Physics ParametersΒΆ
radiative_transfer
- No astrophysical sources.
- Includes ionization/heating from astrophysical sources.
Default: 1
compton_scattering
- OFF
- Include Compton scattering between free electrons and CMB.
Default: 1
secondary_ionization
Determine what fraction of photo-electron energy gets deposited in various channels, such as heat, ionization, and excitation.
- All photo-electron energy deposited as heat.
- Compute using fits of Shull & vanSteenberg (1985).
- Compute using energy-dependent fits of Ricotti, Gnedin, & Shull (2002).
- Compute using look-up tables of Furlanetto & Stoever (2010).
Default: 1
fXh
Set fractional heating by photo-electrons by-hand. Currently must be a constant. Will override choice of
secondary_ionization
if supplied.Default:
None
clumping_factor
Multiplicative enhancement to the recombination rate.
Default: 1
approx_He
- See following table for possible behaviors depending on value of
include_He
. Default: False
include_He |
approx_He |
description |
---|---|---|
False | False | Neglects helium entirely |
True | True | Set \(x_{\text{HeII}} = x_{\text{HII}}\), and set \(x_{\text{HeIII}} = 0\) |
True | False | Solve for helium self-consistently |
approx_sigma
- Compute bound-free absorption cross sections via fits of Verner et al. (1996).
- Approximate cross-sections as \(\sigma \propto \nu^{-3}\)
Default: 0
approx_lwb
- Solves RTE (i.e., full “sawtooth” background).
- Assume flat spectrum between Lyman-\(\alpha\) and the Lyman limit.
Default: 1
approx_xrb
- Solves RTE.
- Heating due to instantaneous X-ray luminosity.
Default: 1
discrete_lwb
- Performs integrals numerically using continuous functions for integrands (very slow)
- Integrates transfer equation over discrete set of points.
Default: 1
discrete_xrb
- Performs integrals numerically using continuous functions for integrands (very slow)
- Integrates transfer equation over discrete set of points.
Default: 1
approx_Salpha
- Not implemented
- Assume \(S_{\alpha} = 1\)
- Use formulae of Chuzhoy, Alvarez, & Shapiro (2005).
- Use formulae of Furlanetto & Pritchard (2006)
Default: 1
lya_nmax
- Default: 23
lya_injected
Include photons injected at line-center?
Default:
True
lya_continuum
Include photons redshifting into the blue-wing of the Lyman-\(\alpha\) line?
Default:
True
recombination
Which recombination method to use? Can be
"A"
,"B"
, or0
, the first two options being standard case-A or case-B recombination, whereas the last option artificially turns off recombinations (useful for analytic tests).Default:
B