galapy.InterGalacticMedium

Approximated IGM attenuation.

Classes

IGM()

Class for handling intergalactic medium (IGM) properties.
class galapy.InterGalacticMedium.IGM

Class for handling intergalactic medium (IGM) properties.

Implements the approximated model from Eqs. (20-21-25-26-27-28-29) in Inoue et al., 2014 given in terms of the piece-wise equation

\[\tau_\text{IGM}(\lambda_\text{O}, z) = \tau_\text{LC}^\text{LAF}(\lambda_\text{O}, z) + \tau_\text{LS}^\text{LAF}(\lambda_\text{O}, z) + \tau_\text{LC}^\text{DLA}(\lambda_\text{O}, z) + \tau_\text{LS}^\text{DLA}(\lambda_\text{O}, z)\]

provided in terms of the equations for the Lyman-series (LS) and Lyman-continuum (LC) absorption from Damped Lyman-\(\alpha\) systems (DLA) and from the Lyman-\(\alpha\) Forest (LAF).

LymanLimit = 912.0

Wavelength corresponding to the Lyman limit in Angstroms.

Type:

float

LS_LAF(lobs, zobs)

Compute the optical depth due to Lyman series absorption for the Lyman-alpha forest contribute.

Parameters:

  • lobs (numpy.ndarray) – Observed wavelengths.

  • zobs (float) – Redshift of the source.

Returns:

Lyman series optical depth due to Lyman-alpha forest.

Return type:

numpy.ndarray

LS_DLA(lobs, zobs)

Compute the optical depth due to Lyman series absorption for the Damped Lyman-alpha systems contribute.

Parameters:

  • lobs (numpy.ndarray) – Observed wavelengths.

  • zobs (float) – Redshift of the source.

Returns:

Lyman series optical depth due to Damped Lyman-alpha systems.

Return type:

numpy.ndarray

LC_LAF(lobs, zobs)

Compute the optical depth due to Lyman continuum absorption for the Lyman-alpha forest contribute.

Parameters:

  • lobs (numpy.ndarray) – Observed wavelengths.

  • zobs (float) – Redshift of the source.

Returns:

Lyman continuum optical depth due to Lyman-alpha forest.

Return type:

numpy.ndarray

LC_DLA(lobs, zobs)

Compute the optical depth due to Lyman continuum absorption for the Damped Lyman-alpha systems contribute.

Parameters:

  • lobs (numpy.ndarray) – Observed wavelengths.

  • zobs (float) – Redshift of the source.

Returns:

Lyman continuum optical depth due to Damped Lyman-alpha systems.

Return type:

numpy.ndarray

optical_depth(lobs, zobs)

Overall contribution to the optical depth, damping ultra-violet photons due to the absorption from the intergalactic medium (IGM) using the piece-wise fitting functions from Inoue et al., 2014.

Parameters:

  • lobs (numpy.ndarray) – Observed wavelengths.

  • zobs (float) – Redshift of the source.

Returns:

IGM optical depth.

Return type:

numpy.ndarray

transmission(lobs, zobs)

Overall transmission of IGM.

computed as \(e^{-\tau_\text{IGM}(\lambda_\text{O}, z)}\) where \(\tau_\text{IGM}\) is computed with equation galapy.InterGalacticMedium.IGM.optical_depth()

Parameters:

  • lobs (numpy.ndarray) – Observed wavelengths.

  • zobs (float) – Redshift of the source.

Returns:

IGM transmission.

Return type:

numpy.ndarray