Galactic clouds swathed in fog

摘要

Molecular clouds, where stars are born, are surrounded by a fog of hydrogen that interacts with the clouds. These interactions could affect whether stars form. In the Plateau de Bure Interferometer Arcsecond Whirlpool Survey, astronomers led by Eva Schinnerer of the Max Planck Institute for Astronomy in Heidelberg, Germany, mapped 1,500 giant molecular clouds in the Whirlpool galaxy, about 7 million parsecs (23 million light years) away. They report in a series of papers that the clouds are not isolated as previously thought, but are embedded in a molecular fog that is much denser than expected and contains 50% of the galaxy's hydrogen.