grbcomp: Comptonization for GRB prompt emission

This model has been proposed by Titarchuk et al. (2012) as a possible scenario for the spectral emission of the prompt phase of Gamma Ray Bursts.

It is essentially a two-phase model: up to the peak energy E of the EF(E) spectrum soft thermal blackbody-like photons are comptonized by a subrelativistic bulk outflow of thermal electrons, while the high-energy tail is obtained by a further convolution of the formerly comptonized spectrum with a Green's function. An example of the application of the model to a sample of GRBs can be found in Frontera et al. (2013).

par1 | kTs, temperature of the seed blackbody spectrum (keV) |

par2 | gamma, when it is set = 3 the seed soft spectrum is a blackbody, otherwise it approximates a modified blackbody |

par3 | kTe, electron temperature of the subrelativistic outflow (keV) |

par4 | tau, radial optical depth of the subrelativistic outflow |

par5 | beta, bulk outflow velocity of the thermal electrons |

par6 | fbflag, if set = 0 only the first-order bulk Comptonization term is considered, if set = 1 also the second-order term is computed, where |

par7 | log(A), geometrical covering factor which determines the relative weights of the seed and comptonized spectra to the total flux |

par8 | z, redshift |

par9 | a_boost, energy index of the Green's function with which the formerly comptonization spectrum is convolved |

norm | , where is the apparent blackbody radius in units of cm and is the sorce distance in Mpc |