Shadow and intensities of charged dilatonic black hole in dilaton-massive gravity

In this work, we explore the shadow and intensity profiles of a recently developed charged dilatonic black hole in the framework of dilaton-massive gravity, using an infalling spherical accretion model. The dilaton-massive gravity theory introduces both a dilaton field and a mass term for gravitons, allowing us to investigate black hole behavior in the presence of scalar fields and massive gravity modifications. Our analysis reveals that these black holes exhibit varied horizon structures under certain parameter conditions, directly impacting their observable properties. Specifically, we find that dilaton-massive gravity parameters significantly influence the metric function, expanding the event horizon and thereby enlarging the black hole’s shadow. Interestingly, this expansion is accompanied by a noticeable decrease in surrounding observable intensities which is the consequence of the massive gravity effects on light propagation. The stronger gravitational field, driven by the dilaton and mass terms, enhances redshift effects, causing the observed light to lose more energy as it nears the black hole. These findings provide how modified gravity theories alter the optical appearance of black holes and could serve as observational markers for identifying deviations from classical gravity in high-resolution black hole imaging.