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

We use the Wide Field Camera 3 onboard the Hubble Space Telescope to obtaindeep, high-resolution photometry of the young (~ 100 Myr) star cluster NGC1850in the Large Magellanic Cloud. We analyze the cluster colour-magnitude diagram(CMD) and find that it hosts an extended main sequence turn-off (MSTO) and adouble MS. We demonstrate that these features cannot be due to photometricerrors, field star contamination, or differential reddening. From a comparisonwith theoretical models and Monte Carlo simulations, we show that a coevalstellar population featuring a distribution of stellar rotation rates canreproduce the MS split quite well. However, it cannot reproduce the observedMSTO region, which is significantly wider than the simulated ones. Exploitingnarrow-band Halpha imaging, we find that the MSTO hosts a population ofHalpha-emitting stars which are interpreted as rapidly rotating Be-type stars.We explore the possibility that the discrepancy between the observed MSTOmorphology and that of the simulated simple stellar population (SSP) is causedby the fraction of these objects that are highly reddened, but we rule out thishypothesis. We demonstrate that the global CMD morphology is well-reproduced bya combination of SSPs that cover an age range of ~ 35 Myr as well as a widevariety of rotation rates. We derive the cluster mass and escape velocity anduse dynamical evolution models to predict their evolution starting at an age of10 Myr. We discuss these results and their implications in the context of theextended MSTO phenomenon.

Dissecting the Extended Main Sequence Turn-off of the Young Star Cluster NGC1850