Hot Halo Mass Distributions

Class providing the radial mass distribution of hot (virialized) gas in the halo, returned as a massDistributionClass object. The density profile of the hot atmosphere sets the local cooling rate and pressure support, and determines the ram pressure experienced by satellite galaxies. Common profiles include the \(\beta\)-model and hydrostatic equilibrium solutions. The distribution can be weighted by mass or by other quantities for use in different physical calculations.

Default implementation: hotHaloMassDistributionBetaProfile

Methods

get → class(massDistributionClass)

Return the mass distribution of the hot halo.

• type (treeNode ), intent(inout) :: node

• type (enumerationWeightByType), intent(in ), optional :: weightBy

• integer , intent(in ), optional :: weightIndex

hotHaloMassDistributionBetaProfile

A hot halo mass distribution class which adopts a spherically symmetric \(\beta\)-profile density profile for the hot halo. Specifically,

\[\rho_\mathrm{hot halo}(r) \propto \left[ r^2 + r_\mathrm{core}^2 \right]^{3\beta/2},\]

where the core radius, \(r_\mathrm{core}\), is set using the selected cored profile core radius method (see hotHaloMassDistributionCoreRadius). The value of \(\beta\) is specified by the [beta] parameter. The profile is normalized such that the current mass in the hot gas profile is contained within the outer radius of the hot halo, \(r_\mathrm{hot, outer}\).

(Default implementation)

Methods

• initialize — (Re)initialize the parameters of the \(\beta\)-profile mass distribution.

Parameters

• [beta] (real; default 2.0d0/3.0d0) — The value \(\beta\) in a \(\beta\)-model mass distribution.

hotHaloMassDistributionEnzoHydrostatic

A hot halo mass distribution class which adopts a spherically symmetric density profile for the hot halo motivated by the “hydrostatic” profile available in the ENZO code. Specifically,

\[\begin{split}\rho_\mathrm{hot halo}(r) \propto \left\{ \begin{array}{ll} T^{-1} r^{-1} & \hbox{ if } r > r_\mathrm{core} \\ T^{-1} r_\mathrm{core}^{-1} & \hbox{ if } r \le r_\mathrm{core}, \end{array} \right.\end{split}\]

where the core radius, \(r_\mathrm{core}\), is set using the selected cored profile core radius method (see hotHaloMassDistributionCoreRadius). The profile is normalized such that the current mass in the hot gas profile is contained within the outer radius of the hot halo, \(r_\mathrm{hot, outer}\). Note that the ENZO hydrostatic profile does not include this core, but without introducing this the profile mass can be divergent at small radii.

Methods

• normalizationDensity — Return the normalization of the density profile.

hotHaloMassDistributionNull

A hot halo mass distribution class that assumes no hot halo mass distribution. It is useful, for example, when performing dark matter-only calculations.

hotHaloMassDistributionPatejLoeb2015

Provides an implementation of the hot halo mass distribution class using the circumgalactic medium model of Patej and Loeb (2015), in which the gas density follows a power-law profile tied to the dark matter distribution. The density slope is controlled by [gamma], and the shock radius by [radiusShock].

Methods

• radiusDarkMatter — Return the corresponding radius in the dark matter profile.

• coordinatesDarkMatter — Return the corresponding coordinates in the dark matter profile.

Parameters

• [gamma] (real; default 1.15d0) — The parameter \(\Gamma\) in the Patej and Loeb (2015) mass distribution.

• [radiusShock] (real; default 1.0d0) — The shock radius, \(s\), (in units of the halo virial radius) in the Patej and Loeb (2015) hot halo gas mass distribution model.

hotHaloMassDistributionRicotti2000

A hot halo mass distribution class which adopts a spherically symmetric \(\beta\)-profile density profile for the hot halo with parameters selected using the fitting function of Ricotti and Shull (2000) who found these by solving for hydrostatic equilibrium in an NFW density profile. Specifically, \(\beta = 0.9 b\) where

\[b = {2 c \over 9 \Gamma} \left[ \log(1+c) - {c\over 1+c}\right]^{-1},\]

\(c\) is the concentration parameter of the dark matter halo, and \(\Gamma\) is the ratio of virial and gas temperatures, which is assumed to be unity. The core radius is \(r_\mathrm{core} = 0.22 r_\mathrm{s}\) where \(r_\mathrm{s}\) is the scale radius of the dark matter profile. The profile is normalized such that the current mass in the hot gas profile is contained within the outer radius of the hot halo, \(r_\mathrm{hot, outer}\).

Parameters

• [beta] (real; default 2.0d0/3.0d0) — The value of \(\beta\) in \(\beta\)-profile hot halo mass distributions. (inherited from hotHaloMassDistributionBetaProfile)