8-12 juin, 2014


The youngest massive star clusters near the centers of galaxies

Sherry Yeh (Subaru Telescope)

Chao-Wei Tsai (Caltech/JPL) Tom Geballe (Gemini North)

We present a straightforward approach to study the youngest (<3Myr) and highly obscured clusters in ground-based MIR observations. The Kennicutt-Schmitt Law does not necessarily operate near the centers of galaxies (CoGs), and the universality of the cluster formation efficiency (CFE) is yet to be validated. Ground-based [NeII] imaging is free from extinction, and it simultaneously delivers high angular resolution and recovers extended emission, critical for surveying CFEs consistently. We mapped the nucleus of NGC 6946 in [NeII] using Subaru Telescope. By comparing the [NeII] emission of young massive clusters (YMCs) 10^4 to 10^5 Msun and extended features, we estimated the CFE to be ∼13%, similar to that found in other environments. We will observe YMCs in 4 more galaxies, and spectroscopic followups will constrain the ages and densities of YMCs and HII regions, revealing how stellar feedback couples with the environment, and whether YMCs form in situ or via migration near CoGs.
(doit être confirmé par le SOC)