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P-Pdot diagram

(diagram comparing the rotation and the slowing of pulsars)

A P-Pdot diagram is a graph plotting the rates of change of pulsars' rotation periods (Pdot, meaning a dot "." over a P, for period derivative) against their rotation periods (P). The two values characterize a pulsar's rotation evolution, and such a diagram allows comparison and classification of pulsars in this respect, revealing the characteristics and evolution of pulsars in general. Pulsars' periods generally grow at a slow rate, but can occasionally jump to a slightly shorter period (a glitch), presumably due to a significant rearrangement of some of its mass, which could be thought of as a "pulsar quake" or perhaps the collapse of a hill on its surface. They also can reduce their rotation period by gaining angular momentum through accretion from a binary companion. Such diagrams show a clear distinction between pulsars that have a companion versus lone pulsars: those with a companion both have a shorter period and don't slow their rotation as quickly, placing them in a separate, distinct portion of the diagram.


(pulsars,astrophysics,rotation,period,diagram)
Further reading:
https://nanograv.org/glossary/p-pdot-diagram
https://radio.astro.gla.ac.uk/pulsar_course/lecture05.pdf
http://www.jb.man.ac.uk/distance/frontiers/pulsars/section1.html
https://en.wikibooks.org/wiki/Pulsars_and_neutron_stars/Pulsar_properties
https://ui.adsabs.harvard.edu/abs/2017MNRAS.467.3493J/abstract

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