Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 1K104

THE ARCHES CLUSTER OUT TO ITS TIDAL RADIUS: DYNAMICAL MASS SEGREGATION AND THE EFFECT OF THE EXTINCTION LAW ON THE STEL- LAR MASS FUNCTION

Habibi, Maryam (University of Bonn)
Stolte, Andrea (University of Bonn)
Brandner, Wolfgang (Max-Planck-Institut für Astronomie, Heidelberg)
Hussman, Benjamin (University of Bonn)

Abstract:
The Galactic Center is the most active site of star formation in the Milky Way Galaxy, where particularly high-mass stars have formed very recently and are still forming today. However, since we are looking at the Galactic Center through the Galactic disk, knowledge of extinction is crucial to study this region. The Arches cluster is a young, massive starburst cluster near the Galactic Center. We observed the Arches cluster out to its tidal radius using Ks-band imaging obtained with NAOS/CONICA at the VLT combined with Subaro/Cisco J-band data to gain a full understanding of the cluster mass distribution. We show that the determination of the mass of the most massive star in the Arches cluster, which had been used in previous studies to establish an upper-mass limit for the star formation process in the Milky Way, strongly depends on the assumed slope of the extinction law. Assuming the two regimes of widely used infrared extinction laws, we show that the difference can reach up to 30% for individually derived stellar masses and ∆AKs∼1 magnitude in acquired Ks-band extinction, while the present mass function slope changes by ∼0.17 dex. The present-day mass function slope derived assuming the Nishiyama et al. (2009) extinction law increases from a flat slope of α-Nishi = 1.50 ± 0.35 in the core (r<0.2 pc) to α-Nishi = 2.21±0.27 in the intermediate annulus (0.2
Click here to view poster PDF