2025/01/28 by Niu, Shu, Yuan, Qiang, Zhang, Shui-Nai +3
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · doi:10.48550/arxiv.2501.17046
Extended very-high-energy γ-ray emission from middle-aged pulsars as revealed recently by several groundbased γ-ray experiments has strong implication on the transport of high-energy particles in the interstellar medium surrounding those pulsars. The γ-ray emission is widely believed to be produced by high-energy electrons and positrons accelerated by the pulsar wind nebulae when scattering off the interstellar radiation field via the inverse Compton process. Multiwavelength counterparts of the γ-ray halos are expected to be present, which are, however, not observed yet. In this work, we report for the first time the detection of extended X-ray emission from ∼ 0.2∘ radius region of PSR B0656+14 with eROSITA. The spectrum of the emission can be described by a power-law function with an index of ∼3.7. The fluxes decrease with radius faster than the prediction of the particle diffusion and synchrotron radiation in a uniform magnetic field, suggesting the existence of a radial gradient of the magnetic field strength as ∼ r-1. The magnetic field strength in the X-ray emitting region is constrained to be 4-10~μG.