Astronomers find a protective shield at the Magellanic clouds

American astronomers have reported the discovery of a “corona” surrounding the Large and Small Magellanic Cloud. It acts as a protective shield, helping them to keep their shape and support the formation of new stars.

Invisible protective shield

Our Milky Way has a number of moon galaxies. The largest and most famous of them are the Large and Small Magellanic clouds. Calculations show that they are gradually approaching the Milky Way and will merge with it in billions of years.

The star-rich region around the Tarantula Nebula in the Large Magellanic Cloud. Source: ESO

The process of approaching the Milky Way is accompanied by the release of gas from both galaxies. But at the same time, they both still retain their shape and actively form new luminaries. Many scientists have long assumed that there is some mechanism that protects the Magellanic clouds from the complete loss of gas reserves. Computer simulations have shown that the best candidate for the role of such a shield is the “corona” — an extensive shell of ultra-hot gas that surrounds galaxies like a cocoon. But until recently, this remained only a theory. Since the corona is practically invisible, astronomers could not confirm its existence in any way.

Finding the corona of the Magellanic Clouds

Everything changed after the publication of the article in the journal Nature. It contains the results of a study conducted by a team of American astronomers. They managed to prove the existence of a corona in the Magellanic clouds.

Illustration of the relative position of the Sun, the Milky Way, the Magellanic clouds and their surrounding corona. Source: STScI, Leah Hustak

To discover the corona, scientists studied the archive of ultraviolet observations of the Hubble telescope and the FUSE satellite for 28 quasars. They are in the sky in the same area where the corona should be located. The researchers reasoned that even though the corona is too dim, it should still create something like a “fog” that will weaken the light from the background objects behind it.

Subsequent analysis confirmed the existence of the corona. It stretches for 100 thousand light-years from the Magellanic clouds. According to scientists, it is a remnant of the primary gas cloud from which these galaxies once formed. Nowadays, the corona plays the role of a protective barrier that slows down the gas ejected from the Magellanic clouds and prevents it from escaping into intergalactic space.

According to

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