TPCI: The PLUTO-CLOUDY Interface

TL;DR

The paper introduces TPCI, a novel interface combining PLUTO and CLOUDY to simulate photoevaporative flows under strong irradiation, enabling advanced astrophysical modeling of photoionization and hydrodynamics.

Contribution

The paper presents a new interface, TPCI, integrating CLOUDY with PLUTO for coupled photoionization and hydrodynamics simulations, validated through multiple astrophysical test problems.

Findings

Successfully simulated photoevaporation of hydrogen clouds

Modeled cooling of coronal plasma accurately

Reproduced Stroemgren sphere formation

Abstract

We present an interface between the (magneto-) hydrodynamics code PLUTO and the plasma simulation and spectral synthesis code CLOUDY. By combining these codes, we constructed a new photoionization hydrodynamics solver: The PLUTO-CLOUDY Interface (TPCI), which is well suited to simulate photoevaporative flows under strong irradiation. The code includes the electromagnetic spectrum from X-rays to the radio range and solves the photoionization and chemical network of the 30 lightest elements. TPCI follows an iterative numerical scheme: First, the equilibrium state of the medium is solved for a given radiation field by CLOUDY, resulting in a net radiative heating or cooling. In the second step, the latter influences the (magneto-) hydrodynamic evolution calculated by PLUTO. Here, we validated the one-dimensional version of the code on the basis of four test problems: Photoevaporation of a cool hydrogen cloud, cooling of coronal plasma, formation of a Stroemgren sphere, and the evaporating atmosphere of a hot Jupiter. This combination of an equilibrium photoionization solver with a general MHD code provides an advanced simulation tool applicable to a variety of astrophysical problems.