Synchro-curvature emitting regions in high-energy pulsar models

TL;DR

This paper enhances a synchro-curvature radiation model for pulsars by improving particle injection treatment and computational efficiency, enabling better fits to observational data and insights into emission regions and candidate pulsars.

Contribution

The authors update the synchro-curvature model with improved particle injection handling and a fast minimization technique, allowing more efficient analysis of pulsar emission spectra.

Findings

Small spatial extent of high pitch angle particle trajectories

Synchrotron radiation is significant in gamma-ray pulsars

Identification of potential MeV-pulsar candidates J0357+3205 and J2055+2539

Abstract

The detected high-energy pulsars' population is growing in number, and thus, having agile and physically relevant codes to analyze it consistently is important. Here, we update our existing synchro-curvature radiation model by including a better treatment of the particle injection, particularly where the large pitch angle particles dominate the spectra, and by implementing a fast and accurate minimization technique. The latter allows a large improvement in computational cost, needed to test model enhancements and to apply the model to a larger pulsar population. We successfully fit the sample of pulsars with X-ray and $\gamma$-ray data. Our results indicate that, for every emitting particle, the spatial extent of their trajectory where the pitch angle is large and most of the detected X-ray radiation is produced is a small fraction of the light cylinder. We also confirm with this new approach that synchrotron radiation is not negligible for most of the gamma-ray pulsars detected. In addition, with the results obtained, we argue that J0357+3205 and J2055+2539 are MeV-pulsar candidates and are suggested for exhaustive observations in this energy band.