A broadband X-ray study of the Rabbit pulsar wind nebula powered by PSR J1418-6058

TL;DR

This study presents a comprehensive broadband X-ray analysis of the Rabbit pulsar wind nebula, revealing its high-energy particle acceleration and potential as a Galactic PeVatron, through multi-instrument observations and spectral modeling.

Contribution

It provides the first detailed broadband X-ray spectral and spatial analysis of the Rabbit PWN, identifying its physical properties and high-energy particle acceleration capabilities.

Findings

Detected the pulsar's 110-ms spin period with NuSTAR.

Found the PWN extends up to ~20 keV with a photon index of ~2.

Indicated particles are accelerated to energies >500 TeV, making it a PeVatron candidate.

Abstract

We report on broadband X-ray properties of the Rabbit pulsar wind nebula (PWN) associated with the pulsar PSR J1418-6058 using archival Chandra and XMM-Newton data, and a new NuSTAR observation. NuSTAR data above 10 keV allowed us to detect the 110-ms spin period of the pulsar, characterize its hard X-ray pulse profile, and resolve hard X-ray emission from the PWN after removing contamination from the pulsar and other overlapping point sources. The extended PWN was detected up to $\sim$20 keV and is well described by a power-law model with a photon index $\Gamma\approx$2. The PWN shape does not vary significantly with energy, and its X-ray spectrum shows no clear evidence of softening away from the pulsar. We modeled the spatial profile of X-ray spectra and broadband spectral energy distribution in the radio to TeV band to infer the physical properties of the PWN. We found that a model with low magnetic field strength ($B\sim 10$ $\mu$G) and efficient diffusion ($D\sim 10^{27}$ cm$^2$ s$^{-1}$) fits the PWN data well. The extended hard X-ray and TeV emission, associated respectively with synchrotron radiation and inverse Compton scattering by relativistic electrons, suggests that particles are accelerated to very high energies ($\gtrsim500$ TeV), indicating that the Rabbit PWN is a Galactic PeVatron candidate.