Pulsed optical emission by radio pulsars

The luminosity L of radio pulsars due to synchrotron radiation by the prima ry beam at the magnetosphere periphery is derived. There is a strong correl ation between the observed optical luminosities of radio pulsars and the pa rameter P(overdot)/P-4 (where P is the pulsar period). This correlation pre dicts appreciable optical emission from several dozen pulsars, in particula r, from all those with P < 0.1 s. Agreement with optical observations can b e achieved for Lorentz factors of the secondary plasma gamma (p) = 2-13. Pl asma with such energies can be produced only when the magnetic-field struct ure near the neutron-star surface deviates substantially from a dipolar fie ld. The peak frequency of the synchrotron spectrum should shift toward high er values as the pulsar period P decreases this is, in agreement with obser vational data for 27 radio pulsars for which emission has been detected out side the radio band. (C) 2001 MAIK " Nauka/lnterperiodica".