The Initial Mass Function of the Massive Star-forming Region NGC 3603 from Near-Infrared Adaptive Optics observations

Understand

We study the initial mass function (IMF) of one of the most massive Galactic star-forming regions NGC 3603 to answer a fundamental question in current astrophysics: is the IMF universal, or does it vary? Using our very deep, high angular resolution JHKsL' images obtained with NAOS-CONICA at the VLT at ESO, we have successfully revealed the stellar population down to the subsolar mass range in the core of the starburst cluster.

• The derived IMF of NGC 3603 is reasonably fitted by a single power law with index Gamma ~ -0.74 within a mass range of 0.4 - 20 Msun, substantially flatter than the Salpeter-like IMF.
• A strong radial steepening of the IMF is observed mainly in the inner r < 30'' field, indicating mass segregation in the cluster center.
• We estimate the total mass of NGC 3603 to be about 1.0 - 1.6 x 10^4 Msun.