Intergalactic Medium Filtering Mass

Class providing models of the IGM filtering mass—the characteristic halo mass scale below which photo-ionization heating of the IGM suppresses gas accretion. Photo-ionization by the UV background raises the IGM temperature to \(\sim 10^4\) K, increasing the Jeans mass and preventing low-mass halos from accreting their full cosmic baryon fraction. Implementations return the filtering mass \(M_\mathrm{F}(t)\) (and its rate of change), and the suppressed baryon fraction \(f_\mathrm{b}(M,t)\) relative to the cosmic mean, governing star formation in dwarf galaxies.

Default implementation: intergalacticMediumFilteringMassGnedin2000

Methods

massFiltering → double precision

Return the filtering mass at the given time.

  • double precision, intent(in ) :: time

massFilteringRateOfChange → double precision

Return the rate of change of the filtering mass at the given time.

  • double precision, intent(in ) :: time

fractionBaryons → double precision

Return the fraction of baryons accreted into a halo of the given mass at the time.

  • double precision, intent(in ) :: mass, time

fractionBaryonsGradientMass → double precision

Return the gradient with respect to mass of the fraction of baryons accreted into a halo of the given mass at the time.

  • double precision, intent(in ) :: mass, time

fractionBaryonsRateOfChange → double precision

Return the rate of change of the fraction of baryons accreted into a halo of the given mass at the time.

  • double precision, intent(in ) :: mass, time

intergalacticMediumFilteringMassGnedin2000

An implementation of the Gnedin (2000) filtering mass calculation, which determines the characteristic halo mass below which gas accretion is suppressed by photoionization heating from the intergalactic radiation field. The filtering mass is computed by integrating an ODE system driven by the IGM thermal state and linear growth history.

(Default implementation)

Methods

  • tabulate — Tabulate the filtering mass to encompass at least the given time.

  • conditionsInitialODEs — Set the initial conditions for the ODE system.

  • coefficientsEarlyEpoch — Return coefficients for the early-epoch fitting function to the filtering mass.

  • massFilteringEarlyEpoch — Return the early-epoch solution for the filtering mass.

  • fileWrite — Store the tabulate filtering mass to file.

  • fileRead — Restore the tabulate filtering mass from file.

  • remakeTable — Return true if the table must be remade.

Parameters

  • [timeTooEarlyIsFatal] (default .true.) — If true, requesting the filtering mass at a time earlier than the initial time provided by the Naoz and Barkana (2005) fit will result in a fatal error. Otherwise, the filtering mass is fixed at this initial value for earlier times.