On the pulse-width statistics in radio pulsars. II. Importance of the core profile components

TL;DR

This study statistically analyzes core component pulse-widths in radio pulsars, confirming a lower bound relation with pulsar period and validating a method to estimate inclination angles, with implications for pulsar geometry understanding.

Contribution

It provides a larger database confirming the pulse-width period relation and validates a geometrical estimation method for pulsar inclination angles.

Findings

Confirmed the lower bound relation W50~2.45deg P^(-0.5).

Validated Rankin's inclination angle estimation method.

Found all single-pole interpulse pulsars above the boundary line.

Abstract

We performed a statistical analysis of half-power pulse-widths of the core components in average pulsar profiles. We confirmed an existence of the lower bound of the distribution of half-power pulse-width versus the pulsar period W50~2.45deg P^(-0.5) found by Rankin (1990). Using our much larger database we found W50= (2.51 +/- 0.08)deg P^(-0.50 +/-0.02) for 21 pulsars with double-pole interpulses for which measurement of the core component width was possible. On the other hand, all single-pole interpulse cases lie in the swarm of pulsars above the boundary line. Using the Monte Carlo simulations based on exact geometrical calculations we found that the Rankin's method of estimation of the inclination angle alpha ~ asin(2.45deg P^(-0.5)/W50) in pulsars with core components is quite good an approximation, except for very small angles alpha in almost aligned rotators.