If you examine the night sky, you will soon notice that there is a lot of dust and gas. Interstellar dust between stars accounts for 1% of the mass of the interstellar medium, but reflects 30% of starlight in the infrared wavelength range. Dust plays an important role in star formation and galaxy evolution. A team of astronomers attempted to map dust 3,000 light-years away and published the first 3D map of dust in our galaxy.

The scattering and absorption (attenuation) of starlight by dust particles allows us to study dust clouds in three dimensions. It also tends to absorb shorter wavelengths than stars, causing stars obscured by clouds to appear redder. By analyzing this, the degree of dust disappearance along the line of sight can be estimated. If you take into account distance measurements to stars, you can create a three-dimensional map of dust clouds.

Gaia is a game-changer in understanding the distribution and collection of data for model building. Gaia is the European Space Agency’s astrometric observatory that maps the distances and positions of stars in the galaxy.

Since its launch 10 years ago, it has collected data from 1 billion stars, most of which are a few kiloparsecs away from the Sun (1 parsec equals 3.26 light years). Accurate knowledge of the position of stars allows reducing errors in dust removal simulations. It is time to investigate the three-dimensional distribution of dust in the Milky Way with a combination of stellar astrometry, photometry, extinction data and spectroscopy.

The study, led by lead author Gordian Edenhofer from the Max Planck Institute for Astrophysics, has been accepted for publication. Astronomy and Astrophysics. Currently available on the preprint server arXiv. The team presents a 3D dust map that goes deeper into space with a higher resolution than ever before. The processing technology allowed the team to examine dust distribution over 1 kiloparsec and recognize nearby dust clouds with parsec accuracy.

They were able to map dust 1.25 kiloparsecs away at higher resolution than before. This was because they used distance and extinction estimates from previous studies, which have less uncertainty than other datasets. Its maps have an angular resolution of up to 14 arcminutes and distance resolution on the parsec scale. It is always nice to find a result that is consistent with previous studies and existing 3D dust maps. But when it goes further, it gets even better, improving the area covered and with a higher spatial resolution than before.

As is often the case—and this is one of the reasons I love science—the map is publicly available on the internet, and anyone interested can query and view it using a Python package. The team hopes the maps will be used to further investigate the distribution of dust and the nature of the interstellar medium.