Mass-Ratio Reversal as an Alternative to Hierarchical Mergers for GW241011
Abstract
Recent gravitational-wave (GW) observations have revealed binary black hole (BBH) mergers with both extreme mass ratios and large effective spin parameters (χeff). GW241011 is a notable example that shows these properties. Although hierarchical mergers (second-generation + first-generation BHs) can naturally produce high spins and become more prevalent than first-generation + first-generation mergers at mass ratios q ≲ 0.6, they are negligible at the extreme mass ratio ∼ 0.3 and are further limited by gravitational recoil kicks that can eject the second-generation BH from the host environment. Moreover, recent studies have argued against a dynamical origin for GW241011. Here, we investigate the formation of GW241011-like systems through the mass-ratio reversal (MRR) channel in isolated binary evolution. By quantifying the probability of producing such systems across a range of binary-evolution models, we identify the key dependencies on stellar-evolution and binary-interaction physics. Our results demonstrate the conditions under which the MRR channel can provide a viable alternative to hierarchical mergers for GW241011-like events, although its predicted merger rate density remains relatively low.
Versions
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BibTeX
@misc{hu2026massratio,
title = {{Mass-Ratio Reversal as an Alternative to Hierarchical Mergers for GW241011}},
author = {Rui-Chong Hu and Ying Qin and Bing Zhang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.27852},
eprint = {2606.27852},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.27852},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Mass-Ratio Reversal as an Alternative to Hierarchical Mergers for GW241011
AU - Rui-Chong Hu
AU - Ying Qin
AU - Bing Zhang
PY - 2026
DA - 2026/09/10
PB - arXiv
DO - 10.48550/arxiv.2606.27852
UR - https://arxiv.org/abs/2606.27852
AB - Recent gravitational-wave (GW) observations have revealed binary black hole (BBH) mergers with both extreme mass ratios and large effective spin parameters (χ_eff). GW241011 is a notable example that shows these properties. Although hierarchical mergers (second-generation + first-generation BHs) can naturally produce high spins and become more prevalent than first-generation + first-generation mergers at mass ratios q ≲ 0.6, they are negligible at the extreme mass ratio ∼ 0.3 and are further limited by gravitational recoil kicks that can eject the second-generation BH from the host environment. Moreover, recent studies have argued against a dynamical origin for GW241011. Here, we investigate the formation of GW241011-like systems through the mass-ratio reversal (MRR) channel in isolated binary evolution. By quantifying the probability of producing such systems across a range of binary-evolution models, we identify the key dependencies on stellar-evolution and binary-interaction physics. Our results demonstrate the conditions under which the MRR channel can provide a viable alternative to hierarchical mergers for GW241011-like events, although its predicted merger rate density remains relatively low.
ER -