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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Based on Insight-HXMT data, we report on the pulse fraction evolution duringthe 2017-2018 outburst of the newly discovered first Galactic ultraluminousX-ray source (ULX) Swift J0243.6+6124. The pulse fractions of 19 observationpairs selected in the rising and fading phases with similar luminosity areinvestigated. The results show a general trend of the pulse fraction increasingwith luminosity and energy at super-critical luminosity. However, the relativestrength of the pulsation between each pair evolves strongly with luminosity.The pulse fraction in the rising phase is larger at luminosity below$7.71\times10^{38}$~erg~s$^{-1}$, but smaller at above. A transition luminosityis found to be energy independent. Such a phenomena is firstly confirmed byInsight-HXMT observations and we speculate it may have relation with theradiation pressure dominated accretion disk.

Insight-HXMT observations of Swift J0243.6+6124: the evolution of RMS pulse fractions at super-Eddington luminosity