The 2009 Fermi Symposium

The Multi-faceted Synergy between X-ray and Gamma-ray Astronomies

Patrizia A. Caraveo

Abstract:

To optimize the timing parameters of gamma-ray only pulsars, accurate positions are highly desirable. Given the .me span covered by gamma-ray observations, the photon phasing procedure is very sensitive to the source position used to correct the photon arrival times to the solar system barycenter. A rough or inaccurate position, likely to affect faint gamma-ray sources, will hamper the accuracy of the photon phasing, making it difficult to detect (or to confirm) the source .ming signature. X-ray observations are an effective tool to single out pulsar candidate counterparts whose coordinates can be tested through the gamma-ray .ming analysis. The right position will improve the phasing accuracy, thus increasing the significance of the pulsation detection. Archival data, as well as freshly acquired ones have been used to secure the .ming signature detection of a large fraction of the Fermi gamma-ray only pulsars. The high number of such pulsars detected by Fermi has fostered a growing synergy between X and gamma-ray observations with the SWIFT observatory playing a major role. Deeper observations with high throughput instruments, such as XMM-Newton, Chandra or Suzaku, remain of paramount importance in order to understand the source physics.