| Abstract : | The Rotating Radio Transients (RRAT), characterised by their sporadic radio emissions, are one of the latest observational sub-classes of neutron stars. This group (consisting of ~162 objects detected so far) comprise a tiny subset of the ~3500 neutron stars known to date. Several conjectures have been put forward to explain the nature of their sporadic emission and their connections to other radio pulsars. In this work, we have considered the population of RRATs and discussed some of the prominent hypotheses (offered to explain the RRAT phenomenon) in view of their population characteristics. In particular, we have compared them with the population of nulling pulsars, as RRAT behaviour is commonly suspected to be an extreme form of nulling. We find that the statistical distributions of spin-period (Ps), surface magnetic field (Bs) and dispersion measure (DM) for the RRATs and the nulling pulsars are not correlated. While Ps and Bs tend to be higher for the RRATs, the average DM is smaller than that of the nulling pulsars,
indicating that the known RRATs, on average, consist of a nearby population of neutron stars compared to those of the nulling pulsars.
Moreover, our quantitative estimate for the death-line proximity for the RRATs indicates that their emission behaviour is not likely to be connected to old-age / nearness to the death-line. In conclusion, we find that the conjectures, invoking restructuring and/or evolution of the magnetic fields to explain the RRAT behaviour, are likely to hold maximum promise.
Reference :
[1] Abhishek, Malusare N., Tanushree N., Hegde G., Konar S., 2022,
arXiv:2201.00295,
submitted to `Journal of Astrophysics and Astronomy.' |
