The Local Bubble, which originated from supernova explosions that took place in the last 15 million years, has a hollow structure that measures about 1,000 light-years across.
A group of astronomers from the Harvard-Smithsonian Center for Astrophysics (CFA, for its acronym in English) revealed how young stars close to the Sun are formed, after mapping the magnetic field of a space superbubble for the first time in 3D, reported Wednesday the American scientific institution.
In a study recently published in the Authorea prepress service, it was detailed that it is a low-density expanding superbubble, called ‘Local Bubble’which is very close to the current location of the Sun. In addition, it was suggested that the Local Bubble originated from supernova explosions that took place in the last 15 million years.
The scientists explained that given its proximity to the huge star and previous investigations of its characteristics, this superbubble was selected to have the surface structure of its magnetic field mapped. For the construction of the cartographic representation of the superbubble, data from the Gaia and Planck space telescopes, both operated by the European Space Agency (ESA), were used.
The map revealed that the Local Bubble has a hollow structure that measures about 1,000 light years across. The specialists specified that its irregular shape is due to the fact that it is surrounded by a layer of cold dust and gas, which extends up to a few hundred parsecs from the Sun. However, they clarified that when mapping the magnetic structure of the Bubble Local found a series of difficulties due to uncertainties in the geometric measurements of the cavity in the interstellar medium (space plasma) around the large star.
Superbubbles generate new stars
Analysis of the map allowed the astronomers to relate the clouds of molecules in the superbubble to the star-forming regions near its surface, thus proposing that the origin of local starslocated within 200 parsec of the Sun, was caused by the expansion of the Local Bubble.
“Space is full of these super bubbles that trigger the formation of new stars and planets and influence the general shapes of galaxies,” commented researcher Theo O’Neill, who noted that, “by learning more about the exact mechanics that drive the Local Bubble, in which the Sun lives today”, it will be possible to “learn more about the evolution and dynamics of superbubbles in general”.
Despite the results of the research, the scientific team stressed that the mechanisms that promote the formation and expansion of the superbubble are still unknown. Likewise, he indicated that the information on how magnetic fields can affect the dynamics and evolution of the bubble and, therefore, local star formation, is still limited.
“With this map, we can really start to probe the influences of magnetic fields on star formation in superbubbles,” said Professor Alyssa Goodman, adding that it will also help to understand “how these fields influence many other cosmic phenomena.”
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