What is this huge bubble that surrounds the Earth that scientists have just mapped?  - Third

What is this huge bubble that surrounds the Earth that scientists have just mapped? – Third

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Astronomers from the Center for Astrophysics, Harvard & Smithsonian (CfA) unveiled a one-of-a-kind map that could help answer decades-old questions about the origins of stars and the influences of magnetic fields in the cosmos.

The map reveals the probable structure of the so-called magnetic field local Bubble, a giant hole 1,000 light-years wide in the space surrounding planet Earth.

“The elaboration of this 3D map of the local bubble It will help us examine superbubbles in new ways.” Theo O’Neill, who led the mapping effort during an NSF-sponsored 10-week summer research experience at CfA while still a college student, said in a statement.

Like a piece of Swiss cheese, our galaxy is filled with so-called “superbubbles”, thick surfaces that serve as favorable sites for the subsequent formation of stars and planets.

the super bubbles They are literally like a bubble, “in the sense that is a cavity around our sun that is made up of very hot gas, in a state of plasma matter” explains Rodrigo Herrera, researcher at the CATA Astrophysics Center.

In addition, It has a very low density. “so low that no human laboratory is close to being able to recreate that level of low density that exists in the interstellar medium”, which is surrounded by a border of gas, which is neutral, much colder and of interstellar dust, adds the also astronomer from the University of Concepcion.

However, scientists’ general understanding of superbubbles remains incomplete. But with the new 3D magnetic field map, researchers now have novel information that could better explain the evolution of these, its effects on star formation and galaxies in general.

What surrounds the Earth is known as local bubble, which has become a striking topic in astrophysics since it is the superbubble in which the Sun and our Solar System now lie.

In 2020, the 3D geometry of the Local Bubble was initially worked out by researchers based in Greece and France, then in 2021 thanks to a research team it was shown that the surface of the Local Bubble is the source of all young stars. nearby.

It is defined in that way, because “deep down everything that is centered around us receives the local term ” Herrera comments.

This Local Bubble, It’s literally like a bubble that’s expanding. “That in its center it is less dense and then, it has an edge of denser and colder material that is expanding within our galaxy centered approximately on our star, the sun”, points out the CATA astronomer.

It is a body that is part of the milky way, and expands within it, but does not cause harm to human life, since “we are protected by our atmosphere and our interaction with the interstellar medium is not direct Why is there an atmosphere around our planet? which acts as a layer that separates us from the gas that is present in this bubble” explains Herrera.

To learn even more about this body, a team of astronomers, working on a summer research program at the Harvard-Smithsonian Center for Astrophysics, mapped the magnetic field of the Local Bubble.

“Space is full of these super bubbles that trigger the formation of new stars and planets and influence the overall shapes of galaxies,” O’Neill said.

“By learning more about the exact mechanics that drive the local bubble, in which the Sun lives today, we can learn more about the evolution and dynamics of superbubbles in general.” added.

The research was carried out at CfA under the mentorship of the Harvard professor and CfA astronomer Alyssa GoodmanIn collaboration with Catherine Zucker, Harvard PhD astronomy alumnus, jesse hana Harvard PhD student and Juan Solermagnetic field expert in Rome.

“From the point of view of basic physics, we have known for a long time that magnetic fields must play an important role in many astrophysical phenomenaGoodman said in a statement.

But studying these magnetic fields has been notoriously difficult, according to the researchers.

“Today’s computer simulations and all-sky surveys pThey may finally be good enough to start incorporating magnetic fields into our bigger picture. how the universe works, from the movements of small dust grains to the dynamics of galaxy clusters,” Goodman explained.

Researcher who compared the research team to pioneer cartographers who created some of the earliest maps of Earth.

“We made some important assumptions to create this first 3D map of a magnetic field; it is by no means a perfect image,” she said. “As technology and our physical understanding improve, we will be able to improve the accuracy of our map and hopefully confirm what we are seeing.”

The 3D view of the magnetic spirals that emerged represents the structure of the magnetic field of our neighboring superbubble, whether the field was indeed drawn towards the surface of the bubble and whether most of the polarization occurs there.

The short pink and purple vector lines on the bubble surface represent the orientation of the discovered magnetic field. The bubble is inside the Milky Way galaxy. Photo: World Wide Telescope

To map the magnetic field, the astronomers used previous information from the European Space Agency’s (ESA) Gaia space telescope, which had inferred the approximate boundaries of the Local Bubble from distant cosmic dust concentrations.

With this in hand, the researchers turned to data from another ESA space telescope, Planck, which showed the faint microwave emissions of polarized light from dust.

“Astronomers have theorized for many decades that supernovae can entrain gas into dense clouds that ultimately form new stars,” Zucker said. “But our work provides the strongest observational evidence to date supporting this theory.”

Earth is currently right in the heart of the Local Bubblebut that’s not what makes this location special.

“It’s coincidence that the sun is centered inside the bubble,” since the sun was about 1,000 light-years away when the bubble began to form and entered only 5 million years ago, Zucker explained.

In accordance with the Copernican principle, which states that humans are not privileged observers of the universe and that Earth has no “special” location in the galaxy, Earth’s position within the local bubble suggests that superbubbles are probably very common throughout the Milky Way, Zucker stressed.

Artist’s illustration of the Local Bubble with the location of the Sun at the center and star formation taking place on the surface of the bubble. Photo: Leah Hustak (STScI)

“We think these bubbles interact with each other, with star-forming regions at the intersections of the bubbles,” Zucker added.

The Milky Way is therefore compared to cheese, because the interstellar medium (which is what is between the stars) that is found around the young stars that formed “is irregular, so as this bubble begins to expand in different parts, it faces different levels of resistance, which is why it is that it is not a perfectly spherical or symmetrical bubble” says Herrera.

In a new study, published January 12 in the journal Natureresearchers precisely mapped the star-forming regions surrounding the Local Bubble and, in doing so, calculated how fast is the superbubble expandingwhich is currently around 4 miles per second (6.4 kilometers per second).

So the solar system will not always be trapped inside this bubble, the team discovered. “The sun should come out of the bubble in about 8 million years,” Zucker said. “But at that point, the bubble may no longer exist.”

It is believed that the expansion of the Local Bubble is slowing down and will eventually disappear after reaching its maximum size, the researcher added.

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