Probing the radio to X-ray connection of the Vela X PWN with Fermi LAT and t H.E.S.S

Oct, 2008
11 pages
Published in:
  • Astrophys.J.Lett. 689 (2008) L125
e-Print:

Citations per year

200920132017202120250123456
Abstract: (arXiv)
Morphologically it appears as if the Vela X PWN consists of two emission regions: whereas X-ray (1 keV) and very high energy (VHE) H.E.S.S. gamma-ray observations appear to define a cocoon type shape south of the pulsar, radio observations reveal an extended area of size 2 deg by 3 deg (including the cocoon area), also south of the Vela pulsar. Since no wide field of view (FoV) observations of the synchrotron emission between radio and X-rays are available, we do not know how the lepton (e+/-) spectra of these two components connect and how the morphology changes with energy. Currently we find that two distinct lepton spectra describe the respective radio and X-ray/VHE gamma-ray spectra, with a field strength of 5 muG self-consistently describing a radiation spectral break (or energy maximum) in the multi-TeV domain as observed by H.E.S.S. (if interpreted as IC radiation), while predicting the total hard X-ray flux above 20 keV (measured by the wide FoV INTEGRAL instrument) within a factor of two. If this same field strength is also representative of the radio structure (including filaments), the implied IC component corresponding to the highest radio frequencies should reveal a relatively bright high energy gamma-ray structure and Fermi LAT should be able to resolve it. A higher field strength in the filaments would however imply fewer leptons in Vela X and hence a fainter Fermi LAT signal.
  • pulsars: individual (Vela X)
  • Radiation mechanisms: nonthermal
  • ISM: jets and outflows
  • ISM: supernova remnants
  • gamma rays: theory
  • gamma ray: VHE
  • X-ray
  • radio wave
  • pulsar
  • lepton: energy spectrum