Adapted from a press release of the Royal Astronomical Society (RAS):
A team of international astronomers has created a detailed three-dimensional map of the dusty structure of the Milky Way, as seen from Earth’s northern hemisphere.
Dust and gas, which make up the interstellar medium (ISM), fill the space between stars in galaxies. The dust in the ISM is shaped by turbulent flows that form intricate fractal structures on scales ranging from thousands of light years down to hundreds of kilometers. Rather than measuring the dust itself to create the map, the team has used observations of more than 38 million stars to estimate how much starlight has been obscured by the ISM and thus how much dust lies in our line of sight to each star. This ‘extinction’ map derives from the newly released catalog of the Isaac Newton Telescope Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS), the first digital survey to cover the entire northern Milky Way.
The map shows how extinction builds with distance away from the Sun (typically out to 12,000 light years or more) in any part of the surveyed northern Milky Way. The fractal nature of the ISM is visible in the map, as are large-scale features, such as star-forming molecular clouds and bubbles of ionized gas around clusters of hot stars.