Bragg diffraction and the Iron crust of cold Neutron Stars

TL;DR

This paper proposes that X-ray diffraction by the iron crust of cold neutron stars could produce observable secondary peaks in X-ray signals, revealing the star's crystalline structure through Bragg diffraction effects.

Contribution

It introduces the idea that neutron star crusts can cause detectable X-ray diffraction patterns, providing a new method to study their internal composition.

Findings

Secondary X-ray peaks at specific wavelengths could indicate diffraction effects.

Observable diffraction signals depend on the intensity of the X-ray source and proximity of the neutron star.

Detection of diffraction peaks would confirm the crystalline nature of neutron star crusts.

Abstract

If cooled-down neutron stars have a thin atomic crystalline-iron crust, they must diffract X-rays of appropriate wavelength. If the diffracted beam is to be visible from Earth, the illuminating source must be very intense and near the reflecting star. An example is a binary system composed of two neutron stars in close orbit, one of them inert, the other an X-ray pulsar (perhaps an "anomalous" X-ray pulsar or magnetar, not powered by gas absorption from the companion or surrounding space, would be the cleanest example). The observable to be searched for is a secondary peak added (quasi-) periodically to the main X-ray pulse. The distinguishing feature of this secondary peak is that it appears at wavelengths related by simple integer numbers, lambda, lambda/2, lambda/3... lambda/n because of Bragg's diffraction law.