Unidentified Galactic High-Energy Sources as Ancient Pulsar Wind Nebulae in the light of new high energy observations and the new code

摘要

In a Pulsar Wind Nebula (PWN), the lifetime of inverse Compton (IC) emittingelectrons exceeds the lifetime of its progenitor pulsar (as well as itsshell-type remnant), but it also exceeds the age of those that emit viasynchrotron radiation. Therefore, during its evolution, the PWN can remainbright in IC so that its GeV-TeV gamma-ray flux remains high for timescalesmuch larger (for 10^5 - 10^6 yrs) than the pulsar lifetime and the X-ray PWNlifetime. In this scenario, the magnetic field in the cavity induced by thewind of the progenitor star plays a crucial role. This scenario is in line withthe discovery of several unidentified or "dark" sources in the TeV gamma-rayband without X-ray counterparts; and it is also finding confirmation in therecent discoveries at GeV gamma rays. Moreover, these consequences could bealso important for reinterpreting the detection of starburst galaxies in theTeV gamma-ray band when considering a leptonic origin of the gamma-ray signal.Both theoretical aspects and their observational proofs will be discussed, aswell as the first results of our new modeling code.