On the simultaneous generation of radio and soft X-ray emission by AXP 4U 0142+61

TL;DR

This paper explores how quasi-linear diffusion in the magnetosphere of AXP 4U 0142+61 can simultaneously generate radio waves and soft X-ray emission, linking plasma processes to observed emissions.

Contribution

It proposes a model where QLD causes simultaneous radio and soft X-ray emission in AXP 4U 0142+61, connecting plasma physics to observational phenomena.

Findings

QLD can produce radio waves at 40-111 MHz.

The model links soft X-ray energies 0.3-1.4 keV with radio emission.

Magnetospheric plasma parameters support the proposed mechanism.

Abstract

In the present paper we study the possibility of a simultaneous generation of radio waves and soft $X$-rays by means of the quasi-linear diffusion (QLD) in the anomalous pulsar AXP 4U 0142+61. Considering the magnetosphere composed of the so-called beam component and the plasma component respectively, we argue that the frozen-in condition will inevitably lead to the generation of the unstable cyclotron waves. These waves, via the QLD, will in turn influence the particle distribution function, leading to certain values of the pitch angles, thus to an efficient synchrotron mechanism, producing soft $X$-ray photons. We show that for physically reasonable parameters of magnetospheric plasmas, the QLD can provide generation of radio waves in the following interval $40$ MHz-$111$ MHz connected to soft $X$-rays for the domain $0.3$keV-$1.4$keV.