coshalo {celestial} | R Documentation |

All 6 Virial parameter conversion functions. Each can map precisely to the other as a one paramter function.

coshaloMvirToSigma(Mvir=1e+12, z=0, H0=100, OmegaM=0.3, OmegaL=1-OmegaM-OmegaR, OmegaR=0, Rho='crit', Dist='Co', DeltaVir=200, Munit=1, Lunit=1e6, Vunit=1e3, Dim=3, ref) coshaloSigmaToMvir(Sigma=230, z=0, H0=100, OmegaM=0.3, OmegaL=1-OmegaM-OmegaR, OmegaR=0, Rho='crit', Dist='Co', DeltaVir=200, Munit=1, Lunit=1e6, Vunit=1e3, Dim=3, ref) coshaloMvirToRvir(Mvir=1e12, z=0, H0=100, OmegaM=0.3, OmegaL=1-OmegaM-OmegaR, OmegaR=0, Rho='crit', Dist='Co', DeltaVir=200, Munit=1, Lunit=1e6, Vunit=1e3, Dim=3, ref) coshaloRvirToMvir(Rvir=162.635, z=0, H0=100, OmegaM=0.3, OmegaL=1-OmegaM-OmegaR, OmegaR=0, Rho='crit', Dist='Co', DeltaVir=200, Munit=1, Lunit=1e6, Vunit=1e3, Dim=3, ref) coshaloSigmaToRvir(Sigma=230, z=0, H0=100, OmegaM=0.3, OmegaL=1-OmegaM-OmegaR, OmegaR=0, Rho='crit', Dist='Co', DeltaVir=200, Munit=1, Lunit=1e6, Vunit=1e3, Dim=3, ref) coshaloRvirToSigma(Rvir=162.635, z=0, H0=100, OmegaM=0.3, OmegaL=1-OmegaM-OmegaR, OmegaR=0, Rho='crit', Dist='Co', DeltaVir=200, Munit=1, Lunit=1e6, Vunit=1e3, Dim=3, ref) coshaloSigmaToTvir(Sigma=230, Vunit=1e3, Tunit='K', Type='halo', Dim=3)

`Mvir` |
Mass within virial radius in units of 'Munit'. |

`Sigma` |
Velocity dispersion (3D) within virial radius in units of 'Vunit'. For coshaloSigmaToTvir the Sigma input should be the virial Sigma which can be found by setting DeltaVir='get' in the the other coshalo functions. |

`Rvir` |
Virial radius (3D) in units of 'Lunit'. |

`z` |
Cosmological redshift, where z must be > -1 (can be a vector). |

`H0` |
Hubble constant as defined at z=0 (default is H0=100 (km/s)/Mpc). |

`OmegaM` |
Omega Matter (default is 0.3). |

`OmegaL` |
Omega Lambda (default is for a flat Universe with OmegaL = 1-OmegaM = 0.7). |

`OmegaR` |
Omega Radiation (default is 0, but OmegaM/3400 is typical). |

`Rho` |
Set whether the critical energy density is used (crit) or the mean mass density (mean). |

`Dist` |
Determines the distance type, i.e. whether the Rho critical energy or mean mass densities are calculated with respect to angular / physical distances (Ang) or with respect to comoving distances (Co). In effect this means Rvir values are either angular / physical (Ang) or comoving (Co). It does not affect Mvir <-> Sigma conversions, but does affect Mvir <-> Rvir and Rvir <-> Sigma. |

`DeltaVir` |
Desired overdensity of the halo with respect to Rho. If set to 'get' it will estimate the required DeltaVir for a virial collapse using the |

`Munit` |
Base mass unit in multiples of Msun. |

`Lunit` |
Base length unit in multiples of parsecs. |

`Vunit` |
Base velocity unit in multiples of m/s. |

`Type` |
Specify the 'halo' or 'gas' temperature to be computed. |

`Tunit` |
Specify the output temperature to be Kelvin ('K'), 'eV' or 'keV'. |

`Dim` |
The dimensional type for the halo (either the 2 or 3). 3 (default) means quantities are intrinsic 3D values. 2 means quantities are for projected systems (i.e. radius and velocity dispersion are compressed). From comparisons to simulations (so NFW, c~5 halos) Rvir[proj]=Rvir[3D]/1.37 and Sigma[proj]=Sigma[3D]/sqrt(3). The former has dependence on the halo profile (so is approximate), whereas the latter is a dimensionality argument that should hold for any virialised system. Note that for projected systems Sigma is measured along one dimension: the line-of-site. |

`ref` |
The name of a reference cosmology to use, one of 137 / 737 / Planck / Planck13 / Planck15 / Planck18 / WMAP / WMAP9 / WMAP7 / WMAP5 / WMAP3 / WMAP1 / Millennium / GiggleZ. Planck = Planck18 and WMAP = WMAP9. The usage is case insensitive, so wmap9 is an allowed input. See |

These functions allow for various analytic conversions between the 3 major properties related to virial radius: the mass, velocity dispresion and size. The default properties calculate properties for 1e12 Msun halos and assume masses in Msun, velocities in km/s and distances in Kpc.

`coshaloMvirToSigma` |
Outputs approximate velocity dispersion (in units of Vunit) given mass (this is exactly the escape velocity at Rvir). |

`coshaloSigmaToMvir` |
Outputs mass (in units of Munit) given velocity dispersion. |

`coshaloMvirToRvir` |
Outputs radius (in units of Lunit) given mass. |

`coshaloRvirToMvir` |
Outputs mass (in units of Munit) given radius. |

`coshaloSigmaToRvir` |
Outputs radius (in units of Lunit) given velocity dispersion. |

`coshaloRvirToSigma` |
Outputs approximate velocity dispersion (in units of Vunit) given radius (this is exactly the escape velocity at Rvir). |

`coshaloSigmaToTvir` |
Output temperture (in units of Tunit) given velocity dispersion. Based on Eqns. 3/7/8/9 of Bryan & Norman (1998). |

Aaron Robotham, Chris Power

coshaloSigmaToTvir based on the equations in:

Bryan & Norman, 1998, ApJ, 495, 80

`cosvol`

, `cosmap`

, `cosdist`

, `cosgrow`

, `cosNFW`

coshaloMvirToSigma(1e13) # Velocity in km/s coshaloMvirToSigma(1e13, Vunit=1) # Velocity in m/s coshaloSigmaToMvir(coshaloMvirToSigma(1e13, Vunit=1),Vunit=1) coshaloMvirToRvir(1e13) #Radius in kpc coshaloSigmaToRvir(coshaloMvirToSigma(1e13, Vunit=1),Vunit=1) #Some sanity checks rho_crit200=cosgrowRhoCrit(z=0)*200 #200 times rho critical at z=0 rho_mean200=cosgrowRhoMean(z=0)*200 #200 times rho mean at z=0 #For a 10^12 Msun/h halo, the radius in Mpc/h where the contained density equals rho_crit*200 rad_crit200=(1e12/rho_crit200*3/4/pi)^(1/3) coshaloMvirToRvir(1e12,Lunit=1e6)-rad_crit200 # ~0 as expected #For a 10^12 Msun/h halo, the radius in Mpc/h where the contained density equals rho_crit*200 rad_mean200=(1e12/rho_mean200*3/4/pi)^(1/3) # ~0 as expected coshaloMvirToRvir(1e12,Lunit=1e6,Rho='mean')-rad_mean200

[Package *celestial* version 1.4.6 Index]