On the Nature of Pulsars. I. Theory
Abstract
We present in this paper the initial installment of a quantitative exploration of one particular pulsar model. We first make plausible and then assume that the seat of the pulsar phenomenon is a rotating neutron star having a dipolar magnetic field which is not parallel to the rotation axis. We then show that such stars may be expected to emit large amounts (1050_1052 ergs) of magnetic-dipole and gravitational- quadrupole radiation, that these energy losses are inevitably associated with losses of angular momentum and increases in the rotation periods, and that the emitted low-frequency magnetic-dipole radiation is extremely efficient at accelerating charged particles to relativistic energies. An explicit expression for the period as a function of time allows us to calculate the age of the Crab Nebula (with 20 percent accuracy) and to predict the so far unobserved second derivative of the period (d2P/dt2). We also de- termine the luminosity of the nebula and the highest-energy electrons presently being injected into it- both numbers found to be in good agreement with independent observations. In extreme cases the ac- celeration mechanism can produce protons with energies up to m~c2(e2/Gm~)'/3 or 1021 eV, which is somewhat in excess of the most energetic cosmic rays yet observed. The theory predicts a relation be- tween period, F, and rate of change of period, dP/dt 3 X 10'5/P(sec), which is well observed, in the mean, for pulsars. Finally, after determining the magnetic decay time to be about 4 million years, we predict that few pulsars should be found with periods in excess of 1.5 seconds, also in good accord with observations. We do not discuss the origin of the pulses themselves
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1969
- DOI:
- 10.1086/150160
- Bibcode:
- 1969ApJ...157.1395O