paper

M51 ULX-7: super-orbital periodicity and constraints on the neutron star magnetic field

arXiv:1911.09670 · doi:10.1093/mnras/stz3298

Abstract

In the current work we explore the applicability of standard theoretical models of accretion to the observed properties of M51 ULX-7. The spin-up rate and observed X-ray luminosity are evidence of a neutron star with a surface magnetic field of G, rotating near equilibrium. Analysis of the X-ray light-curve of the system (Swift/XRT data) reveals the presence of a 39 d super-orbital period. We argue that the super-orbital periodicity is due to disc precession, and that material is accreted onto the neutron star at a constant rate throughout it. Moreover, by attributing this modulation to the free precession of the neutron star we estimate a surface magnetic field strength of G. The agreement of these two independent estimates provide strong constraints on the surface polar magnetic field strength of the neutron star.

11 pages, 6 figures, accepted for publication in MNRAS

References in corpus (26)

Cited by in corpus (3)

M51 ULX-7: super-orbital periodicity and constraints on the neutron star magnetic field · wovepaper