Spectacular new Milky Way map reveals colder parts of galaxy

Scientists are taking a new look at our galaxy.

To mark the completion of its latest survey, the European Space Observatory (ESO) has released a new image of the galaxy, visible above. It reveals concentrations of dense gas, captured by studying the sky in a new way – in the submillimeter band, using wavelengths of light that lie between radio waves and infrared radiation.

The survey, completed with one of ESO’s specialized telescopes in Chile, allowed astronomers to take a better look at some of the colder parts of the galaxy. The clouds of gas visible in the image have temperatures near absolute zero.

Why does the new survey matter? These dense, cold gas clouds are the future construction sites for new stars, and this map will help scientists find and study them.

This “provides exciting insights into where the next generation of high-mass stars and clusters form,” said Timea Csengeri from the Max Planck Institute for Radio Astronomy, in a press release. By combining the new information with observations from other telescopes and satellites, “we can now obtain a link to the large-scale structures of giant molecular clouds.”

To detect the almost absolute-zero regions of space, scientists used a sensitive camera to identify minuscule rises in temperature from dust bands blocking stellar light.

The data gained from those measurements, when partnered with previous observations from the European Space Agency's Planck space telescope, revealed the birthplaces of many new stars and the location of dense gas in a wide swath of the galaxy.

The new ATLASGAL map is about 140 degrees long and three degrees wide, which is about four times bigger than previous maps created by the Atacama Pathfinder EXperiment telescope (APEX) telescope.

It is “the single most successful” survey in the history of the APEX program, according to the press release.

Almost 70 scientific papers have been published based on the data gained from the survey and, as the data reaches the entire astronomical community, many more are expected.

The APEX telescope was originally based on the designs for an antenna for the large ALMA telescope and has long acted in a complementary capacity for the more powerful telescope. Now that the APEX has completed its initial mapping of the cold universe, the ALMA telescope could follow up with more detailed observations at some of the key locations APEX identified.

“ATLASGAL has allowed us to have a new and transformational look at the dense interstellar medium of our own galaxy, the Milky Way,” said ATLASGAL team member Leonardo Testi.