Astronomers from Cardiff University, UK, have employed the Combined Array for Research in Millimeter-wave Astronomy (CARMA) to explore the nearby Andromeda galaxy. Results of the observational campaign, published December 27 on the pre-print server arXiv, yield important insights into the molecular cloud system of this galaxy.

Molecular clouds are huge complexes of interstellar gas and dust left over from the formation of galaxies, composed mostly of molecular hydrogen. Such clouds with masses greater than 100,000 solar masses are called giant molecular clouds (GMCs). In general, GMCs are 15–600 light years in diameter and are the coldest and densest parts of the interstellar medium.

The Andromeda galaxy, also known as Messier 31, is the nearest major galaxy to the Milky Way. It is a barred spiral galaxy with a diameter of about 152,000 light years and a mass of some 1.5 trillion solar masses.