A benchmark for multiconjugated adaptive optics: VLT-MAD observations of the young massive cluster Trumpler14

• Published in: Monthly notices of the Royal Astronomical Society Vol. 418; no. 2; pp. 949 - 959
• Main Authors: Rochau, B, Brandner, W, Stolte, A, Henning, T, Da Rio, N, Gennaro, M, Hormuth, F, Marchetti, E, Amico, P
• Format: Journal Article
• Language: English
• Published: London Oxford University Press 01-12-2011
• Subjects: Optics; Stars & galaxies
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2011.19561.x

ABSTRACT The Multi-conjugate Adaptive optics Demonstrator (MAD) is the first multiconjugated adaptive optics system at the Very Large Telescope (VLT). We present H and KS observations of the young massive cluster Trumpler14 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 5.9per cent with maximum Strehl ratios of 9.8 and 12.6 per cent in H and KS, 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 10mag 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 ± 0.5Myr ago. We tentatively detect hints for an older population of 3Myr 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 mc 0.53+0.12- 0.10M. The MF appears shallow with power-law slopes of Γ1=-0.50 ± 0.11 above mc and Γ2= 0.63 ± 0.32 below mc.