Exploring the intrabinary shock from the redback millisecond pulsar PSR J2129-0429

TL;DR

This study investigates the intrabinary shock emission from the redback millisecond pulsar PSR J2129-0429 using X-ray, UV, and gamma-ray observations, revealing orbital modulation in X-ray and UV but not in gamma-rays, and modeling the system's geometry.

Contribution

The paper provides the first detailed analysis of intrabinary shock emission in PSR J2129-0429, combining multi-wavelength data to model the system's geometry and emission mechanisms.

Findings

X-ray emission is non-thermal with a photon index of ~1.2.

Orbital modulation observed in X-ray and UV, but not in gamma-ray.

UV light curve modeling indicates a large viewing angle and negligible heating effect.

Abstract

We have investigated the intrabinary shock emission from the redback millisecond pulsar PSR J2129-0429 with XMM-Newton and Fermi. Orbital modulation in X-ray and UV can be clearly seen. Its X-ray modulation has a double-peak structure with a dip in between. The observed X-rays are non-thermal dominant which can be modeled by a power-law with a photon index of ~1.2. Intrabinary shock can be the origin of the observed X-rays. The UV light curve is resulted from the ellipsoidal modulation of the companion. Modeling the UV light curve prefers a large viewing angle. The heating effect of the UV light curve is found to be negligible which suggests the high energy radiation beam of PSR J2129-0429 does not direct toward its companion. On the other hand, no significant orbital modulation can be found in gamma-ray which suggests the majority of the gamma-rays come from the pulsar.