Overview This repository contains the complete research framework, manuscript source files, supplementary research chronicle, and reproducibility package associated with the investigation of chemical enrichment histories and halo-related baryon partitioning in cosmological galaxy simulations. Using data from the IllustrisTNG project, the study examines whether present-day galaxy observables retain measurable information about long-term assembly histories and the coupled evolution of baryonic and dark-matter components. The central finding is that stellar metallicity emerges as a robust observable indicator of halo-related baryon partitioning, even after controlling for conventional baryonic scaling relations. Scientific Framework The investigation was conducted in two major phases. Discovery Phase (TNG100-1) Using reconstructed galaxy histories from the IllustrisTNG100-1 simulation, a series of entropy-inspired and information-inspired compact descriptors were developed to characterize galaxy structure, chemical enrichment, and evolutionary state. Multiple complementary analytical approaches were employed, including: Random Forest regression Principal Component Analysis (PCA) Residual analyses Mass-matched statistical controls Evolutionary history reconstruction Across these analyses, stellar metallicity consistently emerged as the strongest predictor of the halo-related baryon partitioning target identified in this study. Independent Validation Phase (TNG50-1) The metallicity-partitioning relation was subsequently evaluated using an independent sample of 500 galaxies from the higher-resolution IllustrisTNG50-1 simulation. The relation persisted across stellar-mass bins and remained detectable after residualization against conventional baryonic observables, providing an independent validation of the primary discovery. Evolutionary Interpretation Main Progenitor Branch (MPB) histories revealed systematic differences between systems that ultimately evolve toward low-partitioning and high-partitioning states. Low-partitioning systems typically exhibit rapid early enrichment and earlier chemical maturation, whereas high-partitioning systems show more sustained late-time gas growth and delayed enrichment pathways. These results suggest that present-day stellar metallicity may function as a fossil record of galaxy assembly timing and long-term gas-regulation processes. Supplementary Research Chronicle The repository includes a comprehensive Supplementary Research Chronicle documenting the complete development history of the project. Rather than presenting only the final successful pathway, the chronicle preserves the full sequence of investigations, including exploratory analyses, negative results, methodological pivots, validation campaigns, and intermediate findings. Documented stages include: SPARC rotation-curve analyses LITTLE THINGS neutral-hydrogen investigations DDO154 case-study analyses Entropy-descriptor development TNG100 discovery analyses Robustness campaigns Independent TNG50 validation Evolutionary history reconstruction The supplement therefore provides a transparent record of how the final scientific conclusions emerged from the broader research process. Reproducibility In accordance with open-science principles, the repository contains a scripted reproducibility framework designed to regenerate the published outputs from the included datasets and cached history products. The reproducibility package includes: Automated execution scripts (run.sh) Analysis and validation code Processed data products Cached history tables Figure-generation scripts Manuscript source files Supplementary documentation The repository is designed to support independent verification of the complete published analysis workflow from the included data products, including figure generation, statistical testing, validation procedures, and manuscript compilation. Repository Contents The repository contains: Main manuscript (main.pdf) Supplementary Research Chronicle (supplement.pdf) Complete manuscript source files Analysis scripts Validation scripts Figure-generation pipeline Processed datasets Cached evolutionary histories Reproducibility framework Supporting documentation Author Mustafa BabayigitIndependent Researcher, Belgium ORCID: https://orcid.org/0009-0006-2933-281XEmail: mustafa.babayigit@outlook.beWebsite: https://irmustafababayigit.github.io
Mustafa Babayigit (Mon,) studied this question.