The relationship between accretion and ionized ejection among young stellar objects in the Coronet cluster

ABSTRACT We present results from a coordinated, multi-epoch near-infrared and centimetre radio survey of young stellar objects (YSOs) in the Coronet, aimed at probing the connection between mass accretion and ionised mass-loss. Using VLT-KMOS, we detect Br$\gamma$ emission in 5 of the 26 targets, which also exhibit 3.3-cm continuum emission in VLA images, consistent with partially ionised jets. For seven additional sources, stringent flux upper limits were obtained. The derived accretion and ionized mass-loss rates for class i and class ii YSOs follow a sublinear correlation $\dot{M}_{\mathrm{ion}} \propto \dot{M}_{\mathrm{acc}}^{0.3}$, consistent with previous results for class ii YSOs but extended here to earlier stages. Multi-epoch observations reveal modest variability in both tracers but no clear temporal correlation between accretion and ejection within time-scales of a few months. The ratio $\dot{M}_{\mathrm{ion}}/\dot{M}_{\mathrm{acc}}$ shows an anticorrelation with $\dot{M}_{\mathrm{acc}}$, increasing with time from class i YSOs to class ii YSOs, suggesting an increase in jet-launching efficiency or ionization fraction with evolution. These findings support a direct connection between accretion and outflow across the $\sim$ Myr time-scale of YSO evolution, while highlighting the complexity of their short-term interplay.