The Thousand-Pulsar-Array programme on MeerKAT XV: A comparison of the radio emission properties of slow and millisecond pulsars

TL;DR

This study compares radio emission properties of millisecond and slow pulsars using MeerKAT data, finding similar spectral, profile, and polarization characteristics, suggesting common emission physics despite different magnetic field strengths.

Contribution

It demonstrates that after appropriate scaling, MSPs and slow pulsars have similar intrinsic radio luminosities, challenging previous assumptions about their emission differences.

Findings

Similar spectral steepness for both pulsar types

Profile width dependence on rotation period is consistent

Scaled pseudo-luminosity shows no clear difference in intrinsic luminosity

Abstract

We use data from the MeerTime project on the MeerKAT telescope to ask whether the radio emission properties of millisecond pulsars (MSPs) and slowly rotating, younger pulsars (SPs) are similar or different. We show that the flux density spectra of both populations are similarly steep, and the widths of MSP pulsar profiles obey the same dependence on the rotational period as slow pulsars. We also show that the polarization of MSPs has similar properties to slow pulsars. The commonly used pseudo-luminosity of pulsars, defined as the product of the flux density and the distance squared, is not appropriate for drawing conclusions about the relative intrinsic radio luminosity of SPs and MSPs. We show that it is possible to scale the pseudo-luminosity to account for the pulse duty cycle and the solid angle of the radio beam, in such a way that MSPs and SPs do not show clear differences in intrinsic luminosity. The data, therefore, support common emission physics between the two populations in spite of orders of magnitude difference in their period derivatives and inferred, surface, dipole magnetic field strengths.