Filaments and ridges in Vela C revealed by Herschel: from low-mass to high-mass star-forming sites
Bernard, J. -P.; Martin, P. G.; Hill, T.; White, G. J.; Roussel, H.; André, Ph.; Arzoumanian, D.; Könyves, V.; Testi, L.; Sauvage, M.; Marston, A. P.; Wilson, C. D.; Schneider, N.; Bontemps, S.; Zavagno, A.; Men'shchikov, A.; Didelon, P.; Peretto, N.; Elia, D.; Griffin, M. J.; Kirk, J.; Motte, F.; Pezzuto, S.; Ward-Thompson, D.; Hennemann, M.; Nguyen Luong, Q.; Minier, V.; Molinari, S.; Giannini, T.; di Francesco, J.; Anderson, L. D.; Sousbie, T.
France, Canada, Italy, United Kingdom, Spain, Germany
Abstract
We present the first Herschel PACS and SPIRE results of the Vela C molecular complex in the far-infrared and submillimetre regimes at 70, 160, 250, 350, and 500 μm, spanning the peak of emission of cold prestellar or protostellar cores. Column density and multi-resolution analysis (MRA) differentiates the Vela C complex into five distinct sub-regions. Each sub-region displays differences in their column density and temperature probability distribution functions (PDFs), in particular, the PDFs of the "Centre-Ridge" and "South-Nest" sub-regions appear in stark contrast to each other. The Centre-Ridge displays a bimodal temperature PDF representative of hot gas surrounding the HII region RCW 36 and the cold neighbouring filaments, whilst the South-Nest is dominated by cold filamentary structure. The column density PDF of the Centre-Ridge is flatter than the South-Nest, with a high column density tail, consistent with formation through large-scale flows, and regulation by self-gravity. At small to intermediate scales MRA indicates the Centre-Ridge to be twice as concentrated as the South-Nest, whilst on larger scales, a greater portion of the gas in the South-Nest is dominated by turbulence than in the Centre-Ridge. In Vela C, high-mass stars appear to be preferentially forming in ridges, i.e., dominant high column density filaments.
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix A is available in electronic form at http://www.aanda.org