EPoS Contribution
EPoS Contribution
Early stages of massive star cluster formation

Cinthya Herrera
NAOJ, Mitaka, Tokyo, JP
Based on near-IR H2 emission (VLT/SINFONI) and CO emission (ALMA), we identified a source we believe to be a progenitor of a massive super star cluster (pre-cluster cloud, PCC) in the overlap region of the Antennae galaxy merger. The characteristics of this source suggest that we are witnessing the formation of a cloud, massive enough to form a super star cluster, initiated by the dissipation of the gas turbulent kinetic energy. Turbulence at PCC scales is driven by the kinetic energy of the encounter, which is not thermalised in large scale shocks. The discovered source will fill the evolutionary stages between GMCs and massive star formation. In this talk, we will also present a second candidate for PCC in the Antennae and discuss our plans to pursue this work by observing with ALMA (Cycle 1 project) emission lines from molecules (SiO, CH3OH) identified in our Galaxy to form in shocks.
Caption: Color image in the background corresponds the Antennae galaxy merger as seen by the HST. Black contours represent the CO(3-2) integrated emission (ALMA SV Data). We zoom on the overlap region. In the left panel, the CO(3-2) integrated emission shows the molecular gas content. We inserted the spectrum of Super Giant Molecular Complex 2 (SGMC 2) where we identify two velocity components. In the right panel, the near-IR H2 integrated emission tracing the energy dissipation. In this map, we identify a compact H2 luminous source (PCC) in SGMC2, which as a counterpart in the CO gas. The bottom panel zooms on this molecular complex. The blue and red colors are the integrated CO emission for the two CO velocity components. White contours are the H2 integrated emission. The PCC source seems to be at the interface of blue and red shifted gas.
Collaborators:
F. Boulanger, IAS, France
N. Nesvadba, IAS, France
E. Falgarone, ENS-LERMA, France
Key publication

Suggested Sessions: Molecular Clouds