|
|||||
|
|
A possible evolutionary track of pulsars |
|
| Institution: | Department of Geophysics, Beijing University China |
| Abstract: | It is usually assumed that the dipole radiation at the spin frequency Wd is the only source of braking torque on pulsars (the POG hypothesis), but certain observations cast doubt on this. In this paper, we discuss the effect of elctromagnetic braking near the light cylinder Wem without using the POG hypothesis. We found Wem ∝ P?3.2 (P is the pulsar period), and the total power Lt ∝ P?3.2 (if Lt ∝ Wem). A correlation analysis between Lt and Pn for a sample of 15 pulsars gives n = ?3.1, in agreement with our theoretical expectations.Our analysis based on observations shows that Wem is important or even dominant in some cases. In these cases, the evolutionary path (Fig.2) is very different from that given in /4/ where Wd is assumed to be dominant. The actual braking mechanism could be a superposition of the two (Fig.3).The gap in the diagram found by Ferguson /5/ for a sample of 80-odd pulsars persists in a larger sample of 199 pulsars. This gap, if real, implies that, for a certain range of parameter values, a neutron star is unstable, while it is stable on either side of the range. |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ | |