Cyclotron lines in X-ray pulsars as a probe of relativistic plasmas in   superstrong magnetic fields
  The systematic search for the presence of cyclotron lines in the spectra of accreting X-ray pulsars is being carried on with the BeppoSAX satellite since the beginning of the mission. These highly successful observations allowed the detection of cyclotron lines in many of the accreting X-ray pulsars observed. Some correlations between the different measured parameters were found. We present these correlations and discuss them in the framework of the current theoretical scenario for the X-ray emission from these sources. 
D. Dal Fiume (1), Filippo Frontera (2), Nicola Masetti (1), Mauro   Orlandini(1), Eliana Palazzi(1), Stefano Del Sordo(3), A...