Fermi Gamma-ray Space Telescope

What Fermi does and does not tell us about pulsar emission mechanism(s)

A. N. Timokhin

Abstract:

Fermi provides us a wealth of information about pulsar gamma-ray emission. We know that the bulk of this emission is emitted in the outer parts of the magnetosphere and that some pulsars are quite efficient in conversion of rotational energy into radiation. These and other properties of pulsar emission pose serious challenges to standard pulsar models. Despite remarkable progress achieved in the last 15 years in theoretical understanding of physical processes at play in pulsar magnetospheres we still do not have clear answer to the most fundamental questions about the origin of pulsar emission - we do not know what is the process(es) responsible for the emission, where exactly in the magnetosphere are emitting regions, where the bulk of the plasma filling the magnetosphere is produced. In this talk I will give a brief overview of the state of theoretical efforts dedicated to modeling pulsar magnetospheres and constrains imposed by observational data on those models. I will discuss how existing contradictions might be resolved and what new types of observations might significantly improve the chances to solve the five decades old problem of pulsar emission mechanism(s).