Frequency Evolution Behavior of Pulse Profile of PSR B1737+13 with the Inverse Compton Scattering Model

The radio radiation mechanism is one of the open questions in pulsar physics. Multiband observations are very important for constraining the pulsar radiation mechanism. In this paper, we investigate the pulse profiles of PSR B1737+13 and its evolution with the frequency. The integrated pulse profiles are obtained from the European Pulsar Network and the Australia Telescope National Facility data, together with recent observations from the largest dish Five-hundred-meter Aperture Spherical radio Telescope. The radiation components are separated with the squared hyperbolic secant functions, and the radiation altitudes of each radiation component at different frequencies are calculated. It is found that the radio radiation at different frequencies comes from different altitudes. The frequency evolutions of separations for the inner and outer cone components are studied. It is found that the separations of the inner and outer cone components have opposite frequency dependence. We simulate the RFM of PSR B1737+13 with the inverse Compton scattering (ICS) model and find that the RFM can be naturally described by the ICS model. Through the simulation, the radio radiation region of PSR B1737+13 is determined, and the result shows that the radio radiation of this pulsar may be generated in the annular gap region.