Dr. Simon Stevenson
SS
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Simon Stevenson

Astrophysicist & Adjunct Research Fellow

Scientific Software Engineer & Data Scientist

I simulate the stellar lifecycles of massive stars to understand how they evolve, die, and merge as compact binaries (neutron stars and black holes), producing the gravitational waves detected by LIGO, Virgo, and KAGRA.

I build high-performance scientific simulations, statistical inference pipelines, and machine learning models to solve complex numerical problems, translating mathematical equations into production-ready software.

Explore Projects

Looking for my industry skills (software engineering, HPC, data pipelines)? Try toggling the Industry Mode button in the navigation bar!

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Updates

Latest News

Jul 2026

Modern Mass-Loss Rates Shape Compact Object Mergers

New study examining how updated stellar wind mass-loss prescriptions affect the formation of merging neutron stars and black holes. Published in The Astrophysical Journal.

Read Paper →
Feb 2026

Observation of GW250114 & Hawking's Area Law

Co-authored a new study on the massive gravitational wave event GW250114, confirming Hawking's Black Hole Area Law. I wrote an article in The Conversation about this milestone:

Read Article →
Late 2025 / 2026

LVK Catalogs GWTC-4.0 & GWTC-5.0 Released

The LIGO-Virgo-KAGRA Collaboration has released the GWTC-4.0 and GWTC-5.0 gravitational-wave transient catalogs. These datasets expand our sample of merging black holes and neutron stars by hundreds of events.

Collaboration Big Data
Biography

About Me

I am an Associate Investigator at the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) and an Adjunct Research Fellow within the Centre for Astrophysics and Supercomputing at Swinburne University of Technology. I am also a member of the LIGO-Virgo-KAGRA (LVK) Collaboration.

My research bridges gravitational-wave observations and theoretical stellar astrophysics. I investigate the formation pathways of merging compact objects—binary black holes, binary neutron stars, and neutron star-black hole systems. By using and co-developing rapid binary population synthesis tools, I model how isolated massive binary systems interact through mass transfer, common-envelope phases, and stellar winds.

Previously, I was awarded an Australian Research Council Discovery Early Career Researcher Award (DECRA) Fellowship to study gravitational-wave progenitors. I completed my PhD in Astrophysics at the University of Birmingham in 2017.

I am a Scientific Software Architect with 9+ years of experience engineering complex numerical simulations, statistical data pipelines, and database querying engines for astrophysical data. I am a member of the international LIGO-Virgo-KAGRA Collaboration.

I specialize in building and optimizing rapid binary stellar population models (such as `COMPAS`), running massive parallelized simulations on high-performance computing (HPC) clusters, and using Bayesian inference techniques to align model predictions with observational constraints. My daily work involves designing object-oriented simulation code (in C++ and Python), maintaining open-source codebases, and translating statistical formulas into clean, high-performance algorithms.

I hold a PhD in Astrophysics and specialize in quantitative modeling, statistical distributions, data visualization, and open-source software collaboration.

Portfolio

Selected Projects & Software

Scientific software, population synthesis pipelines, and stellar evolution models.

Open-source software, parallel computing systems, and data pipelines.

COMPAS Code

Compact Object Mergers: Population Astrophysics and Statistics. A rapid binary population synthesis code designed to simulate millions of isolated stellar systems on cluster computing architectures.

Co-creator of a large-scale, high-performance Monte Carlo simulation suite written in C++ and Python. Models massive multi-variate statistical distributions using multi-threaded execution and containerization.

C++ Python HPC
Code →

METISSE

Stellar evolution interpolation framework written in Fortran. METISSE enables rapid population synthesis codes to interpolate stellar properties from grids of detailed stellar models, capturing complex physical phases.

A multi-dimensional grid interpolation and mathematical modeling library written in Fortran with Python analysis tools. Translates tabular physical datasets into continuous functions, enhancing performance of downstream simulation tools.

Fortran Python Interpolation
Code →

Stroopwafel

Adaptive importance sampling algorithm for simulating rare binary stellar merger pathways. Significantly improves computational efficiency when exploring extreme regions of stellar parameter spaces.

An adaptive importance sampling and statistical inference engine. Solves the "rare-event simulation" problem by feeding back sampling statistics dynamically to focus computational resources on low-probability outcomes.

Statistics Sampling Algorithm
Code →

Bilby

Bayesian inference framework used by the LVK for gravitational-wave parameter estimation, compact-binary analyses, and low-latency inference workflows.

Open-source Python inference toolkit for scalable Bayesian analysis, nested sampling, reproducible workflows, and parameter estimation under complex physical models.

Python Bayesian Inference LVK
Code →
Research Output

Selected Publications

Selected peer-reviewed articles. See full bibliography via ORCID, Google Scholar, or NASA ADS.

2026

Strategy for identifying Vera C. Rubin Observatory kilonova candidates for targeted gravitational-wave searches

S. Stevenson, A. Moller, J. Powell

arXiv preprint

arXiv →
2026

Implications of Modern Mass-loss Rates for Massive Stars

J. D. Merritt, S. Stevenson, A. Sander, I. Mandel, J. Riley, B. Farr, L. A. C. van Son, T. Wagg, S. Vinciguerra, H. Jose

The Astrophysical Journal

📰 Recent work: We examine how updated stellar wind mass-loss prescriptions affect the formation of merging neutron stars and black holes.

DOI → arXiv →
2026

GWTC-5.0: Observations from the Second Part of the Fourth LIGO-Virgo-KAGRA Observing Run and Updates to the Gravitational-Wave Transient Catalog

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2026

GWTC-5.0: Methods for Identifying and Characterizing Gravitational-wave Transients

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2026

GWTC-5.0: Constraints on the Cosmic Expansion Rate and Modified Gravitational-wave Propagation

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2025

GW241011 and GW241110: Exploring Binary Formation and Fundamental Physics with Asymmetric, High-Spin Black Hole Coalescence

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2025

GW250114: testing Hawking's area law and the Kerr nature of black holes

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

Physical Review Letters

arXiv →
2025

GWTC-4.0: Updating the Gravitational-Wave Transient Catalog with Observations from the First Part of the Fourth LIGO-Virgo-KAGRA Observing Run

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2025

GWTC-4.0: Methods for Identifying and Characterizing Gravitational-wave Transients

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2025

GWTC-4.0: Constraints on the Cosmic Expansion Rate and Modified Gravitational-wave Propagation

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2025

GW231123: a Binary Black Hole Merger with Total Mass 190-265 M⊙

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration (including S. Stevenson)

arXiv preprint

arXiv →
2025

Rapid Stellar and Binary Population Synthesis with COMPAS: Methods Paper II

I. Mandel, J. Riley, A. Boesky, et al. (including S. Stevenson)

The Astrophysical Journal Supplement Series

DOI → arXiv →
2025

Formation of heavy double neutron stars I: Eddington-limited accretion for a 1.4 M⊙ neutron star at solar metallicity

A. Nair & S. Stevenson

Monthly Notices of the Royal Astronomical Society

DOI → arXiv →
2024

The High Time Resolution Universe Pulsar Survey-XIX. A coherent GPU accelerated reprocessing and the discovery of 71 pulsars in the Southern Galactic plane

R. Sengar, M. Bailes, V. Balakrishnan, et al. (including S. Stevenson)

arXiv preprint

arXiv →
2024

Binary population synthesis of the Galactic canonical pulsar population

Y. Song, S. Stevenson, D. Chattopadhyay, J. Tan, T. A. D. Paglione

Publications of the Astronomical Society of Australia

DOI → arXiv →
2023

Modelling stellar evolution in mass-transferring binaries and gravitational-wave progenitors with METISSE

P. Agrawal, J. Hurley, S. Stevenson, C. L. Rodriguez, D. Szecsi, A. Kemp

Monthly Notices of the Royal Astronomical Society, Volume 526, Issue 2

DOI → arXiv →
2023

Rapid localization and inference on compact binary coalescences with the Advanced LIGO-Virgo-KAGRA gravitational-wave detector network

S. Morisaki, R. Smith, L. Tsukada, S. Sachdev, S. Stevenson, C. Talbot, A. Zimmerman

Physical Review D, Volume 108, Issue 12

ADS → arXiv →
2022

Rapid stellar and binary population synthesis with COMPAS

Team COMPAS: J. Riley, P. Agrawal, J. W. Barrett, et al. (including S. Stevenson)

The Astrophysical Journal Supplement Series, Volume 258, Issue 2

DOI → arXiv →
2022

The High Time Resolution Universe Pulsar Survey -- XVII. PSR J1325-6253, a low eccentricity double neutron star system from an ultra-stripped supernova

R. Sengar, V. Balakrishnan, S. Stevenson, et al.

Monthly Notices of the Royal Astronomical Society

arXiv →
2022

Wide binary pulsars from electron-capture supernovae

S. Stevenson, R. Willcox, A. Vigna-Gomez, F. Broekgaarden

Monthly Notices of the Royal Astronomical Society

arXiv →
2022

Biases in Estimates of Black Hole Kicks from the Spin Distribution of Binary Black Holes

S. Stevenson

The Astrophysical Journal Letters, Volume 926, Issue 1

DOI → arXiv →
2022

Constraints on the contributions to the observed binary black hole population from individual evolutionary pathways in isolated binary evolution

S. Stevenson & T. A. Clarke

Monthly Notices of the Royal Astronomical Society

arXiv →
2022

Modelling the formation of the first two neutron star–black hole mergers, GW200105 and GW200115: metallicity, chirp masses, and merger remnant spins

D. Chattopadhyay, S. Stevenson, F. Broekgaarden, F. Antonini, K. Belczynski

Monthly Notices of the Royal Astronomical Society, Volume 512, Issue 4

DOI → arXiv →
2021

Impact of massive binary star and cosmic evolution on gravitational wave observations I: black hole–neutron star mergers

F. Broekgaarden, E. Berger, S. Stevenson, et al.

Monthly Notices of the Royal Astronomical Society, Volume 508, Issue 4

DOI → arXiv →
2020

Bayesian inference for compact binary coalescences with BILBY: Validation and application to the first LIGO-Virgo gravitational-wave transient catalogue

I. M. Romero-Shaw, C. Talbot, S. Biscoveanu, et al. (including S. Stevenson)

Monthly Notices of the Royal Astronomical Society, Volume 499, Issue 3

DOI → arXiv →
2020

Modelling Neutron Star-Black Hole Binaries: Future Pulsar Surveys and Gravitational Wave Detectors

D. Chattopadhyay, S. Stevenson, J. R. Hurley, M. Bailes, F. Broekgaarden

Monthly Notices of the Royal Astronomical Society

arXiv →
2020

The fates of massive stars: exploring uncertainties in stellar evolution with METISSE

P. Agrawal, J. Hurley, S. Stevenson, D. Szecsi, C. Flynn

Monthly Notices of the Royal Astronomical Society, Volume 497, Issue 4

ADS → arXiv →
2019

Modelling Double Neutron Stars: Radio and Gravitational Waves

D. Chattopadhyay, S. Stevenson, J. R. Hurley, L. J. Rossi, C. Flynn

Monthly Notices of the Royal Astronomical Society

arXiv →
2019

The impact of pair-instability mass loss on the binary black hole mass distribution

S. Stevenson, M. Sampson, J. Powell, A. Vigna-Gomez, C. J. Neijssel, D. Szecsi, I. Mandel

The Astrophysical Journal

arXiv →
2019

Stroopwafel: simulating rare outcomes from astrophysical populations, with application to gravitational-wave sources

F. Broekgaarden, L. Justin, S. Stevenson, et al.

Monthly Notices of the Royal Astronomical Society, Volume 490, Issue 4

DOI → arXiv →
2017

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration, including S. Stevenson)

Physical Review Letters, Volume 119

DOI → arXiv →
2017

Distinguishing Binary Black Hole Formation Channels with Gravitational Waves

W. M. Farr, S. Stevenson, et al.

Nature

DOI → arXiv →
2017

Formation of the first three gravitational-wave observations through isolated binary evolution

S. Stevenson, A. Vigna-Gomez, I. Mandel, J. W. Barrett, C. J. Neijssel, D. Perkins, S. E. de Mink

Nature Communications

arXiv →
2017

Hierarchical analysis of gravitational-wave measurements of binary black hole spin-orbit misalignments

S. Stevenson, C. P. L. Berry, I. Mandel

Monthly Notices of the Royal Astronomical Society

arXiv →
2016

Observation of Gravitational Waves from a Binary Black Hole Merger

B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration, including S. Stevenson)

Physical Review Letters, Volume 116

DOI → arXiv →
2015

Distinguishing compact binary population synthesis models using gravitational-wave observations of coalescing binary black holes

S. Stevenson, F. Ohme, S. Fairhurst

The Astrophysical Journal

arXiv →
Credentials

Curriculum Vitae

Brief timeline of academic and professional experience.

Professional Experience

2026 - Present
Adjunct Research Fellow
Swinburne University of Technology

Continuing gravitational-wave progenitor research, stellar population modelling, and collaboration across OzGrav and the LVK.

Continuing development of scientific simulation, analysis, and collaborative research software workflows.

2025 - 2026
OzGrav Senior Research Fellow
OzGrav Senior Research Fellow & Software Architect
Swinburne University of Technology

Led research projects on stellar population models, supervised PhD/Masters students, and co-developed core COMPAS modules.

Engineered Python-based statistical pipelines and distributed computing networks on HPC clusters to run simulation jobs at scale.

2022 - 2025
ARC DECRA Fellow
Swinburne University of Technology

Awarded a highly competitive Australian Research Council DECRA fellowship to research the origins of binary mergers.

Used statistical inference methods to compare population models against large gravitational-wave datasets.

2017 - 2022
OzGrav Postdoctoral Research Fellow
Swinburne University of Technology

Researched compact-object merger formation channels and contributed to binary population synthesis software.

Built and maintained open-source scientific code for large-scale Monte Carlo simulations on HPC systems.

2013 - 2017
PhD in Astrophysics
University of Birmingham, UK

Doctoral thesis: "Insights into binary black hole formation from gravitational waves".

Acquired solid background in scientific computing, differential equations, statistical Monte Carlo methods, and algorithm design.

Technical Expertise

Astrophysics

Stellar Evolution
Binary Interactions
Gravitational Waves

Research Skills

Student Supervision
Grant Writing
Academic Publishing

Languages

Python (pandas, NumPy)
C++ (OOP, STL)
Fortran
LaTeX
SQL & Git

Data Science / Math

Statistical Inference
High Performance Computing
Numerical Analysis

Tools & Communication

Scientific Writing
Public Speaking
Collaborative Dev
Office Productivity
AI-Assisted Workflows
Reach Out

Get In Touch

Feel free to message me regarding collaborations, job opportunities, or general queries.

Location

Melbourne, VIC, Australia

Affiliation

Swinburne University of Technology

Email

spstevenson@swin.edu.au