Origin of magnetars in binary systems

TL;DR

This paper reviews how magnetars can form in binary systems through progenitor spin-up, discusses potential accreting magnetar candidates, and suggests new models can explain their properties without requiring extremely strong magnetic fields.

Contribution

It introduces new accretion models that account for magnetar properties in binary systems without necessitating ultra-strong magnetic fields.

Findings

Most magnetars are isolated, but some binaries may host accreting magnetars.

New models can explain observed properties without large magnetic fields.

Binary evolution pathways can produce magnetar-like objects.

Abstract

I review several scenarios of magnetar formation in binary systems via spin-up of a progenitor due to interaction with its companion. Mostly, these evolutionary channels lead to formation of isolated magnetars, and indeed, all well-established sources of this class are single objects. However, some binaries can survive, and several candidates to accreting magnetars have been proposed. I discuss this issue, and conclude that new accretion models can explain properties of the proposed candidates without large magnetic field in correspondence with models of magnetic field evolution.