A study of the long-term flux density variation of PSRs B0329+54 and B1508+55
Department of Astronomy, Peking University, Beijing 100871, PR China e-mail: email@example.com
2 Urumqi Observatory,the National Astronomical Observatories, the Chinese Academy of Sciences, Urumqi 830011, PR China
3 Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, PR China
Accepted: 25 May 2004
We have observed the flux densities of PSRs B0329+54 and B1508+55 for 460 days at 327 MHz using the 25 m telescope of NAOC Urumqi Observatory. The flux density time series and the corresponding structure functions are presented. Our observational results at 327 MHz and other observations at 74 MHz and 610 MHz are compared with the predictions of the refractive scintillation theory. The frequency dependence of the refractive scintillation parameters for PSR B0329+54 has been investigated. The results show that the long-term flux density modulations of PSR B0329+54 at the three frequencies are best described by a Kolmogorov spectrum for electron density inhomogeneities. For PSR B1508+55, we suggest that the spectrum of the electron density fluctuation has a power exponent .
Key words: stars: pulsars: individual: PSR B0329+54, PSR B1508+55 / ISM: structure / plasmas / turbulence
© ESO, 2004