Supersonic Turbulence in the Perseus Molecular Cloud

Abstract

We compare the statistical properties of J=1-0 13CO spectra observed in the\nPerseus Molecular Cloud with synthetic J=1-0 13CO spectra, computed solving the\nnon-LTE radiative transfer problem for a model cloud obtained as solutions of\nthe three dimensional magneto-hydrodynamic (MHD) equations. The model cloud is\na randomly forced super-Alfvenic and highly super-sonic turbulent isothermal\nflow.\n The purpose of the present work is to test if idealized turbulent flows,\nwithout self-gravity, stellar radiation, stellar outflows, or any other effect\nof star formation, are inconsistent or not with statistical properties of star\nforming molecular clouds.\n We present several statistical results that demonstrate remarkable similarity\nbetween real data and the synthetic cloud. Statistical properties of molecular\nclouds like Perseus are appropriately described by random super-sonic and\nsuper-Alfvenic MHD flows. Although the description of gravity and stellar\nradiation are essential to understand the formation of single protostars and\nthe effects of star formation in the cloud dynamics, the overall description of\nthe cloud and of the initial conditions for star formation can apparently be\nprovided on intermediate scales without accounting for gravity, stellar\nradiation, and a detailed modeling of stellar outflows.\n We also show that the relation between equivalent line width and integrated\nantenna temperature indicates the presence of a relatively strong magnetic\nfield in the core B1, in agreement with Zeeman splitting measurements.\n