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

Extended MS turn-offs are features commonly found in the colour-magnitudediagrams of young and intermediate age (less than about 2 Gyr) massive starclusters, where the MS turn-off is broader than can be explained by photometricuncertainties, crowding, or binarity. Rotation is suspected to be the cause ofthis feature, by accumulating fast rotating stars, strongly affected by gravitydarkening and rotation-induced mixing, near the MS turn-off. This scenariosuccessfully reproduces the tight relation between the age and the actualextent in luminosity of the extended MS turn-off of observed clusters. Below agiven mass (dependent on the metallicity), stars are efficiently braked earlyon the MS due to the interaction of stellar winds and the surface magneticfield, making their tracks converge towards those of non-rotating tracks in theHRD. When these stars are located at the turn-off of a cluster, their slowrotation causes the extended MS turn-off feature to disappear. We investigatethe maximal mass for which this braking occurs at different metallicities, anddetermine the age above which no extended MS turn-off is expected in clusters.Our models predict that the extended MS turn-off phenomenon disappears at agesolder than about 2 Gyr. There is a trend with the metallicity, the age at whichthe disappearance occurs becoming older at higher metallicity. These resultsare robust between the two codes used in this work, despite some differences inthe input physics and in particular in the detailed description ofrotation-induced internal processes and of angular momentum extraction bystellar winds. Comparing our results with clusters in the LMC and Galaxy showsa very good fit to the observations. This strengthens the rotation scenario toexplain the cause of the extended MS turn-off phenomenon.

Disappearance of the extended main sequence turn-off in intermediate age clusters as a consequence of magnetic braking