Astronomers get a 3D glimpse of nearby stellar nurseries
Make a 3D map
Scientists have been studying 2D projections of Taurus and Perseus in the sky for a century. But how do they make the jump to 3D?
Dust makes up only a small percentage of the mass of a star-forming cloud. However, it turns out to be an excellent tracer of the dominant molecular gas from which stars are born. That’s why, in the new study, astronomers looked at the star-forming regions of Taurus and Perseus on 3D dust maps. published in 2020 by co-author Reimar Leike and collaborators from the Max Planck Institute for Astrophysics in Germany. The maps extend up to a distance of 1,300 light years from the Sun and show detail up to features just over 3 light years away.
To create such a map, Leike’s team collected information on about 5 million stars in the solar neighborhood. They used the colors of the stars, which can be affected by the dust between the Earth and the stars, to determine how much dust is in different directions. They then combined this information with precise distances to the stars, provided by the European Space Agency’s groundbreaking Gaia spacecraft.
“Before the launch of the Gaia Space Observatory, we generally knew where the regions of star formation are in a galaxy with 20-30% accuracy, which is a huge [margin of error], “said Catherine zucker, post-doctoral fellow at the Center d’Astrophysique | Harvard & Smithsonian in Cambridge, Massachusetts, and co-author of the new study. “With Gaia, our distance accuracy has increased fivefold. “
Now Zucker and his collaborators finally got to look at the true shapes of the clouds – and they were surprised.
Supernovae and star births
In 2D projections, Taurus and Perseus appear connected by a bridge of smooth material. However, the 3D map revealed that they were in fact physically separate clouds. Additionally, the two appear to be part of an almost spherical shell with a radius of around 245 light years.
Additionally, the team’s inspection of various images of the region taken at different wavelengths revealed that the clouds represent the aftermath of several supernovae that exploded in the central part of the shell over the past 6 years. in the last 22 million years. The explosions spread outward, compressing the gas and dust and creating the conditions for new stars to form.
Indeed, astronomers know that supernova explosions are one of the main regulators of star formation in the Milky Way. “They trigger star formation locally at specific locations, while globally they help suppress star formation,” explains Munan gong, postdoctoral researcher at the Max Planck Institute for Extraterrestrial Physics in Germany, who was not involved in the study. The Perseus-Taurus complex now offers the first 3D observational view of the results of this complex process.
Gong, who simulates star formation in such clouds, is eager to get his hands on the 3D maps and compare them to his simulations. So far, she says, astronomers have only looked at how supernovae affect average star-forming properties, such as the rate of star formation or the density of matter in such clouds. “But the 3D dust map really allows us to look at the structure,” she says.