Nearby Galaxies
Studies of the interstellar medium provide key information about the physical and chemical processes which drive the evolution of galaxies. Observations in the sub-millimeter wavelength regime, as provided by APEX, Herschel ALMA and NOEMA, are in particular critical as they trace the cold gas reservoir - the material from which new generations of stars are born. The relations between the chemical and physical properties of the cold molecular gas and star formation are key research areas of our group. In the coldest phase, the interstellar medium is mainly molecular. Observations of molecular emission lines and radiation from dust grains allow us to measure the gas kinematics, cooling balance and chemical composition of the molecular clouds. The environment in which cold clouds reside largely affects their capabilities to form stars. Observations of nearby galaxies probe the full scale of conditions met in the local universe and therefore provide important clues to interpret the star formation and galaxy evolution in the early universe.
The Apex Magellanic Cloud Legacy Survey
In the local universe star formation is exclusively associated with molecular clouds. Understanding the efficiency of this process, the environmental conditions under which star formation occurs and the impact of feedback from newly formed massive stars on this process is a crucial goal of modern astrophysics.
Numerical simulations and theory have consistently shown that the interstellar medium should be highly filamentary and that star formation is intimately related to self-gravitating filaments. These structures can be identified in large scale surveys in the MW, but in nearby galaxies the spatial resolution of molecular cloud studies is typically too poor to allow resolving the relevant spatial scales even with ALMA.
With their proximity of only 50 kpc, our nearest neighbours - the Large and Small Magellanic Clouds - offer a unique laboratory to study the star formation process in cold, dense molecular clumps and filaments. Even with the APEX telescope we are able to study the gas at a high spatial resolution of 4 pc.
The MPIfR with its international partners is currently conducting the Apex Magellanic Cloud Legacy Survey to map the distribution of the dense molecular gas in the CO(3-2) and 13CO(3-2) emission lines using the 345-GHz LASMA 7-pixel array receiver at APEX. The survey has a total areal coverage of 15deg2 and will cover all main dust complexes in the Large and Small Magellanic Clouds down to a molecular mass completeness limit of 300 Msol.