Multiband emission from pulsar wind nebulae: a possible injection spectrum

Abstract

<i>Aims. <i/>Recent research shows that particles with a spectrum of a relativistic Maxwellian plus a high-energy tail can be accelerated by relativistic collisionless shocks. We investigate the possibility of the high-energy particles with this new spectrum injected into pulsar wind nebulae (PWNe) from the terminate shock based on the study of multiwavelength emission from PWNe.<i>Methods. <i/>The dynamics of a supernova remnant (SNR) and multiband nonthermal emission from the PWN inside the remnant are investigated using a dynamical model with electrons/positrons injected with the new spectrum. In this model, the dynamical and radiative evolution of a pulsar wind nebula in a nonradiative supernova remnant can be described self-consistently.<i>Results. <i/>This model is applied to the three composite SNRs, G0.9+0.1, MSH 15-52, G338.3-0.0, and the multiband observed emission from the three PWNe is reproduced.<i>Conclusions. <i/>Our studies on the three remnants provide evidence of a new spectrum of the particles, which are accelerated by the terminate shock and injected into a PWN.