On the unusually large spatial extent of the TeV nebula HESS J1825−137: implication from the energy-dependent morphology. Issue 2 (13th April 2020)

• Record Type: Journal Article
• Authors: Liu, Ruo-Yu; Yan, Huirong
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 494:Issue 2(2020)
• Page Start: 2618
• Page End: 2627
• Publication Date: 2020-04-13
• Subjects: diffusion -- radiation mechanisms: non-thermal -- pulsars: individual: HESS J1825−137 -- gamma-rays: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa911
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Deep observation of the High Energy Stereoscopic System (HESS) on the most extended pulsar wind nebula HESS J1825−137 reveals an enhanced energy-dependent morphology, providing useful information on the particle transport mechanism in the nebula. We find that the energy-dependent morphology is consistent with a diffusion-dominated transport of electrons/positrons. It provides an alternative possible interpretation for the unusually large spatial extent (i.e. ${\gtrsim} 100$ pc) of the nebula, which could then be attributed to the diffusion of escaping electrons/positrons from a compact plerion. The influence of various model parameters on the energy-dependent extent of the nebula is studied in the diffusion-dominated scenario. We also show that the energy-dependent morphology of the nebula may also be used to study the spin-down history of the pulsar.