(ORDO NEWS) — It often seems that when people die, they leave a void behind. In the case of massive stars, this is physically true.
A new analysis of rarefied gas drifting between stars in the Milky Way galaxy has revealed the signature of bubbles that expand into space when a massive star goes supernova at the end of its life. Scientists say these ghostly trails reflect the history of star deaths and the rotation of the Milky Way.
The space between the stars is not completely empty. In these gaps, gas drifts in space, sometimes gathering into more diffuse clouds, mostly of atomic hydrogen. Stars are born in these clouds when they are dense enough; and when they die, the stars seed these clouds with the elements they have forged in their cores.
However, it is not entirely clear how these clouds are formed, ordered and recycled throughout the galaxy. So a team of astronomers led by Juan Diego Soler of the Italian National Institute of Astrophysics (INAF) in Italy set out to study the structures found in the neutral atomic hydrogen that pervades our galaxy.
The team used data collected from the HI4PI project, an all-sky survey that studied the radio sky to produce a map of neutral atomic hydrogen throughout the Milky Way.
This is the most detailed review of its kind conducted in this way. far away, mapping not only the distribution of hydrogen in the galaxy, but also its speed. By combining this with a model of the rotation of the Milky Way, researchers can measure the distance to structures in the gas.
With this data, the team used an algorithm commonly used to analyze satellite photographs, picking out fine details. structures in hydrogen that would be impossible to identify by eye.
They consisted of an extensive network of thin filaments of gas, known as filaments, located close to the disk, mostly perpendicular to the plane of the Milky Way.
Galaxy; those that were not perpendicular appeared to be randomly oriented. At large distances from the disk of the Milky Way, about 33,000 light years away, the filaments were mostly parallel to the galactic plane.
The team interpreted these networks as a supernova feedback imprint in the gas of the galaxy. Milky Way.
“These are probably the remnants of several supernova explosions that carry away gas and form bubbles that burst when they reach the characteristic scale of the galactic plane, like bubbles that reach the surface in a glass of sparkling wine,” said astronomer Ralf Klessen from the University of Heidelberg in Germany.
“The fact that we see mostly horizontal structures in the outer Milky Way, where there is a strong decrease in the number of massive stars and therefore fewer supernovae, suggests that we are recording the contribution of energy and momentum from stars forming gas in our galaxy.”
This, the team says, could offer a new probe for understanding the dynamic processes that shaped the disk of the Milky Way, and a tool for conducting galactic archeology, studying the fossils of ancient processes to reconstruct the history of our galaxy.
It also offers a new context for interpreting other phenomena that may be found near the fibers.
“The interstellar medium, which is the matter and radiation that exists in the space between stars, is governed by the formation of stars and supernovae, the latter being violent explosions that occur in the last stages of the evolution of stars that are more than ten times more massive than the Sun,” the astronomer said. Patrick Hennebel of the Saclay Nuclear Research Center in France.
“Supernova associations are very effective in maintaining turbulence and lifting gas in a stratified disk. Finding these filamentous structures in atomic hydrogen is an important step in understanding the process responsible for star formation on a galaxy scale.”
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