PLUTO-SIROCCO

Monte Carlo Radiation Hydrodynamics (MC-RHD) of Line-Driven Disc Winds

This repository contains a version of the PLUTO v4.4.3 astrophysical fluid dynamics code that has been custom-modified to interface with the SIROCCO radiative transfer code and a separate CAK force multiplier solver**. Together, this software should allow the user to perform radiation–hydrodynamics (RHD) simulations of line-driven disc winds (or in principle, radiative or thermal type of disc wind).

We implement a modular, operator-split approach to simulate disc winds:

• PLUTO handles the hydrodynamic evolution of the gas (density, velocity, pressure, temperature).
• SIROCCO performs frequency-dependent Monte Carlo radiative transfer, calculating the local radiation field and ionization states of the gas.
• CAK (Castor-Abbott-Klein) solver calculates the force multiplier — a function that quantifies how much the radiation pressure is boosted due to line absorption.

These three modules are called in sequence at each radiation timestep, forming a coupled loop. For further detail, please consult the following papers:

Monte-Carlo radiation hydrodynamic simulations of line-driven disc winds: relaxing the isothermal approximation, Mosallanezhad et al., MNRAS in press

State-of-the-art simulations of line-driven accretion disc winds: realistic radiation hydrodynamics leads to weaker outflows, Higginbottom, Scepi et al., MNRAS, Volume 527, Issue 3, pp.9236-9249, arXiv:2312.06042

Please cite these papers if you use the software, together with the SIROCCO release paper and PLUTO code paper (Mignone et al. 2007).

⚙️ Code Structure Summary

• cak_v3/ — atomic_models.txt, transitiondata.txt, cak_v3 executable
• pluto_sirocco_*.py — Python drivers and control scripts
• init.c, line_connect.c, cooling.c, etc. — Custom PLUTO source code

Setups for running models from Mosallanezhad et al. (including further parameter descriptions) can be found in Test_Problems/LineDrivenWind

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🔧 Installation Guide

1. Install SIROCCO

git clone https://github.com/sirocco-rt/sirocco.git
cd sirocco/source
# Replace the rad_hydro_files.c with the custom version

Update your environment:

export SIROCCO=/path/to/sirocco
export PATH=$SIROCCO/bin:$PATH
source ~/.bashrc  # or ~/.zshrc

Build SIROCCO:

cd $SIROCCO
./configure
make install 2>&1 | tee install_log.txt
make clean

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2. Install PLUTO-SIROCCO v1.0

git clone https://github.com/sirocco-rt/pluto-sirocco.git

If you downloaded the .zip file manually, unzip it and rename the extracted folder to PLUTO for consistency with environment variables used in the rest of this guide.

Update your environment:

export PLUTO_DIR=/path/to/PLUTO
source ~/.bashrc  # or ~/.zshrc

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3. Install pyPLUTO (custom version)

cd $PLUTO_DIR/Tools/pyPLUTO
python3 setup.py install  # Or with sudo if needed

⚠️ Do not use pyPLUTO from other versions. This one includes required changes to pload.py.
More info

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4. Install CAK

cd $PLUTO_DIR/Test_Problems/LineDrivenWind/cak_v3
make

Copy the cak_v3 executable (only) to your working directory. Do not run the makefile outside the cak_v3 folder.

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🧪 Running the Code

cd $PLUTO_DIR/Test_Problems/LineDrivenWind
cp -r cv_idl ~/my_sim_dir
cd ~/my_sim_dir
python3 $PLUTO_DIR/setup.py

Configuration highlights:

• EOS: IDEAL or ISOTHERMAL
• COOLING: BLONDIN (for IDEAL)
• BODY_FORCE: VECTOR
• LINE_DRIVEN_WIND: SIROCCO_MODE

Then:

make
make clean

Review config file:

nano pluto_sirocco_config.py

Run simulation:

python3 ./pluto_sirocco_dir_iso.py

Monitor output:

tail -f sirocco_log

If config is changed:

python3 ./pluto_sirocco_init.py

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👩‍💻 Contributors

• Amin Mosallanezhad
• Nicolas Scepi
• Nick Higginbottom
• SIROCCO collaboration
• PLUTO developers

📄 License

This repository is distributed under the GPL-2.0 license, in line with PLUTO and SIROCCO.

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📬 Contact

For questions, please contact:
Amin Mosallanezhad — a.mosallanezhad@soton.ac.uk