Space

Release of new galactic map marks completion of ATLASGAL survey

Written By: Chuck Bednar
Brian Galloway

A groundbreaking effort to study the cold universe, a collection of dust and gas a handful of degrees above absolute zero, has come to an end following the release of a new image of the Milky Way covering a 140-degree long, 3 degree-wide area of the sky.

The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) survey, which began collecting data nearly 10 years ago, was designed to map the entire area of the Galactic Plane visible from the southern hemisphere in submillimeter wavelengths for the first time.

This video gives you a sense of scale for the sheer size of this project:

In addition, it used the 12-meter APEX (Atacama Pathfinder Experiment) telescope, which is located 5,100 meters above sea level on the Chajnantor Plateau in Chile, to create maps of the sky in greater detail than was possible with previous space-based surveys, astronomers at the European Southern Observatory (ESO) explained Wednesday in a statement.

Thanks to the unique properties of the APEX telescope, the ATLASGAL survey was able to provide and in-depth look at how cold, dense gas is distributed along the plane of our galaxy, including areas of star formation located in the southern Milky Way, the ESO added.

This image of the Milky Way has been released to mark the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The APEX telescope in Chile has mapped the full area of the Galactic Plane visible from the southern hemisphere for the first time at submillimetre wavelengths — between infrared light and radio waves — and in finer detail than recent space-based surveys. The APEX data, at a wavelength of 0.87 millimetres, shows up in red and the background blue image was imaged at shorter infrared wavelengths by the NASA Spitzer Space Telescope as part of the GLIMPSE survey. The fainter extended red structures come from complementary observations made by ESA's Planck satellite. Many of the most prominent objects are named and the parts of the galaxy that are shown in the three slices are indicated at the right.

Credit: ESO

Survey’s completion ‘opens up the possibility’ of new discoveries

The newly released images map an area of the sky four times larger than the first ones created using the APEX telescope nearly 10 years ago, and are said to also be of higher quality, as the team took a second look at some previously observed areas to obtain more uniform results across the entire survey area.

The ATLASGAL survey, which has to date already resulted in the publication of more than 65 scientific papers, used the APEX telescope’s Large Bolometer Camera (LABOCA) to measure incoming radiation by detecting slight increases in temperature, the ESO said. In addition, it can detect emissions from the cold, dark dust bands that obscure light from the sun.

The release of the new image brings the ATLASGAL survey to an end. Over the past decade, its data has helped detect emission spread over a large area of the sky, estimate the amount of dense gas located in the inner galaxy, and create a census of cold and massive gas clouds in parts of the galaxy where new stars are forming.

“ATLASGAL provides exciting insights into where the next generation of high-mass stars and clusters form,” said ATLASGAL scientist Timea Csengeri of the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany. “By combining these with observations from Planck, we can now obtain a link to the large-scale structures of giant molecular clouds.”

“ATLASGAL has allowed us to have a new and transformational look at the dense interstellar medium of our own galaxy, the Milky Way,” the ESO’s Leonardo Testi added. “The new release of the full survey opens up the possibility to mine this marvelous dataset for new discoveries. Many teams of scientists are already using the ATLASGAL data to plan for detailed ALMA follow-up.”

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Image credit: ESO