Angles between the Magnetic Moment and the Rotation Axis in Radio Pulsars with Hard Emission

Abstract

We have performed a comparative analysis of the angles β between the rotation axis and themagnetic moment in three groups of radio pulsars: sources inwhich only radio emission is observed, pulsarswith detected X-ray emission, and radio-loud gamma-ray pulsars. For this purpose, we have calculated thevalues of the angle β separately for objects from each group by two differentmethods. It has turned out thatin pulsars with hard emission themean values of this angle (28.2◦ and 28.8◦) are greater than those for quietradio pulsars (12.9◦). However, using the Kolmogorov–Smirnov test, we have shown that the revealeddifference is insignificant with a high probability. Consequently, the structures of the magnetospheres in thethree groups of pulsars considered do not differ greatly, while their difference is attributable to the magneticfield strength on the light cylinder that switches on the hard nonthermal emission mechanism in pulsarswith detected X-ray and/or gamma-ray emission but is not enough for this in quiet radio pulsars in thehard ranges.