A simple gaussian line profile. If the width is ≤ 0 then
it is treated as a delta function. The **zagauss** variant computes a
redshifted gaussian.

where:

par1 = λ |
line wavelength in Angstrom |

par2 = s |
line width in Angstrom |

Norm = |
total photons cm |

For **zagauss** the corresponding formula is:

and parameter settings are:

par1 = λ |
line wavelength in Angstrom |

par2 = σ |
line width in Angstrom |

par3 = z |
redshift |

Norm = K |
total photons cm |