Results of SPARO 2003: Mapping Magnetic Fields in Giant Molecular Clouds

First Results from Sparo: Evidence for Large-scale Toroidal Magnetic Fields in the Galactic Center

We have observed the linear polarization of 450 μm continuum emission from the Galactic center, using a new polarimetric detector system that is operated on a 2 m telescope at the South Pole. The resulting polarization map extends ∼ 170 pc along the Galactic plane and ∼ 30 pc in Galactic latitude, and thus covers a significant fraction of the central molecular zone. Our map shows that this regi...

Magnetic Fields in Diffuse H I and Molecular Clouds

Giant Molecular Clouds in M 64

We investigate the properties of Giant Molecular Clouds (GMCs) in the molecule-rich galaxy M64 (NGC 4826). In M64, the mean surface density of molecular gas is 2N (H 2) ∼ 10 22 over a 2 kpc region, equal to the surface densities of individual GMCs in the Milky Way. We observed the J = 1 → 0 transitions of CO, 13 CO, and HCN. The line ratio W CO /W 13CO for 200 pc < R gal < 800 pc is comparable ...

Giant Molecular Clouds in Local Group Galaxies

We present the first comparative study of extragalactic GMCs using complete data sets for entire galaxies and a uniform set of reduction and analysis techniques. We present results based on CO observations for the LMC, SMC, M33, M31, IC10 and the nucleus of M64, and make comparisons with archival Milky Way observations. Our sample includes large spirals and dwarf irregulars with metallicities t...

TURBULENCE AND MAGNETIC FIELDS IN CLOUDS Discussion

We discuss several categories of models which may explain the IMF, including the possible role of turbulence and magnetic fields.