Mass Functions and Mass Segregation in Young Starburst Clusters

The Milky Way starburst clusters Arches in the Galactic Center region and NGC 3603 in the Carina spiral arm are studied with the aim to gain deeper insight into the stellar mass distribution in starburst clusters. The dense stellar population in both clusters is resolved in unprecedented detail with high angular resolution, near-infrared instruments. In the case of the Arches cluster, diffraction-limited, adaptive optics observations are analysed, and the achievements and limitations of ground-based vs. space-based diffraction-limited imaging are revealed by comparison with HST/NICMOS data. In the case of NGC 3603, seeing-limited JHKL photometry is used to derive colour-excess fractions, and is complemented by space-based Halpha data, both serving as tracers for circumstellar disks. Disk survival in starburst clusters is discussed. The present-day mass function (MF) of both clusters is deduced from colour-magnitude diagrams. Radial variations in the MFs reveal a heavily mass-segregated core in both starburst clusters. Dynamical timescales are estimated and interpreted with respect to primordial and dynamical segregation. The implications for massive star and cluster formation scenarios are discussed. Evidence for a low-mass cut-off is observed in the Arches MF, but not in NGC 3603, indicating a reduced formation efficiency for M < 10 Msun stars in the Galactic Center. This environmental difference has strong implications for the formation of stellar populations in galactic nuclei and starburst galaxies.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Heidelberg

Year

2003

Author dc:creator

• Stolte, Andrea

Contributors dc:contributor

• Rix, Hans-Walter

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/3611

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:3611