Birth Rates of Different Types of Neutron Stars and Possible Evolutions of These Objects

Abstract

We estimate the spatial densities of different types of neutron star near the Sun. It is shown that the distances of dim isolated thermal neutron stars must be on average about 300-400 pc. The combined birth rate of these sources together with radio pulsars and dim radio quiet neutron stars can be a little more than the supernova rate as some of the dim isolated thermal neutron stars can be formed from dim radio quiet neutron stars and radio pulsars. Some of these sources must have relations with anomalous X-ray pulsars and soft gamma repeaters. In order to understand the locations of different types of neutron star on the P-Ṗ diagram it is also necessary to take into

Possible Evolution of Dim Radio-Quiet Neutron Star 1e 1207.4-5209 Based on a B-Decay Model

“…Direct detection of neutron stars in many of the SNRs may not be possible because of the selection effects and the large distances. On the other hand, PWN is not seen around pulsars which have rate of rotational energy loss Ė<10 35 erg/s 5,16,17 . The only known DRQNS with measured P and Ṗ values is 1E 1207.4-5209 and it has Ė=2×10 34 erg/s.…”

“…As a last remark we would like to note that the birth rate of 1207-like X-ray pulsars must be about 20-30% of the total supernova rate (excluding type-Ia supernovae as this type of explosion most probably does not lead to formation of a neutron star) taking into consideration that the lifetime of such sources as X-ray pulsars must be about 2×10 4 yr because of rapid B-decay (see Guseinov et al 5 on the birth rates of different types of isolated neutron stars including dim radio quiet neutron stars some of which seem to be 1207-like objects based on the existing observational data).…”

“…All of them are physically connected to Galactic supernova remnants (SNRs) which have ages less than about 20 kyr 4,5 . There are two basic observable quantities of isolated pulsars: the rotation period P and the time rate of change of the rotation periodṖ.…”

“…There are only a few observationally known DRQNSs. All of them are physically connected to Galactic supernova remnants (SNRs) which have ages less than about 20 kyr 4,5 .…”

“…In such a case, the characteristic age (τ ) of pulsar is defined using the n=3 condition in eqn. (5):…”