Munich, March 8 : Astronomers have measured the distribution of mass inside a dark filament in a molecular cloud with an amazing level of detail and to great depth, which would allow them to better understand the cradles of newborn stars.
The measurement, which is based on a new method that looks at the scattered near-infrared light or 'cloudshine', was made using the ESO's (European Southern Observatory) New Technology Telescope.
The vast expanses between stars are permeated with giant complexes of cold gas and dust opaque to visible light. Yet these are the future nurseries of stars to be.
"One would like to have a detailed knowledge of the interiors of these dark clouds to better understand where and when new stars will appear," said Mika Juvela, lead author of the paper in which these results are reported.
In 2006, astronomers Padoan, Juvela, and colleague Veli-Matti Pelkonen, proposed that maps of scattered light could be used as another tracer of the cloud's inner structure, a method that should yield more advantages. The idea is to estimate the amount of dust located along the line of sight by measuring the intensity of the scattered light.
The maps of scattered light can be used to measure the mass of the material inside the cloud.
To put this method to the test and use it for the first time for a quantitative estimation of the distribution of mass within a cloud, the astronomers who made the original suggestion, together with Kalevi Mattila, made observations in the near-infrared of a filament in the Corona Australis cloud.
Their observations confirm that the scattering method is providing results that are as reliable as the use of background stars while providing much more detail.
"We can now obtain very high resolution images of dark clouds and so better study their internal structure and dynamics," said Juvela.
"Not only is the level of details in the resulting map no longer dependent on the distribution of background stars, but we have also shown that where the density of the cloud becomes too high to be able to see any background stars, the new method can still be applied," he added.
"The presented method and the confirmation of its feasibility will enable a wide range of studies into the interstellar medium and star formation within the Milky Way and even other galaxies," said Mattila.
"This is an important result because, with current and planned near- infrared instruments, large cloud areas can be mapped with high resolution," said Pelkonen. "Using our method, it will prove amazingly powerful for the study of stellar nurseries," he added.