Broadband High-Energy Emissions of the Redback Millisecond Pulsar PSR J2129-0429

TL;DR

This study presents the first joint X-ray and gamma-ray analysis of the millisecond pulsar PSR J2129-0429, revealing its broadband emission, orbital modulation, and ruling out a pulsar wind nebula, advancing understanding of pulsar binary systems.

Contribution

It provides the first combined XMM-Newton and NuSTAR observations of PSR J2129-0429, modeling its broadband spectrum and orbital modulation with an intrabinary shock interaction.

Findings

X-ray emission detected up to 40 keV with a power-law spectrum.

Orbital period of 0.64 days with double-peaked modulation observed.

No pulsar wind nebula detected around PSR J2129-0429.

Abstract

We present the first results from a joint XMM-Newton and NuSTAR observation of the gamma-ray emitting millisecond pulsar compact binary PSR J2129-0429. X-ray emission up to about 40 keV is detected and the joint spectrum can be modeled with a power-law plus a neutron star atmosphere model. At a distance of 1.4 kpc, the 0.3-79 keV luminosity is $3.56\times10^{32}$ erg s$^{-1}$. We also detected the 0.64-day binary orbital period with a double-peaked structure across the wavebands. By combining the updated Fermi GeV data, we modeled the broadband spectral energy distribution as well as the X-ray modulation with an intrabinary model involving shock interaction between pulsar wind and outflow from the companion star. Lastly, we reported a high-resolution X-ray image provided by Chandra to rule out the proposed pulsar wind nebula associated with PSR J2129-0429.