Ilya Mandel developed advanced astrophysical modeling features and stability improvements for the TeamCOMPAS/COMPAS repository, focusing on binary star evolution and supernova physics. Over 11 months, he delivered enhancements such as refined mass transfer algorithms, improved wind mass-loss routines, and robust rotational velocity solvers, leveraging C++ and MATLAB for both simulation and post-processing. His work integrated new physical prescriptions, expanded configuration options, and introduced detailed data visualization tools, addressing both scientific accuracy and code maintainability. By systematically fixing bugs and updating documentation, Ilya ensured that the codebase remained reliable, reproducible, and adaptable for ongoing research and large-scale population synthesis.
October 2025 (TeamCOMPAS/COMPAS) focused on improving realism, configurability, and numerical robustness in astrophysical modeling. Delivered two high-impact features with extensive docs and configuration updates, stabilized core routines, and laid groundwork for reproducible research results.
October 2025 (TeamCOMPAS/COMPAS) focused on improving realism, configurability, and numerical robustness in astrophysical modeling. Delivered two high-impact features with extensive docs and configuration updates, stabilized core routines, and laid groundwork for reproducible research results.
Monthly summary for 2025-09 focusing on business value and technical achievements for TeamCOMPAS/COMPAS, highlighting delivered features, bug fixes, impact, and demonstrated skills.
Monthly summary for 2025-09 focusing on business value and technical achievements for TeamCOMPAS/COMPAS, highlighting delivered features, bug fixes, impact, and demonstrated skills.
In August 2025, delivered a key stability enhancement for the COMPAS mass-transfer workflow, focusing on the MALTSEV and Piersanti models. The fix refined handling of mass-transfer cases for stripped stars and ensured that CalculateEtaPTY outputs remain within a valid range. A version bump was included to reflect these changes, signaling improved reliability for downstream simulations. This work improves the trustworthiness of mass-transfer calculations used in critical population synthesis analyses and reduces the risk of invalid EtaPTY values propagating through analyses.
In August 2025, delivered a key stability enhancement for the COMPAS mass-transfer workflow, focusing on the MALTSEV and Piersanti models. The fix refined handling of mass-transfer cases for stripped stars and ensured that CalculateEtaPTY outputs remain within a valid range. A version bump was included to reflect these changes, signaling improved reliability for downstream simulations. This work improves the trustworthiness of mass-transfer calculations used in critical population synthesis analyses and reduces the risk of invalid EtaPTY values propagating through analyses.
July 2025 monthly summary for TeamCOMPAS/COMPAS: Delivered key physics enhancements, stability fixes, and code improvements that increase model fidelity, predictive power for merger rates and detection probabilities, and maintainability. Highlights include MATLAB integration with Cosmic History outputs, enhanced CHE modeling with two-stage CE options, refined Muller-Mandel kick handling, mass transfer improvements with debugging instrumentation, plotting enhancements to exclude mergers and ensure correct polymorphism, and codebase refactoring for header organization.
July 2025 monthly summary for TeamCOMPAS/COMPAS: Delivered key physics enhancements, stability fixes, and code improvements that increase model fidelity, predictive power for merger rates and detection probabilities, and maintainability. Highlights include MATLAB integration with Cosmic History outputs, enhanced CHE modeling with two-stage CE options, refined Muller-Mandel kick handling, mass transfer improvements with debugging instrumentation, plotting enhancements to exclude mergers and ensure correct polymorphism, and codebase refactoring for header organization.
June 2025 — TeamCOMPAS/COMPAS delivered core research tooling, stability improvements, and visualization enhancements that elevate modeling realism, monitoring, and maintainability. Key achievements include the Cosmic History Integrator (MATLAB tooling for BSE/SSE outputs) enabling merger-rate tracking and cosmic-time visualization; SN kick distribution updates aligned with Disberg & Mandel 2025 (including a log-normal option, kick caps, and refactored drawing utilities); visualization enhancements with logarithmic scaling for DWD plots and new binary-evolution comparison plots; improved stellar-evolution core mass classification to reliably distinguish ECSN from CCSN using threshold-based, on-the-fly computations; and a TPAGB supernova explosions bug fix ensuring core-collapse occurs only under correct physical conditions. Documentation and stability updates accompany these changes to improve maintainability and reduce technical debt. Overall, these efforts increase modeling accuracy, shorten research cycles, and improve communication of results to stakeholders.
June 2025 — TeamCOMPAS/COMPAS delivered core research tooling, stability improvements, and visualization enhancements that elevate modeling realism, monitoring, and maintainability. Key achievements include the Cosmic History Integrator (MATLAB tooling for BSE/SSE outputs) enabling merger-rate tracking and cosmic-time visualization; SN kick distribution updates aligned with Disberg & Mandel 2025 (including a log-normal option, kick caps, and refactored drawing utilities); visualization enhancements with logarithmic scaling for DWD plots and new binary-evolution comparison plots; improved stellar-evolution core mass classification to reliably distinguish ECSN from CCSN using threshold-based, on-the-fly computations; and a TPAGB supernova explosions bug fix ensuring core-collapse occurs only under correct physical conditions. Documentation and stability updates accompany these changes to improve maintainability and reduce technical debt. Overall, these efforts increase modeling accuracy, shorten research cycles, and improve communication of results to stakeholders.
May 2025: Delivered features, reliability fixes, and documentation improvements for TeamCOMPAS/COMPAS, delivering faster data analysis, more robust physical modeling, and clearer defaults. Key outcomes include Matlab plotting and post-processing enhancements with code cleanup and positivity constraints on Loveridge Lambdas; SSE Switch log improvements for better observability; default configurations and documentation updates to streamline onboarding; targeted bug fixes that address critical modeling issues (issue #1380, GiantBranch radial extent, remnant donor mass ratios); and expanded modeling capabilities in Convective Envelopes and White Dwarfs, including unit conversions and updates, plus implementation of Jeff's suggested change. These efforts reduced post-processing time, improved numerical stability, and enhanced maintainability and documentation.
May 2025: Delivered features, reliability fixes, and documentation improvements for TeamCOMPAS/COMPAS, delivering faster data analysis, more robust physical modeling, and clearer defaults. Key outcomes include Matlab plotting and post-processing enhancements with code cleanup and positivity constraints on Loveridge Lambdas; SSE Switch log improvements for better observability; default configurations and documentation updates to streamline onboarding; targeted bug fixes that address critical modeling issues (issue #1380, GiantBranch radial extent, remnant donor mass ratios); and expanded modeling capabilities in Convective Envelopes and White Dwarfs, including unit conversions and updates, plus implementation of Jeff's suggested change. These efforts reduced post-processing time, improved numerical stability, and enhanced maintainability and documentation.
April 2025 monthly summary for TeamCOMPAS/COMPAS focusing on delivering higher accuracy in stellar angular momentum calculations, richer SSE output, and clearer debugging guidance. Key improvements include a refactor to use OmegaBreak() for Keplerian frequency calculations, addition of OMEGA and OMEGA_BREAK fields in SSE output, and documentation clarification for --timestep-multiplier. These changes enhance simulation fidelity, data richness, and developer usability, supporting better decision making and faster iteration.
April 2025 monthly summary for TeamCOMPAS/COMPAS focusing on delivering higher accuracy in stellar angular momentum calculations, richer SSE output, and clearer debugging guidance. Key improvements include a refactor to use OmegaBreak() for Keplerian frequency calculations, addition of OMEGA and OMEGA_BREAK fields in SSE output, and documentation clarification for --timestep-multiplier. These changes enhance simulation fidelity, data richness, and developer usability, supporting better decision making and faster iteration.
March 2025 monthly summary for TeamCOMPAS/COMPAS: Implemented stability-focused wind mass-loss improvements with a capped rate and time-step aware calculation to improve convergence and accuracy in both single and binary evolution; included release-note updates and robustness fixes for non-positive values and division-by-zero in timestep calculations. Introduced a Keplerian rotation limit for mass-gaining stars in binary mass transfer with configurable responses to super-critical spin-up, enhancing spin-up safety and configurability. Strengthened envelope modeling robustness with on-demand lambda calculations and refined Loveridge lambda handling, plus fixes to envelope-type binding-energy logic and edge-case handling. Added a convective-envelope-mass-threshold criterion with a user-facing option to improve modeling accuracy. Improved config, error handling, and documentation across initialization, inputs validation, version strings, and YAML parsing utilities, reducing debugging time and increasing maintainability.
March 2025 monthly summary for TeamCOMPAS/COMPAS: Implemented stability-focused wind mass-loss improvements with a capped rate and time-step aware calculation to improve convergence and accuracy in both single and binary evolution; included release-note updates and robustness fixes for non-positive values and division-by-zero in timestep calculations. Introduced a Keplerian rotation limit for mass-gaining stars in binary mass transfer with configurable responses to super-critical spin-up, enhancing spin-up safety and configurability. Strengthened envelope modeling robustness with on-demand lambda calculations and refined Loveridge lambda handling, plus fixes to envelope-type binding-energy logic and edge-case handling. Added a convective-envelope-mass-threshold criterion with a user-facing option to improve modeling accuracy. Improved config, error handling, and documentation across initialization, inputs validation, version strings, and YAML parsing utilities, reducing debugging time and increasing maintainability.
February 2025 monthly summary for TeamCOMPAS/COMPAS. Delivered naming harmonization for the PPISN prescription by renaming to WOOSLEY across code, documentation, and type definitions, with deprecation notices and updated changelog/docs referencing the new name. Enhanced PPISN event visualization through plotter refinements (detailed evolution plotter): adjusted image counts, introduced a rotate_image flag, and improved plotting of event merging times. Extended the mass transfer model to consider nuclear timescale MT for evolved donors and updated Zeta equilibrium behavior across evolution phases. Implemented a comprehensive set of bug fixes and maintenance improvements addressing mass transfer and radius calculations, convective envelope mass handling, binding energy usage, function call parameters, and timestep handling, along with warnings suppression and convergence improvements. These changes increase model fidelity, plotting usability, and numerical stability, delivering business value through clearer nomenclature, actionable visual analysis, and more accurate long-term evolution predictions.
February 2025 monthly summary for TeamCOMPAS/COMPAS. Delivered naming harmonization for the PPISN prescription by renaming to WOOSLEY across code, documentation, and type definitions, with deprecation notices and updated changelog/docs referencing the new name. Enhanced PPISN event visualization through plotter refinements (detailed evolution plotter): adjusted image counts, introduced a rotate_image flag, and improved plotting of event merging times. Extended the mass transfer model to consider nuclear timescale MT for evolved donors and updated Zeta equilibrium behavior across evolution phases. Implemented a comprehensive set of bug fixes and maintenance improvements addressing mass transfer and radius calculations, convective envelope mass handling, binding energy usage, function call parameters, and timestep handling, along with warnings suppression and convergence improvements. These changes increase model fidelity, plotting usability, and numerical stability, delivering business value through clearer nomenclature, actionable visual analysis, and more accurate long-term evolution predictions.
December 2024: Delivered critical physics corrections and documentation improvements for TeamCOMPAS/COMPAS. Key work included preserving the product a*M during wind mass loss, refining ECSN decision logic in binary evolution, and correcting the mass-transfer-fa option description. Debugging outputs were added to verify calculations and changes are tracked via explicit commits to support validation and future maintenance. These changes improve model fidelity and reduce the risk of incorrect evolutionary outcomes, enabling more reliable binary-star predictions for planning and risk assessment.
December 2024: Delivered critical physics corrections and documentation improvements for TeamCOMPAS/COMPAS. Key work included preserving the product a*M during wind mass loss, refining ECSN decision logic in binary evolution, and correcting the mass-transfer-fa option description. Debugging outputs were added to verify calculations and changes are tracked via explicit commits to support validation and future maintenance. These changes improve model fidelity and reduce the risk of incorrect evolutionary outcomes, enabling more reliable binary-star predictions for planning and risk assessment.
November 2024 — Delivered targeted physics improvements for TeamCOMPAS/COMPAS and a broad bug-fix sweep, boosting simulation fidelity, resilience, and release readiness. Notable feature deliveries include: stellar rotation enhancement, enhanced angular momentum loss during mass loss, a significant update to core modeling and simulations, using core radii to determine common envelope (CE) survival, and recalculation of stellar evolution timescales after mass loss. A parallel bug-fix program addressed compilation issues, rotation initialization and unit problems, code cleanliness, and output hygiene, with critical fixes around Chandrasekhar mass checks, CE merger handling, McBGB guards, and general batch stability. These changes improved physical fidelity, reduced risk of incorrect CE outcomes, enhanced maintainability, and supported clearer release notes for batch deployments. Technologies demonstrated include advanced stellar physics modeling, robust code hygiene, and documentation/release engineering.
November 2024 — Delivered targeted physics improvements for TeamCOMPAS/COMPAS and a broad bug-fix sweep, boosting simulation fidelity, resilience, and release readiness. Notable feature deliveries include: stellar rotation enhancement, enhanced angular momentum loss during mass loss, a significant update to core modeling and simulations, using core radii to determine common envelope (CE) survival, and recalculation of stellar evolution timescales after mass loss. A parallel bug-fix program addressed compilation issues, rotation initialization and unit problems, code cleanliness, and output hygiene, with critical fixes around Chandrasekhar mass checks, CE merger handling, McBGB guards, and general batch stability. These changes improved physical fidelity, reduced risk of incorrect CE outcomes, enhanced maintainability, and supported clearer release notes for batch deployments. Technologies demonstrated include advanced stellar physics modeling, robust code hygiene, and documentation/release engineering.
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