The kinematic Kelvin-Helmholtz instability-driven dynamo: implications for merging compact objects

@misc{beattie2026kinematic,
  title = {{The kinematic Kelvin-Helmholtz instability-driven dynamo: implications for merging compact objects}},
  author = {James R. Beattie and Amitava Bhattacharjee and Elias R. Most and Bart Ripperda and Alexander Philippov and Ralf S. Klessen and Salvatore Cielo},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2611.05880},
  eprint = {2611.05880},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2611.05880},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - The kinematic Kelvin-Helmholtz instability-driven dynamo: implications for merging compact objects
AU  - James R. Beattie
AU  - Amitava Bhattacharjee
AU  - Elias R. Most
AU  - Bart Ripperda
AU  - Alexander Philippov
AU  - Ralf S. Klessen
AU  - Salvatore Cielo
PY  - 2026
DA  - 2026/11/04
PB  - arXiv
DO  - 10.48550/arxiv.2611.05880
UR  - https://arxiv.org/abs/2611.05880
AB  - Binary neutron star (BNS) mergers excite a Kelvin--Helmholtz instability (KHI) in the shear layer between them. It is parasitized upon by the magnetic field to form a powerful magnetic dynamo. Using a large ensemble of high-resolution visco-resistive KHI-driven dynamo simulations we construct analytical, asymptotic in Reynolds number (Re) models for the magnetic field growth rates and mean vertical field dynamo onset times. Our models suggest that in the Re ≫ 1 limit, the mean vertical field is seeded immediately, kinematic growth rates become asymptotic in Re, and the dynamo moves out of the kinematic stage on 𝒪(0.1 ms) timescales, readily attaining magnetar-strength fields during this transition. This suggests that most global BNS merger simulations are not time-resolving the correct KHI-driven dynamo regime.
ER  -