2011MNRAS.418..949R

The Multi-conjugate Adaptive optics Demonstrator (MAD) is the first multiconjugated adaptive optics system at the Very Large Telescope (VLT). We present H and K_S observations of the young massive cluster Trumpler 14 revealing the power of MCAO systems by providing a homogeneous Strehl ratio over a large field of view. Mean Strehl ratios of 6.0 and 5.9 per cent with maximum Strehl ratios of 9.8 and 12.6 per cent in H and K_S, respectively, show significant improvement of the spatial point spread function (PSF) stability compared to single-conjugated adaptive optics systems. Photometry of our observations cover a dynamic range of ∼10 mag including 2–3 times greater number of sources than comparable seeing-limited observations. The colour–magnitude diagram reveals that the massive cluster originated in a recent starburst-like event 1±0.5 Myr ago. We tentatively detect hints for an older population of 3 Myr suggesting that low intensity star formation might have been going on in the HII region for a few Myr. We derive the luminosity function and mass function between 0.1 and 3.2 M_☉ and identify a change in the power-law slope of the mass function at m_c∼ 0.53^+0.12_- 0.10_M☉_. The MF appears shallow with power-law slopes of Γ₁=-0.50±0.11 above m_c and Γ₂= 0.63±0.32 below m_c.

Based on Observations with VLT–MAD collected during the Science Verification campaign at the European Southern Observatory, Paranal, Chile.