Supersonic Turbulence in the Perseus Molecular Cloud
P. Padoan, J. Bally, Y. Billawala, M. Juvela, Å Nordlund, ke;
ApJ, 1999, 525, 318
ABSTRACT:We compare the statistical properties of J=1-->0 13CO spectra observed in the Perseus molecular cloud with synthetic J=1-->0
13CO spectra, computed solving the non-LTE radiative transfer problem for
a model cloud obtained as solutions of the three-dimensional
magnetohydrodynamic (MHD) equations.
The model cloud is a randomly forced
super-Alfvénic and highly supersonic turbulent isothermal flow.
The purpose of the
present work is to test if idealized turbulent flows, without self-gravity,
stellar radiation, stellar outflows, or any other effect of star formation,
are inconsistent or not with statistical properties of star-forming
molecular clouds.
We present several statistical results that demonstrate
remarkable similarity between real data and the synthetic cloud.
Statistical
properties of molecular clouds like Perseus are appropriately described by
random supersonic and super-Alfvénic MHD flows.
Although the
description of gravity and stellar radiation are essential to understand the
formation of single protostars and the effects of star formation in the cloud
dynamics, the overall description of the cloud and of the initial conditions for
star formation can apparently be provided on intermediate scales without
accounting for gravity, stellar radiation, and a detailed modeling of stellar
outflows.
We also show that the relation between equivalent line width and
integrated antenna temperature indicates the presence of a relatively strong
magnetic field in the core B1, in agreement with Zeeman splitting
measurements.
KEYWORDS: ism: individual (perseus), ism: kinematics and dynamics, ism: magnetic fields, magnetohydrodynamics: mhd, turbulence
PERSOKEY:turbulence, ,
CODE: padoan99