How to Form a Gravitational-Wave Source: Quantifying Intermediate Evolutionary Stages in Isolated Binary Stellar Evolution

Author

Ana Lam, CUNY Graduate CenterFollow

Date of Degree

9-2025

Document Type

Master's Thesis

Degree Name

Master of Science

Program

Astrophysics

Advisor

Floor Broekgaarden

Subject Categories

Other Astrophysics and Astronomy | Stars, Interstellar Medium and the Galaxy

Keywords

gravitational waves, massive stars, binaries

Abstract

Gravitational-wave (GW) detections from double compact object (DCO) mergers provide crucial observational constraints for understanding massive stars across cosmic time. Coupled with these observations, binary population synthesis simulations become powerful tools for probing the formation, evolution, and ultimate fates of their progenitors---massive binary stars. However, complex evolutionary pathways, shaped by key intermediate stages such as mass transfer phases and supernovae, present a significant challenge to assess their impact. To address this, we develop a framework to quantify the influence of intermediate evolutionary stages on GW sources. By combining Sankey diagrams with survival factors, we systematically investigate how intermediate stages influence DCO formation across isolated binary evolution channels. We find that the primary bottlenecks in forming merging DCOs are the common-envelope (CE) phase and the first supernova event. Survival rates vary significantly across model assumptions and the four formation channels: for the I) 'classic CE channel,' 21.4%--78% of systems remain bound after the first supernova and only 4.6%--37.6% survive the subsequent CE phase. For the II) 'only stable mass transfer channel,' 5%--17.9% of formed DCOs merge within a Hubble time. Lastly, in the III) 'single-core CE' and IV) 'double-core CE' channels, the first CE phase is the main bottleneck (survival rates range from 8.2%--35.9% and 0.4%--64.9% respectively). Our framework provides a tool to explore evolutionary stages that lead to DCO mergers and can, in the future, be paired with complementary observations to constrain models at intermediate stages.

Recommended Citation

Lam, Ana, "How to Form a Gravitational-Wave Source: Quantifying Intermediate Evolutionary Stages in Isolated Binary Stellar Evolution" (2025). CUNY Academic Works.
https://academicworks.cuny.edu/gc_etds/6482