2008/02/09 by Enrique Vazquez‐Semadeni, Javier Ballesteros‐Paredes, Vazquez-Semadeni, Enrique +5
Chemistry · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Spectroscopy and Laser Applications #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.0802.1291
openalex publication_date 2008/02/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present preliminary numerical evidence that the physical conditions in high-mass star forming regions can arise from global gravitational infall, with the velocity dispersions being caused primarily by infall motions rather than random turbulence. To this end, we study the clumps and cores appearing in the region of central collapse in a numerical simulation of the formation, evolution, and subsequent collapse of a dense cloud out of a transonic compression in the diffuse atomic ISM. The clumps have sizes ∼ 1 pc, masses of several hundred M_\odot, and three-dimensional velocity dispersions ∼ 3 km s-1, in agreement with typical observed values for such structures. The clumps break down into massive cores of sizes ∼ 0.1 pc, densities ∼ 105, masses 2-300 M_\odot, with distributions of these quantities that peak at the same values as the massive core sample in a recent survey of the Cygnus X molecular cloud complex. Although preliminary, these results suggest that high-mass star forming clumps may be in a state of global gravitational collapse rather than in equilibrium supported by strong turbulence.