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This content will become publicly available on June 19, 2026

Title: Intermediate Mass Ratio Inspirals in Milky Way Galaxies
Abstract A consequence of a nonzero occupation fraction of massive black holes (MBHs) in dwarf galaxies is that these MBHs can become residents of larger galaxy halos via hierarchical merging and tidal stripping. Depending on the parameters of their orbits and original hosts, some of these MBHs will merge with the central supermassive black hole in the larger galaxy. We examine four cosmological zoom-in simulations of Milky Way-like galaxies to study the demographics of the black hole mergers that originate from dwarf galaxies. Approximately half of these mergers have mass ratios less than 0.04, which we categorize as intermediate mass ratio inspirals, or IMRIs. Inspiral durations range from 0.5–8 Gyr, depending on the compactness of the dwarf galaxy. Approximately half of the inspirals may become more circular with time, while the eccentricity of the remainder does not evolve. Overall, IMRIs in Milky Way-like galaxies are a significant class of black hole mergers that can be detected by LISA, and must be prioritized for waveform modeling.  more » « less
Award ID(s):
2107764
PAR ID:
10635364
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Astrophysical Journal
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
986
Issue:
2
ISSN:
0004-637X
Page Range / eLocation ID:
208
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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