Hidden star nurseries discovered in the Milky Way

A new research has revealed an unprecedented number of cold dense clumps of gas and dust as the cradles of massive stars, thus providing a complete view of their birthplaces in the Milky Way.

An international team of astronomers used the APEX telescope with its submillimeter camera, LABOCA, built at the Max Planck Institute for Radio Astronomy (MPIfR), to survey the inner galaxy to search for the birthplaces of the most massive stars currently forming in the Milky Way.

The APEX telescope is located on the Chajnantor Plateau in Chile at 5,100 m altitude, which is one of the few places on Earth where observations at submillimeter wavelengths are possible.

The ATLASGAL survey covers more than 420 square degrees of the galactic plane, which corresponds to 97 per cent of the inner galaxy within the solar circle. Thus it includes large sections of all four spiral arms, and approximately two thirds of the entire molecular disc of the Milky Way.

This data set therefore includes the majority of all massive star forming nurseries in the galaxy and is being used to construct a 3D map of the Milky Way.

The APEX Telescope Large Area Survey of the galaxy (ATLASGAL) provides an unprecedented census of the cold and dense environments where the most massive stars in our galaxy begin their lives. The material in these stellar nurseries is so dense that optical and infrared light emitted from the embedded young high-mass stars cannot escape.

Therefore, the earliest stages of star formation are effectively hidden at these short wavelengths and longer wavelengths are required to probe these regions. The ATLASGAL survey detects emission at submillimeter wavelengths, which is dominated by emission from cold dust. It provides a detailed view of the birthplaces where the next generation of massive stars is being formed.