Author(s)

Chen Li, Cai Hongbing, Wang Kai, Zhang Yuxuan

Corresponding Author

Cai Hongbing

Abstract

Low-frequency turnover pulsars refer to pulsars that exhibit a spectral turnover near 100 MHz. To date, 82 pulsars with low-frequency turnover spectra have been discovered. The formation of this special type of radio spectrum is likely due to more intense free-free absorption in the interstellar medium at low frequencies. In this study, we explore and analyze the dispersion measure, peak frequency, period, and magnetic field strength of these pulsars. We find that the turnover frequencies of low-frequency turnover pulsars mainly range from 0.05 GHz to 0.2 GHz, and the average spectral index is -2.23. The dispersion measures of low-frequency turnover pulsars are mainly distributed between 0 and 50 pc cm-3, and there is no obvious correlation between the dispersion measure and period. However, there is a clear negative correlation between age and magnetic field strength, indicating that the magnetic field strength of low-frequency turnover pulsars will continuously decay with increasing age.

Keywords

pulsar, radio spectrum, radiation mechanism