Understanding formation and properties of gravitational waves events from galactic nuclei

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K13914
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: The University of Tokyo
• Principal Investigator: Trani Alessandro 東京大学, 大学院理学系研究科(理学部), 客員共同研究員 (20881543)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: Gravitational waves / Gravity / Dynamics / Active galactic nuclei

Outline of Final Research Achievements

This project made great progress at predicting the formation and evolution of gravitational wave sources in galactic nuclei. We first published a series of studies on the stability of triple systems. This also allowed us to produce predictions of gravitational wave mergers from triple systems with compact objects in stellar clusters. Related research included investigating the repeated mergers of compact object in galactic nuclei, using an innovative Monte-Carlo/N-body scheme. We then investigated the impact of three-body encounters around supermassive black holes, revealing the eccentricity that such sources may have within the LIGO-Virgo-KAGRA band at design sensitivity. Additionally we developed and published the first 1-dimensional active galactic nuclei modeling package, which enabled the modeling of active galactic nuclei properties, essential for understanding the impact on the embedded black hole population.

Free Research Field

Astrophysics

Academic Significance and Societal Importance of the Research Achievements

This project made advances on the formation of gravitational wave sources, which were detected in 2015 and whose origin is still unknown. Through the use of numerical and analytical models, we put constraints on the properties and merger rates of gravitational wave mergers from black hole binaries.