Amazing – and informative: Astronomers render new images of our neighboring galaxies in a variety of colors, giving astronomers insight into the processes of star formation. The images provide detailed insights into structures in particular young stars as well as the gas formations that heat them up around them. Together with other data, these observations may now provide new insights into the mechanism by which matter excites to form stars, the scientists explain.
They are like the cities of the universe: In galaxies, billions of stars and the matter around them form complex structures through gravitational forces. It is generally known that stars are born in clouds of gas, but there are still many questions about what triggers stellar evolution and the full role of each galaxy. To gain insight, it is necessary to make images of galaxies and their nurseries as complex as possible. A team of international astronomers is working towards this goal as part of the PHANGS (Physics at High Angular Resolution in Near Galaxies) project. Now they are rendering some of our neighboring galaxies in detail and color at an unprecedented level.
Scientists capture cosmic structures with powerful telescopes on the ground and in space and target specific regions in a precise manner. Various observatories were selected so that the team could capture our galactic neighbors at different wavelengths. The color complexity highlights the different parts of the observed galaxies. The Multi-Unit Spectroscopic Explorer (MUSE) of the European Southern Observatory’s (ESO) Very Large Telescope (VLT) made the targeted view of the galactic nursery possible. Astronomers used this instrument to track newborn stars and the hot gas around them. As they explain, this matter is illuminated and heated by stars and thus may provide clues to the processes of star formation.
“For the first time, we are now resolving distinct star formation regions in a selection of galaxies with distinct regions and environments that represent different forms,” says co-author Erik Amselm from ESO in Germany. The combination of the data enables scientists to better study the different stages of star formation than previously thought. “With FUNGS, for the first time we have been able to develop a complete image, which is sharp enough to see individual clouds, stars and nebulae,” says co-author Francesco Belfour, of INAF-Arcetry in Florence.
Atlas of Galactic Nursery
As part of the project, researchers are combining new MUSE images with observations of the same galaxies that were recently created using the Atacama Large Millimeter/submillimeter Array (ALMA). These images are particularly suitable for mapping cold gas clouds – objects in galaxies that provide the raw material for star formation. As the astronomers point out, the combination of MUSE and ALMA images enables comparisons that can provide particularly revealing insight into what triggers, enhances or reduces the birth of new stars.
Astronomers have already been able to map the gas clouds in 90 nearby galaxies and thus create a previously unparalleled detailed atlas of stellar germ cells in the nearby universe. This could serve as a basis for further research: “There are many puzzles that we want to understand,” says co-author Katherine Krekel of Heidelberg University. “Are stars born more frequently in certain regions of their host galaxies? And if so why? And how does the evolution of these stars after their birth affect the formation of new generations of stars?” Thanks to this, astronomers can now pursue these questions in a targeted manner.
The PHANGS team will now stick to the ball. “So far, the resolution of the maps we have created is sufficient to identify and isolate individual star formation clouds, but it cannot yet explain why,” says co-author Eva Schiner, from the Max Planck Institute for Astronomy What is happening to them?” in Heidelberg. In this context, scientists are now looking forward to the extension of mankind’s cosmic eye: NASA’s James Webb Space Telescope and ESO’s Extremely Large Telescope (ELT) will soon enable even more detailed views of the structures of star formation regions. “We have decades of exciting discoveries ahead of us,” Schiner concluded.
Caption: Examples of five galaxies recorded as part of the PHANGS project. (image: eso/fangs)