Quang Nguyen Luong


W43: GMC formed by converging flows at the tip of the Galactic Bar

F. Motte, F. Schuller, N. Schneider, S. Bontemps, P. Schilke, K. Menten, F. Heitsch, F. Wyrowski, P. Carlhoff


Using continuum data at infrared and submm wavelengths in combination with multiple CO isotopologues, we have identified W43 as one of the most extreme molecular cloud complex of the Milky Way. We also derived its distance to be at ~6 kpc from the Sun. The cloud component of W43 is found to be massive (~7106 Mwithin a 140 pc equivalent diameter), highly concentrated (~8105 Mwithin a < 5 pc star-forming sites) and very dynamic (ΔV ~ 20 km s−1). We suggest that the star-formation activity of W43 is very high, up to levels typical of starburst (star formation rate ~0.1 Myr−1). We also interpreted it as locating at the near-tip of the Galactic long in-plane Bar. This location is the meeting point of the Scutum-Centaurus arm and the Galactic Bar, a dynamically complex region where high-velocity streams could easily collide. Numerical simulations suggest that this location can contribute to explain the exceptional characteristics of W43 through the converging of different flows. In this talk, I will show the results from different continuum wavelengths (Hi-GAL and ATLASGAL) and the molecular lines data from the IRAM 30m large mapping survey to emphasize the special global characteristics of W43 and the observational manifestations of W43 which support the theory of converging flows and the existence of a Galactic long bar.