The feature of shadow images and observed luminosity of the Bardeen black hole surrounded by different accretions.

By exploring the photon motion in the region near the Bardeen black hole, the shadow and luminosity of the black hole surrounded by different accretions are studied in this paper. We analyzed the changes in shadow imaging and observation luminosity when the relevant physical parameters are changed. In the static and infalling spherical accretion, although the radius of the shadow and the position of the photon spheres do not change in the two models, the observation intensity of the black hole with infalling accretion is significantly lower than that of the static accretion. In particular, in the case of the thin disk accretion, we study the contribution of the photon rings, lensing rings and direct emission to the total observed flux. The result shows that the observed brightness of black holes is mainly determined by direct emission. Furthermore, in the different forms of the emission modes, the lensing ring will provide a small part of the observation flux, while the photon ring can provide a negligible observation flux. After that, we compare our results with the Schwarzschild black hole, we find that the existence or change of the parameter $g$ will greatly affect the imaging and observation intensity of black hole shadow. Hence, the parameter $g$ change the spacetime structure which affects the photon sphere, the deflection angle and the observations of black hole shadows.