# Plunging neutron stars as origin of organised magnetic field in galactic nuclei

## TL;DR

This paper explores the hypothesis that magnetized neutron stars drifting into galactic nuclei could supply organized magnetic fields to supermassive black holes, especially affecting lower-mass SMBHs.

## Contribution

It proposes a novel mechanism where neutron stars contribute dipole magnetic fields to SMBHs during close encounters or mergers.

## Key findings

- Neutron stars can deliver organized magnetic fields to SMBHs.
- The effect is more significant for lower-mass SMBHs.
- This mechanism could explain the large-scale magnetic fields observed near SMBHs.

## Abstract

Black holes cannot support their own internal magnetic field like, for example, compact stars can. Despite this fact observations indicate that event horizons of supermassive black holes (SMBH) are threaded by field lines along which plasma streams flow. Various magnetohydrodynamical mechanisms have been suggested to generate turbulent magnetic fields on small scales, however, the origin of the large-scale component is unclear. In this write-up we describe our progress in an on-going work and discuss the possibility of dipole-type magnetic fields being brought onto SMBH by magnetized neutron stars, which are expected to drift inward from a hidden population in the Nuclear Star Cluster. This can contribute to an organised component of the magnetic field on the characteristic length-scale of the stellar size, which thread the horizon during the final stages of the magnetized star plunge into or its close flyby around SMBH. Because of mass--size scaling relations for black holes, the effect is more important for lower-mass SMBH.