Multi-physics framework for fast modeling of gamma-ray burst afterglows

TL;DR

PyBlastAfterglow is an open-source, modular, and fast C++/Python tool for modeling gamma-ray burst afterglows, capable of simulating complex emission scenarios including reverse shocks, high-energy emission, and off-axis observations.

Contribution

The paper introduces PyBlastAfterglow, a versatile and extendable code that integrates multiple physical models for detailed gamma-ray burst afterglow simulations.

Findings

Efficient modeling of complex afterglow light curves and sky maps.

Inclusion of reverse shock, high-energy emission, and structured jets.

Open-source tool facilitating parameter studies and physics testing.

Abstract

In this paper, we present PyBlastAfterglow, a modular C++ code with a Python interface to model light curves and sky maps of gamma-ray burst afterglows. The code is open-source, modular, and sufficiently fast to perform parameter grid studies. PyBlastAfterglow is designed to be easily extendable and used as a testing bed for new physics and methods related to gamma-ray burst afterglows. For the dynamical evolution of relativistic ejecta, a thin-shell approximation is adopted, where both forward and reverse shocks are included self-consistently, as well as lateral structure, lateral spreading, and radiation losses. Several models of the shock microphysics are implemented, including a fully numerical model of the downstream electron distribution evolution, synchrotron emission, self-absorption, and synchrotron self-Compton emission under the one-zone approximation. Thus, the code is designed to be able to model complex afterglows that include emission from reverse shock, very high energy emission, structured jets, and off-axis observations.