cofm module

Calculate halo concentration from mass and redshift.

clusterlensing.cofm.c_Duffy(z, m, h=0.6777)

Concentration from c(M) relation published in Duffy et al. (2008).

Parameters:

z : float or array_like

Redshift(s) of halos.

m : float or array_like

Mass(es) of halos (m200 definition), in units of solar masses.

h : float, optional

Hubble parameter. Default is from Planck13.

Returns:

ndarray :

Concentration values (c200) for halos.

References

Results from N-body simulations using WMAP5 cosmology, presented in:

A.R. Duffy, J. Schaye, S.T. Kay, and C. Dalla Vecchia, “Dark matter halo concentrations in the Wilkinson Microwave Anisotropy Probe year 5 cosmology,” Monthly Notices of the Royal Astronomical Society, Volume 390, Issue 1, pp. L64-L68, 2008.

This calculation uses the parameters corresponding to the NFW model, the ‘200’ halo definition, and the ‘full’ sample of halos spanning z = 0-2. This means the values of fitted parameters (A,B,C) = (5.71, -0.084,-0.47) in Table 1 of Duffy et al. (2008).

clusterlensing.cofm.c_DuttonMaccio(z, m, h=0.6777)

Concentration from c(M) relation in Dutton & Maccio (2014).

Parameters:

z : float or array_like

Redshift(s) of halos.

m : float or array_like

Mass(es) of halos (m200 definition), in units of solar masses.

h : float, optional

Hubble parameter. Default is from Planck13.

Returns:

ndarray :

Concentration values (c200) for halos.

References

Calculation from Planck-based results of simulations presented in:

A.A. Dutton & A.V. Maccio, “Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles,” Monthly Notices of the Royal Astronomical Society, Volume 441, Issue 4, p.3359-3374, 2014.

clusterlensing.cofm.c_Prada(z, m, h=0.6777, Om_M=0.30712, Om_L=0.6928799999999999)

Concentration from c(M) relation published in Prada et al. (2012).

Parameters:

z : float or array_like

Redshift(s) of halos.

m : float or array_like

Mass(es) of halos (m200 definition), in units of solar masses.

h : float, optional

Hubble parameter. Default is from Planck13.

Om_M : float, optional

Matter density parameter. Default is from Planck13.

Om_L : float, optional

Cosmological constant density parameter. Default is from Planck13.

Returns:

ndarray :

Concentration values (c200) for halos.

Notes

This c(M) relation is somewhat controversial, due to its upturn in concentration for high masses (normally we expect concentration to decrease with increasing mass). See the reference below for discussion.

References

Calculation based on results of N-body simulations presented in:

F. Prada, A.A. Klypin, A.J. Cuesta, J.E. Betancort-Rijo, and J. Primack, “Halo concentrations in the standard Lambda cold dark matter cosmology,” Monthly Notices of the Royal Astronomical Society, Volume 423, Issue 4, pp. 3018-3030, 2012.