It may not seem like it to us, but the space between the stars is not completely empty. Clouds of gassed, sometimes not so gassed, float in this gloom.
One region about 700 light-years away from us is an exception in this regard. There, between the constellations of Perseus and Taurus, astronomers discovered a vast, spherical-shaped void (void) 500 light-years in diameter. Around its perimeter are the molecular clouds of Perseus and Taurus – clouds of cold gas and dust in which new stars are born.
It was called the Perseus-Taurus shell, which appears to have been formed by the explosion of at least one giant supernova millions of years ago. Presumably, this phenomenon led to the process of star formation in two molecular clouds.
“On the walls of a giant balloon, hundreds of stars are born or already exist,” said Shmuel Bial, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.
According to him, they have two theories – one supernova exploded in the center of this bubble, the gas passed outwards and formed the “Perseus-Kuro membrane”; Or for millions of years, there have been a series of supernovae.
Mapping objects in space is a very difficult task. In two dimensions this can be done directly, but in three-dimensional depth it requires a little more labor. There are several ways to do this, but there are some gaps in our knowledge, and many things are still unclear.
To study the molecular clouds of Perseus and Taurus, the researchers used Gaia data. Gaia is a European space agency spacecraft that has been working since 2013 to create the most detailed and accurate three-dimensional map of the Deer Leap by this time. It is one of the most powerful tools we can use to study the architecture and history of our galaxy.
Imaging software called glue was used to process his data, allowing scientists to create interactive 3D visualizations. As a result, astronomers have created 3D maps of these and other molecular clouds.
“We have been seeing these clouds for decades, but we never knew their true shape, depth and thickness. We also did not know exactly how far away they were from us. “We now know where they are, with 99 percent accuracy, so we can see the void stretching between them,” said Catherine Zucker, an astronomer at the Harvard-Smithsonian Center for Astrophysics.
According to the Bial Group analysis, an almost spherical void is likely to have formed as a result of a powerful supernova explosion, which sent shock waves in all directions into interstellar space. As the shock waves propagated, they pushed matter into interstellar space and compressed it, forming a spherical membrane.
All of this also reveals how the star-forming process can begin in molecular clouds.
“There are many different theories about how gas is arranged to form stars. “These theoretical ideas have previously been tested by astronomers in simulations, but now is the first time we can use real rather than simulated 3D views to compare theories with observations and to discover the best theory among them.”
Stellar formation is thought to occur when a dense region of a molecular cloud collapses by its own gravity and begins to rotate. When the shock wave of a supernova explosion expands the space around it, the gas moves into interstellar space and forms molecular clouds with dense regions in which new stars then begin to form.
According to a group of researchers, this is exactly what happened in the case of the Perseus-Taurus membrane. Their reconstruction indicates that 6-22 million years ago, many supernovae “cut” a gap in interstellar space. Thus formed both the membrane and the molecular clouds of Perseus and Taurus. As observations indicate, the bladder is no longer expanding.
“It shows that when a star dies, its supernova explosion creates a chain of events that could eventually lead to the birth of new stars,” said Samuel Bial, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.