Two astronomers from Greece have managed to model the three-dimensional structure of an interstellar gas cloud, and found that it’s on the order of 10 times more spacious than it originally appeared. The 3D “map” is an important step in understanding the process of how stars are born.
Greek scientists from the University of Crete and the Foundation for Research and Technology Hellas (FORTH) made an important step forward in understanding the process of how stars are born.
For the first time internationally, Greek researchers managed to three-dimensionally “map” an interstellar molecular cloud of gases and dust, a region where new stars are born, as they discovered that its magnetic field vibrates like a bell. They thus opened the way for solving one of the greatest mysteries in astrophysics: What determines the number and type of stars and planets created in our galaxy.
The discovery, which was published in the journal Science, was the core of Dr. Aris Tritsis’ doctoral thesis, which he completed at the Department of Physics of the University of Crete under the supervision of Professor Costas Tassis. It was based on the theoretical and experimental studies of the two researchers at the University of Crete and FORTH, as well as data from the ESA Herschel Space Mission.
The Greek researchers studied the case of Musca, a large isolated cloud, visible from the southern hemisphere of the Earth, which in the sky looks resembles a narrow cylinder like a needle. The cloud, consisting mainly of hydrogen molecules and located 570 light years away from the Earth under the Southern Cross constellation, is about 27 light years long and 20 light years deep, according to the researchers.
The 3D structure of interstellar clouds has been, for decades now, the ‘holy grail’ in figuring out how clouds break up into smaller fragments, and how these fragments go on to form stars,” Konstantinos Tassis, co-author of the new study about Musca and a researcher at the University of Crete in Greece, told Space.com in an email.
By reconstructing Musca’s 3D structure, Tassis and astronomer Aris Tritsis aim to test theoretical models of interstellar clouds and advance scientists’ understanding of how stars are born
picture – Aris Tsitsis
Tassis and Tritsis studied the cloud’s vibrations, which are encoded in striations, or the hair-like structures that surround it.
- Musca vibrates magnetically as a whole, or “sings,” as the researchers put it. This “song” is what eventually led the team to determine the 3D structure.
“The process of astrogenation remains one of the biggest unresolved problems in astrophysics,” Tassis said to the Athens-and Macedonian News Agency. “We know that stars are born in interstellar gas clouds of ‘astronomical’ dimensions, but what how exactly we get out from clouds to stars like our sun and the planets is still a mystery. What determines if a cloud will make many small stars or a few big ones? What percentage of the cloud gas will be converted into stars and how much will be recycled?”
The nature of the striations themselves is not yet fully understood, according to Tassis, but their work suggests how to interpret them as the imprint of magnetic waves traveling through the cloud they’re in, because the waves reflect the cloud’s structure.