosmology) – Underlying cosmology
delta (float) – Density contrast in units of critical density at redshift z, defaults to 200.
- density(r)[source]#
Einasto density profile \(\rho(r)\).
- Parameters:
r (Array [h-1 Mpc]) – Radius
- Returns:
Density at radius r
- Return type:
Array [h2 Msun Mpc-3]
- enclosed_mass(r)[source]#
Enclosed mass profile \(M(<r)\).
- Parameters:
r (Array [h-1 Mpc]) – Radius
- Returns:
Enclosed mass at radius r
- Return type:
Array [h-1 Msun]
- circular_velocity(r)[source]#
Circular velocity profile \(v_c(r)\).
The circular velocity is related to the enclosed mass by: \(v_c^2(r) = GM(<r)/r\)
- Parameters:
r (Array [h-1 Mpc]) – Radius
- Returns:
Circular velocity at radius r
- Return type:
Array [km s-1]
- potential(r)[source]#
Potential profile \(\phi(r)\).
- Parameters:
r (Array [h-1 Mpc]) – Radius
- Returns:
Potential at radius r
- Return type:
Array [km2 s-2]
- to_delta(delta_new)[source]#
Convert halo properties to a different overdensity definition.
- Parameters:
delta_new (float) – New density contrast in units of critical density at redshift z
- Return type:
tuple[Array,Array,Array]- Returns:
Array [h-1 Msun] – Mass at new overdensity
Array [h-1 Mpc] – Radius at new overdensity
Array – Concentration at new overdensity
Notes
This conversion assumes an NFW profile.
- halox.halo.einasto.a_from_nu(M, z, cosmo, n_k_int=5000, delta_sc=1.686)[source]#
Einasto alpha parameter from the Gao et al. 2008 peak height relation.
- Parameters:
M (Array) – Virial mass [h-1 Msun]
z (Array) – Redshift
cosmo (jc.Cosmology) – Underlying cosmology
n_k_int (int) – Number of k-space integration points for \(\sigma(R,z)\), default 5000
delta_sc (float) – Spherical collapse overdensity, default 1.686
- Returns:
Einasto alpha parameter
- Return type:
Array
Notes
This assumes that the input mass is the virial mass.