Speaker
Description
From the hundreds of gamma-ray pulsars known, only a handful show non-thermal X-ray pulsations. Instead, nine objects pulse in non-thermal X-rays but lack a counterpart at higher energies. What order parameters describe the spectral variety, making the pulsars GeV and/or X-ray bright? Can observations in only one portion of the spectra predict detectability in the other? Can we expect a population of MeV-peaking pulsars? We normally fit observational spectra just with phenomenological functions (a power law with a cutoff in gamma-rays, or a log parabola from X-rays up). Here we shall present the results of a relatively simple physical model for the magnetospheric emission of pulsars above 1 keV, with which we start tacking these questions. It is based on synchro-curvature emission, and includes 1D time-dependent particle propagation. The model seems to contain the basic ingredients needed to describe all observed spectra well: With just four physical parameters, we can fit gamma/X-ray pulsar spectra along seven orders of magnitude, providing an interpretation for the appearance of sub-exponential cutoffs at high energies, or the flattening of the X-ray spectra at soft energies.
