Sagittarius A * (Sgr A *) is a brilliant flowering of radio waves supposed to contain the black hole in the center of the Milky Way. In this x-ray map of the galactic center, the researchers discovered two large "chimneys" of plasma coming out of the Sgr A * region and apparently pouring hot matter into two huge gas bubbles called Fermi bubbles.
Credit: G. Ponti et al.
The supermassive black hole in the center of our galaxy is a bit like the hearth in the center of a cozy pub. It is a bright and warm gathering place around which all the Milky Way's daily life is swirling – and, according to a new study published today (March 20) in the journal Nature, it could even have a fireplace or two.
In a recent study of X-ray emissions from the galactic center of the Milky Way, researchers noted two unusual structures that had never been described before. Two superhot plasma columns, emitting X – rays, seemed to overflow from the galactic center, one rising to the north and the other to the south, for hundreds of light years back and forth.
"We call it chimneys," Gabriele Ponti, study author and researcher at the National Institute of Astrophysics (INAF) in Italy, told Live Science. "Looking at them, we see clear evidence of a strong plasma flow from the galactic center." [The 12 Strangest Objects in the Universe]
The X-ray marks the place
Ponti and his colleagues found this evidence by analyzing more than 750 hours of X-ray observations taken by the XMM-Newton and Chandra telescopes. These observations helped the team create an X-ray map of the center of the Milky Way (see above), including the almost symmetrical chimney plumes emanating from both sides of Sagittarius A *, the light source radio waves supposed to surround our galaxy. a supermassive black hole.
The north and south chimneys extend about 522 light-years across the center of the galaxy and each becomes warmer and denser as they move closer to Sagittarius A *. It seems clear that these explosions of heat and matter are the result of an important exit from the galactic center, wrote Ponti and his colleagues, although the exact source is unknown. The available evidence suggests two possibilities: either the exit is caused by the supermassive black hole itself (which can be a sling throwing a material into space even as it engulfs huge amounts of gas and dust nearby ), or by periodic explosions of supernova the central star cluster of the galaxy.
"The data supports both of these scenarios," said Ponti.
Blow cosmic bubbles
The final destination of the chimneys seems clearer than their origin.
In their x-ray map, the researchers found that the north and south chimneys extend to the base of two gargantuan structures called Fermi bubbles – essentially two giant cavities of gas and cosmic rays carved into the galactic center by millions of years. d & # 39; activity.
These bubbles begin about 326 light-years above each side of the galactic center and intersect with the ends of the chimneys. Unlike fireplaces, however, the bubbles extend over tens of thousands of light-years, dominating the Milky Way like two chambers of a giant hourglass. Together, the two spheres occupy about as much space as the galaxy itself, Ponti said. (However, do not look too hard for them because they are mainly composed of gamma rays, the bubbles are invisible to the naked eye.)
Since 2010, scientists know that our galaxy blows space bubbles and think that they were probably created by a tumultuous event in the center of the galaxy millions of years ago. However, according to Ponti, the discovery of galactic chimneys marks the first direct connection between these huge gaseous orbs and the relatively tiny nucleus of the Milky Way.
"The chimneys are the exhaust pipes connecting the galactic center's activity to the Fermi bubbles," Ponti said.
Further study of the chimneys could reveal a more precise origin of Fermi bubbles. The next step, Ponti said, is to visualize an even wider part of the galactic center – to see, for example, if the flow of the chimney seems to be located above the supermassive black hole of the galaxy, or if it is extended on a larger group of stars. Whatever the case, the focus in the center of the galaxy will keep a fire burning for us, perhaps even bigger than anyone could have imagined.
Originally published on Science live.