English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Some of the most important information on a radio pulsar is derived from itsaverage pulse profile. Many early pulsar studies were necessarily based on onlyfew such profiles. There, discrete profile components were linked to emissionmechanism models for individual stars through human interpretation. For thepopulation as a whole, profiles morphology must reflect the geometry andoverall evolution of the radio emitting regions. The problem, however, is thatthis population is becoming too large for intensive studies of all sourcesindividually. Moreover, connecting profiles from a large collection of pulsarsrapidly becomes cumbersome. In this article, we present ToPP, the first-everunsupervised method to sort pulsars by profile-shape similarity, using graphtopology. We apply ToPP to the publicly available European Pulsar Networkprofile database, providing the first organised visual overview ofmulti-frequency profiles representing 90 individual pulsars. We find discreteevolutionary tracks, varying from simple, single component profiles at allfrequencies, towards diverse mixtures of more complex profiles with frequencyevolution. The profile evolution is continuous, extending out to millisecondpulsars, and does not fall in sharp classes. We interpret the profiles as amixture of pulsar core/cone emission type, spin-down energetics, and theline-of-sight impact angle towards the magnetic axis. We show how ToPP cansystematically classify sources into the Rankin empirical profile scheme. ToPPforms one of the key unsupervised methods that will be essential to exploreupcoming pulsar census data such as expected by the Square Kilometer Array.

Topology of Pulsar Profiles (ToPP). I. Graph theory method and classification of the EPN